Tarsal Tunnel Syndrome

Picture from Orthopaedia.com

A patient came in to our clinic declaring she has plantar fascia pain in her right foot. She had seen another physiotherapist a few years ago for plantar fascia pain in her left foot and had gotten better. This time she tried orthotics, lots of stretching and even shockwave (or ESWT) with the same physiotherapist, but there was no improvement.

This is how she described her foot pain. She said there was a burning, aching pain at the bottom of her foot and on the inner heel. She said it almost feels like an electric shock. Her pain gets a lot worse after prolonged standing and sometimes wakes her up at night. She also gets numbness in her toes. 

None of those symptoms sound like plantar fascia pain to me. Patients with plantar fasciitis usually have pain during the first few steps when they get out of bed in the morning. There is rarely numbness, burning or electric shock sensations in the toes.

Upon assessment, there was no pain on the posterior calcaneal tubercle (where the PF inserts) nor along the plantar fascia itself. 

I elicited her pain when I did a modified Straight Leg Raise test by holding her foot in full dorsiflexion and eversion. However, there was no tingling or zinging in the foot when I tap on the medial malleolus (over the tarsal tunnel) - also known as Tinel's test. Online articles often describe a positive Tinel's test.

I explained my findings to her. My patient actually has Tarsal Tunnel Syndrome. This is when the posterior tibial nerve gets 'trapped' and irritated in the tarsal tunnel at the inner part of the foot (pictured below). 

Picture from Teachmeanatomy

The tarsal tunnel is a space just behind and below the medial malleolus and serves as a passageway for the posterior tibial artery, nerve and what we call Tom Dick and Harry muscles (tibialis posterior, flexor digitorum longus and flexor hallucis longus). The 'roof' of this tunnel is covered by the flexor retinaculum. It is a thick and strong fibrous band that holds Tom, Dick and Harry in place.

Tom, Dick and Harry- back of R leg

Entrapment of the posterior tibial nerve in the tarsal tunnel caused my patient's foot pain, not plantar fasciitis.

Online or AI* searches always say that flat feet or severe overpronation can cause tarsal tunnel pain as it can stretch the nerve although my patient does NOT have flat feet.

My patient did have a severe right ankle sprain a few months ago that caused swelling and perhaps thickening in the connective tissue in the tunnel that eventually caused this. It was also not treated properly, causing her to compensate and stand and walk differently possibly 'tractioning' her posterior tibial nerve.

A ganglion cyst in the canal may also cause this since it reduces the space in the tunnel. I have never come across this though in the 27 years of being a physiotherapist.

When a patient complains of bottom of foot pain, plantar fasciitis is usually the diagnosis one thinks of. The symptoms of tarsal tunnel syndrome pain can be similar to lumbar radiculopathy, diabetic and peripheral neuropathy or plantar fasciitis. Hopefully this article will correct that. 

 (*All the articles in this blog are written by me not by AI).

Reference

Boers N, Haverkamp M, Eligh AM et al (2026). Differences in Diagnosing Tarsal Tunnel Syndrome Across The Literature: A Systematic Review And A Call For Standardization. JBJS Rev. 14(2): e25.00222. DOI: 10.2106/JBJS.RVW.25.00222

L flexor retinaculum

Picture from https://drjustindean.com/retinaculaofthefoot/

Can Cross Training On A Bike Translate To Better Running Performance?

Picture from Bikatadventures.com

I had shin stress fractures in both legs from running too much when I was 20. The doctor I saw said that I could not run for a minimum of 6 weeks. I could only swim or bike. It was this cross training regime that got me started in triathlon later.

This concept cross training emerged in the 1980s along with the popularity of triathlon. Earlier studies reported that performance in a primary sport can be maintained despite reductions in volume of the primary sport by training in a variety of sports. These findings suggest potential crossover effects between endurance training modalities. Are these findings still relevant?

The following systematic review by Menges et al (2026) compared the effects of running only and cycling only training interventions to evaluate cross training transfer to sport specific VO2 max and running performance.

The authors found 7 studies with intervention durations of at least 4 weeks. These were run only training with cycling only or combined running-cycling interventions. Outcomes included VO2 max assessed on a treadmill or cycle ergometer as well as running time trial performance for 1 mile, 3000m and 5000m.

So does cross training on a bike help running performance? This meta-analysis suggests it does. The subjects who performed run only, bike only or combined running and cycling training performed similarly in the 1 mile, 3000m and 5000m time trials. They also had improved VO2 max values regardless of testing method (treadmill or cycle ergometer).

Cycling engages the quadriceps and gluteus maximus muscles in ways that running does not. When the muscles get stronger, it helps improve running economy and power (especially in hilly races).

Instead of running twice a day, you can take away some of the extra strain on the legs by cycling (or even training on the elliptical machine) without the repetitive impact forces of running. This is especially beneficial during recovery periods or for runners prone to injuries.

Cycling is low impact which is great for your joints. However, it does little to help your bone density. Running on the other hand has impact loading that helps to maintain or even increase bone strength which is great for older athletes.

The findings should be interpreted with some caution since there were limited studies (7) and the fairly short training period.

For shorter distances up to 5 km at least, there may not be any differences but in a longer event like the marathon, you still need to run since the run muscles will not used as much while cycling. Biking can definitely help the aerobic fitness but not the specific leg muscles, and running performance may decline.

Running and cycling can actively enhance each other when integrated carefully. If you're a runner looking to improve your endurance without extra impact or a cyclist looking for stronger stabilizing muscles, cross training helps.

The key is balancing both to meet your specific training goals while avoiding overuse injuries.

The principle of specificity suggests that cross training can offer general fitness benefits, the most significant performances are achieved through sport specific training. Before Sabastian Sawe broke the 2 hour barrier for the marathon, he was running in excess of 200 km a week in the 6 weeks leading up to London, with a maximum of 241 km (150 miles). 

So, runners and cyclists should incorporate cross training as a supplementary activity rather than a replacement for their primary sport.

References

Menges T, Dindorf C, Dully J et al (2026). Cross-Training Between Rnning And Cycling: Effects On VO2 Max And Running Performance- A Systematic Review And Meta-Analysis. Front Sp Act Living. 8: 1843803. DOI: 10,3389/fspor.2026.1843803

Tanaka H. (1994). Effects Of Cross-Training. Sports Med. 18: 330-339. DOI: 10.2165/00007256-199418050-00005

Carbon Plated Shoes And Stress Fractures

Picture from Prodirectsport

I just saw 3 different people wearing carbon plated shoes at the Cold Storage in Holland Village. They were shopping for groceries and definitely not running. On one hand you have someone like me who's still unwilling to run in carbon plated shoes while on the other hand they are a dime a dozen amongst runners now (and people walking in Cold Storage). Most runners use them in training as well, not just at races. 

No running study has studied whether carbon plated shoes (known as advanced footwear technology or AFT) changes running biomechanics associated with bone stress injuries (BSI), or shin splints. The researchers goals were to measure running biomechanics while running in an AFT shoe.

23 runners (11 women, 12 men) with an average age of 25.4 ± 2.7 years were recruited for the study. They ran randomly in 3 different types of running shoes, neutral, lightweight (responsive foam) and AFT at 3 self selected running speeds. A run at their 'training effort', a tempo run and at 5 km race pace.

Biomechanical variables associated with BSI such as cadence, vertical ground reaction forces, ankle and rearfoot eversion forces were measured during each run and shoe condition.

Results show that with neutral running shoes, ankle plantarflexion moment was higher compared to lightweight foam and AFT. There was less rearfoot eversion movement in the neutral shoe compared to lightweight foam and AFT. 

Cadence was lower while running in AFT shoes  compared to neutral or lightweight foam shoes. This is relevant since a longer running stride has been linked (in earlier studies) to BSI in the lower limbs.

Rearfoot eversion velocity (the speed at which your foot rolls down and inwards), or pronation was higher in the lightweight foam shoe compared with both neutral and AFT shoes. There was no significant difference in this between the neutral and AFT shoe.

The authors concluded that there were increases in several biomechanical variables associated with BSI  while running in AFT shoes. Although these changes were small, they tend to accumulate and can contribute to increased forces on bones in the lower limbs.  

The authors suggest that rotating running shoes and gradually using AFT to adapt to the differences may help reduce potential injury risk while optimizing running performance.

Reference

Bruneau MM, Gaudette LW, Sirls E et al (2026). Biomechanics Associated Withe Bone Stress Injuries While Using Advanced Footwear Technology In Elite Distance Runners. PM & R. 18(2): S143-150. DOI: 10.1002/pmrj.70153

Repeat The Same Training?

I started keeping a handwritten training log (pictured below) after I started running at 13. Back then there were no apps to keep such records for you. I would record how far I ran, time taken, how I felt, what shoes I used, etc. 

I found it useful so I could look back on what training I did when taking part in a similar event. Say my key interval workout for a 1500m track race that I had won previously was 8x200m with 30 seconds rest. I would replicate those sessions along with deciding if I could handle more. Back then, I was a teenager and was able to run personal bests in all my events every year.

I assume that when I responded well to a training program once, I'd respond similarly or better the next time. However, a recent study suggested otherwise.

A group of researchers had subjects do the same 8 week endurance training program twice, but separated by a period of detraining that had to return to baseline. 42 out of the 53 recruited completed the study.

Each 8 week period had 24 supervised 45 minute interval cycling sessions at moderate to maximal intensity. Identical training instructions were applied such that the same training program was repeatedly prescribed to the same individuals. Exercise intensity was individually prescribed relative to performance and adjusted every second week to mainatin a comparable training stimulus across periods.

Results show very poor reproducibility of adaptation. One athlete increased VO2 max by about 600mL min⁻¹ after the first training period. However, there was no improvement at all after the second training period. Yes you read correctly, zero improvement.

Same athlete, same program, but very different outcome. I asked a few coaches whom I treat if this was similar to the athletes they coach. They told me they see it all the time. Training response varies.

The training may be the same but the variations in external factors such as sleep, diet, work stress, travel and illness contributes to the variability in individual training adaptations.

That's what the researchers concluded too. The substantial within-individual fluctuations were largely consistent between training periods and they suggest that this  within-individual fluctuations does not reliably reflect their capacity to adapt to the same training stimulus in the future.

So low stress plus good training leads to adaptation while high stress plus the same training may lead to very different outcomes.

Take away message? Do not assume that because a program worked once, it will work the same way the next time. Monitor the state of your own life stresses and modify accordingly.

Reference

OddenIV, Hamarsland H, Odden TU et al (2026). Limited Reproducibility Of Individual Physiological Adaptations To Repeated Endurance Exercise Training. J App Phy. DOI: 10.1152/japplphysiol.00154.2026

Can You Trust AI With Nutritional And Athletic Performance Advice?

Picture from Sixminutemile.com

I was reading about how 2024 Olympic road race cycling winner Kristen Faulkner built her own artificial intelligence (AI) model to analyse 9 years of her own performance data to help her uncover what's missing from women's sports science. It allowed her to have data that helps explain not just what happened but why.

Faulkner said she coded to build the AI technology that can learn from data, spot patterns and make decisions. These are skills that we usually associate with human intelligence. 

AI is already in our everyday lives. We get Google Maps directing our commute, Spotify suggesting songs on your playlist and hit ChatGPT with any question we might have.

Many people use AI for everyday health, exercise and medical queries. Are these AI driven chatbots reliable and accurate? Our patients already use AI to self diagnose their pain and injuries. Some studies show chatbots are largely accurate, while others reported frequent errors and even a risk for transmitting inaccurate information.

The following research investigated 5 popular AI driven chatbots to evaluate their responses to everyday health and medical queries across 5 categories: cancer, vacines, stem cells, nutrition and athletic performance. Both open ended and closed ended questions were used.

Gemini, Meta AI, DeepSeek, ChatGPT and Grok were the 5 chatbots used. They were each presented with 50 prompts across the 5 topics mentioned above. The researchers used an adversarial framework to strain models towards misinformation or contraindicated advice.

An adversarial framework refers to a system, process or analytical model structured around opposition, competition or conflict. This is a cybersecurity approach used to test the vulnerabilities of AI systems.

Responses were then independently rated by 2 domain experts as non-problematic, somewhat problematic or highly problematic. Citations were assessed for authenticity and completeness while readability evaluated using the Flesch Reading Ease score (100 point scale with higher scores being easier to read).

Results showed that nearly half of ALL responses (49.6 percent) were problematic, 30 percent somewhat and 19.6 percent highly problematic. Nutrition and athletic performance topics had the weakest performance and Grok generated significantly more highly problematic responses than expected.

Reference quality was poor across all chatbots. The median completeness score was 40 percent. No chatbot came up with a fully accurate reference list. Misleading, unreliable or fabricated citations were common. So please be careful if you use them.

All the 5 chatbots produced responses that were rated "difficult" on the Flesch Reading Ease scale, equivalent to university-level reading. Chatbots answered consistently with confidence regardless of accuracy, while rarely declined to respond (2 refusals to answer across 250 total responses).

The researchers concluded that continued deployment of AI chatbots without public education and regulatory oversight risk amplifying health misinformation. Especially in the field of nutrition and athletic performance. They also suggested that public education, professional training and regulatory oversight to ensure that generative AI support rather than replace professionals.

My suggestion when searching for health information is to treat these AI chatbots with a good amount of skepticisim and to verify information with qualified professionals or peer-reviewed sources. There will be some benefit seeking ideas and initial information from a chatbot, but beyond that you will need a real human expert.

Reference

Tikker NB, Marcon AR, Zenone M et al (2026). Generative Artifical Intelligence-Driven Chatbots And Medical Misinformation: An Accuracy, Referencing And Readability Audit. BMJ Open. 16(4): e112695. DOI: 10.1136/bmjopen-2025-112695.

New Way Of Grading ACL Tears

A group of researchers have introduced a new way of grading anterior cruciate (ACL) tears that are relevant to ACL healing potential. This is based on the results of managing 1080 active individuals and athletes using the Cross Bracing Protocol

Remember the Cross Bracing Protocol (CBP)? These are patients who are managed conservatively without surgery, they are put in a brace to allow ACL healing to occur.The injured knee is kept at 90 degrees of knee flexion to reduce the gap between the ruptured ACL remnants. Research shows that 90 percent people regain continuity of the fibers after 3 months of treatment in the CBP. 

Yes, the torn ACL can heal when both ruptured ends attached to each other while the knee is in a bent position. However, more severe ruptures are the least likely to achieve optimal healing.

Not all ACL's that heal (or regain continuity of fibers) in studies had a normal appearance on MRI. 50 percent of subjects in the KANON trial had a normal appearance ACL, the other 50 percent had a thinner/ elongated continuous ligament (Filbay et al, 2023). 

56 percent of those with a continuous ligament 3 months post CBP treatment had a thick ligament with normal course. The other 44 percent had a thinned/ elongated continuous ligament.

In this currrent study, subjects with a thick ACL with normal course at 3 months had better 12 month outcomes when it came to knee function, quality of life and return to sport.

In addition, the following characteristics may affect the likelihood of achieving an optimal healing outcome. Patients with partial avulsion of ACL tissue from the femoral attachment are more likely to have a suboptimal healing or even no healing compared to those with the femoral origin intact (pictured above).

Displacement of the ACL ligament outside the intercondylar notch is also associated with suboptimal healing when managed with CBP. This may be due to a significant disruption to the synovial sheath that encapsulates the ACL. Disruption of this sheath negatively impacts healing potential.

If the distance of the gap between the 2 ends of the ruptured  ACL is too wide (assessed by measuring the largest distance between the torn ends of the ACL), optimal healing is less likely to occur. Among the first 80 people in this study, 7 out of 40  (18 percent) patients achieved a thick/ taut ligament healing had a gap of ≥7mm on MRI.19 out of 32 (59 percent) had a thinned/ elongated ligament while 7 out of 8 (88%) had no ACL healing at 3 months.

When one or both ends of the ACL stumps appear rounded or retracted, also know as ACL involution, it is usually the early stages of a 'non-heal' and may correspond to poor or no healing. This is observed commonly in patients who present for MRI more than 3 weeks post ACL tear.

Besides the above, meniscal injuries, another ligament injury, articular cartilage damage, osteoarthritic features, bone bruising and joint swelling may also affect the likelihood of achieving optimal healing.

The authors concluded that with further research they may be able to assist people in making an informed treatment decision of the likelihood of individuals achieving optimal healing with nonsurgical management.

Reference

Filbay S, Dowsett M, van Haeringen M et al (2025). A New Way Of Grading Severity Of ACL Rupture On Acute MRI To Consider Potential For Noin- Surgical Healing With Cross Bracing Protocol: ACL Acvute Rupture  Characteristics For Healing (ACL-ARCH) MRI Criteria. J Sci Med Sp. 29: 145-148. https://www.jsams.org/article/S1440-2440(25)00411-6/fulltext

Is Your Evening Workout Costing You Sleep?

Picture from Sitnsleep.com

I read that the Kenyan runners usually ran at least twice a day. The first run when it's still dark between 6 to 630 am to beat the heat. It is usually an easy progressive run though sometimes long runs or fartleks can take place. 

A second session often takes place between 10-11 am. This is usually reserved for track interval sessions. Typically they do 2-3 key interval sessions a week with most of the runs really easy so they can recover. When asked why they do the second run before lunch, the reply is so that they have more time to recover before the next day's sessions. 

Sometimes they even do a lighter recovery run between 4 to 5 pm to add to their weekly mileage.

So I was not surprised when I read that the timing of our workouts can affect our sleep (Akhtar and Eleftheriou, 2026). To avoid confounding factors, sleep and activity data from the same day through a model with fixed effects and terms for activity time, activity-sleep gap and the interaction between these terms. 

Data collected from users sleep looked at how sleep was affected by when they decide to exercise. The focus was on cardiovascular exercises, specifically walking, running (outdoor and treadmill), cycling (outdoor and stationary) and hiking. They studied over 100,000+ workout sessions and found that the later you train, the worse you recovered (pictured above).

When you exercise later in the day, your sleep heart rate is higher, your heart rate variabilty (HRV) is lower and you get fewer REM sleep events. You may sleep quicker with later workouts, but it is not better sleep. It is falling asleep faster while recovering less.

The benefits plateau around the 10 hour mark. The sweet spot is a 11 to 14 hour gap between your workout and bedtime. If you can exercise earlier in the day, you can capture most of the benefits. Perhaps that's the reason the Kenyan runners do their second run at 9 am. 

What about those people who can only exercise at 8pm onwards or later? Should you worry about this?  My take is no. Majority of people should NOT worry. I think it is more important to exercise where it fits in your life. 

Don't worry too much about HRV scores or perfect recovery. You are only working out at 8 pm or later because that's the only time when family and work gives you an opportunity to. Many people do not have the luxury to choose the time to exercise and exercising at any time is better than no exercise.

Our bodies are remarkably adaptable too. I am sure if you exercise at 8 pm or later long enough your body will get better sleep. Not perfect sleep but the detriment is less.

Showing up and exercising is way more important than perfect conditions. Consistency beats optimization every time. That is what will compound.

Reference

Akhtar F and Eleftheriou K (2026, May 24). Your Evening Workout Is Costing You Sleep. Terra API. Https://trryterra.co/research/best-time-toworkout--for-sleep#the-honest-takeaway

Warming Up Body And Mind

Picture from Healthywomen.org

All of us are familar with warm ups. Before you run, exercise and especially before a race. You are trying to increase your core temperature, send more blood flow to the limbs and 'wake' the muscles up. Before a running race you may even try some race pace striding so the actual start of the race does not feel like a shock.

So I was surprised to read that combining mental and physical warm ups can improve running times. Curious? Please read on to find out more.

Researchers in that study investigated whether combining cognitive tasks with a standard physical warm up could improve 1-mile performance in runners. 25 runners (11 male, 14 females) with an average weekly mileage of 20 miles (32 km) and 5km personal best timing of 23:31 min were recruited for the study. Each runner completed 3 separate testing sessions.

First was with only a physical warm up which included a 1200m easy jog, 800m alternating 100m jogs and 100m strides and 3 minutes of active stretching drills. 

Next was the same physical warm up plus a low load cognitive task and finally same physical warm up with a high load cognitive task.

In the cognitive warm up conditions, the runners completed four 3-minute cognitive tasks before and between the physical components.These tasks targeted mental functions like switching between tasks, decision making, inhibiting responses to stimuli and memory. They were doing short bursts of focused mental work designed to activate the brain without exhausting it.

 

After that all the runners ran 4 laps of a 400m track with their watch face covered so that they could only rely on feel rather than constant pace feedback.

Ready for the results? The runners were faster after both cognitive plus physical warm ups compared to only doing the physical warm up. The  low load cognitive task improved 1-mile timing by about 8 seconds (2.3%),  while the high load cognitive task improved performance by about 11 seconds (2.8%).

The runners did not appear to muscle their way to faster timings since their perceived effort was lower after the combined warm ups and their average heart rate during the time 1-mile run was also lower. Their readiness to perform was higher, meaning the runners felt more prepared to run hard.

Stride length and cadence did not change meaningfully suggesting that performance boost was not explained by obvious mechanical changes.

Take home message? No, you do not need to download an app to challenge your cognitve skills before every workout or race. However, this study does suggest that the best warm up should prepare both mind and body.

Before you do your track interval sessions, time trials or short, hard and fast sessions or even up to a 5 km race, it may be useful to add a small cognitive task that perhaps include coordination games, quick reaction tasks, fast feet with visual cues to make you engage attention before you start running hard.

The important thing to note is dose. A few short mental tasks coupled with jogging, drills and race pace striding may help you feel sharper and more ready for your workout. A long, draining task may do the opposite.

This sharpens the nervous system rather than stressing your brain. Keep it brief and engaging and please try it in your training first before trying it on race day.

Reference 

Mortimer, H Dallaway N, Diaz-Garcia J et al (2026). Warming Up The Body And Mind: Bombined Cognitive And Exercise Priming Improves 1-Mile Time Trial Performance In Recreational Runners. Eur J Sp Sci. 26(5): e70163. DOI: 10.1002/ejsc.70163

New Guidelines For Fueling

I was sharing with some my patients this past week how I found it amazing that Sebastian Sawe was able to consume 115 grams of carbs an hour in his sub-2 hour marathon. Previous recommended guidelines were between 60-90 grams an hour.

Lo and behold, a patient shared that in the Nice Ironman last year, Casper Stornes (1st place) and Kristian Blummenfelt (3rd) took 120 grams of carbs while running and up to 180 grams on the bike.

Intrigued by what he sent me, I found a recently published review article by Morton et al (2026) which revisits carbohydrate guidelines for endurance athletes. So are the previous fueling recommendations enough?

When training and/ or racing for prolonged periods, carbohydrate intake will spare liver glycogen while maintaining your blood glucose levels. Most importantly, it helps one to sustain higher intensities nearer the end of your race. When everyone else is going faster, you do not want to run out of fuel and slow down.

Fueling is not to just avoid bonking (or hitting the dreaded wall). It is also to delay the shift from using carbohydrates to fat. That shift is not bad, but when you are trying to go fast without carbohydrates it is going to be very difficult. Note that if you are doing Zone 1 or 2 for many hours (like in an ultra marathon) at low intensities, then this shift may not occur.

When one consumes enough carbohydrates during endurance exercise, long ultra race, Ironman event etc, it delays the "crossover point".  This is when carbs stop being the predominant fuel due to glycogen depletion or low carb availability.

You can see from the diagrams above that if no carbs are consumed (0 grams each hour), this happens around 2 hours. With 45-90 grams/ hour, it delays the crossover point by 30-60 minutes. If 120+ grams/ hour of carbs are consumed, there is no crossover point since carbohydrates remain the predominant fuel source while exercising. At least not in cycling studies as the subjects exercised at 90 percent lactate threshold for 3 hours. It may still occur in longer races.

For runners, the review looked at elite male marathoners with personal bests under 2:30 hrs. They completed a 2 hour treadmill protocol close to marathon race intensity while consuming 60, 90 or 120 grams of carbs each hour. 

Those who ingested 120 grams used more of the ingested carbs leading to higher carbohydrate oxidation. They had a roughly 3 percent improvement in running economy compared to 60 grams per hour. There was also greater carbohydrate contribution to total energy expenditure late in the run. Now you know why Sabastion Sawe never slowed down in his sub-2 hour London marathon. 

There's a catch. Gastrointestional (GI) symptoms were also higher at 120 grams/ hour. Nausea, stomach fullness, and cramping were worse in the highest carb intake. More carbs may offer an advantage, but only if your gut can absorb and tolerate them.

The researchers say that runners should use 90 grams of carbs or more per hour as a realistic target for long, hard events. For trained athletes, the range may extend closer to 120 grams per hour. Fueling should be treated like a trainable skill, provided the gut has been trained to handle it.

Runners will find it more challenging compared to cycling since it's much easier to eat on the bike. All the moving, reduced blood flow to the gut, heat stress may lead to higher rates of GI distress.

This is an exciting review for fueling, but do note that most of the research comes from cyling, male athletes and in controlled lab settings. Female athletes are under-represented as well as real world running/ racing conditions.

My takeaway message? For some of you runners, 90-120 grams/ hour will most certainly help your times. Others may benefit from 60-75 grams/ hour. For other runners, it may be just progressing from under-fueling to consistently fueling and getting a personal best no matter how many grams of carbs that may be.

Reference

Morton JP, Fell JM, Gonzalez JT et al (2026). From Metabolism To Medals: Contemporary Perspectives And Revisiting Carbohydrate Guidelines For Fueling Endurance Athletes During Exercise. J Nutrition. 156(5). DOI: 10.1016/j.tjnut.2026.101442

Sub 2 Hour Marathon

Back in 2017, renowned sports scientist Dr Ross Tucker wrote that a sub 2 hour marathon was unlikely to occur for generations. Then Nike introduced the Breaking 2 project which resulted in Eliud Kipchoge running under 2 hours albeit in a paced setting, not in an official race. 

The 2 hour barrier was finally broken last week at the London marathon when winner Sabastian Sawe and runners-up Yomif Kejelcha achieved the breakthrough, the latter running only his first marathon.

The podium

Sawe beat the previous world record by 65 seconds, finishing in 1:59:30 hrs. He ran an amazing negative split, 60:29 for the first half and the next half in 59:01 min. Kejelcha finished 2nd in 1:59:41 hours. The race was so fast that third place finisher Jacob Kiplimo also broke the previous world record (set in 2023) by 7 seconds. He clocked 2:00:28 hrs.

What lead to the breakthrough? Perhaps due to a "perfect storm" or convergence of many of the following factors. 

Sawe's team said he was running in excess of 200 km a week in the 6 weeks leading up to London, with a maximum of 241 km (150 miles). The volume of his training runs is likely an important factor for him to break 2 hours. Not many elite runners can tolerate that sort of volume, especially when most of it is done at low intensity (or Zone 1). High training volume done at relatively low intensity (Zone 1) is associated in faster marathon performances (Muniz-Pumarez et al, 2024).

Sawe's 5 km splits from 30 km onwards were superb. 30-35 km : 13:54 min, 35-40 km : 13:42 min. His final 2.2 km was 5:51 min. His 24th mile was 4:12 min - the fastest single mile ever run in a marathon. As the finishing line beckoned, he was still accelerating. No way he could have done this if he was not fueling well.

Sawe's nutrition was exceptional. I'm not plugging names here, in fact I've not even tried their products, but Sawe is a Maurten athlete. Elite athletes train their gut take up to 120 grams of carbs while competing without GI distress. The previous recommendation was 60 grams per hour previously. Sawe's reported intake was 115 grams an hour. Maurten's research team was with Sawe in Kenya for 32 days across 6 trips between last year and this April to train his gut to absorb that amount. 

Please note that 120 grams of carbs are NOT recommended for the recreational athlete. That is probably why cycling races and marathons are getting faster since there is no depletion in carbohydrate levels.

Sawe also used sodium bicarbonate (also from Maurten) to buffer his lactic acid build up during the race. He took the sodium bicarbonate early since it peaks in the bloodstream  roughly 60-90 minutes after ingestion so the timing of 2 + hours before the race would put peak buffering capacity at the start.

What about his shoes? Adidas says those were the fastest and lightest super shoes ever made. Actually, Adidas had a great day as 4 of the top 5 men were wearing the same Adizero Adios Pro Evo 3. It weighs 97 grams (for men's size 9), 30 percent lighter than its predecessor with a stack height of 39 mm (below the 40 mm limit by World Athletics). 

The Lightstrike Pro foam used is 50 percent lighter than the previous version, along with the carbon plate. Research suggests that the foam and carbon plate can affect the "spring like" bounce of the body as the foot strikes and leaves the ground. The shoes help to store and release energy and acts like the runner is pushing off a springboard so less energy is needed for the run.

London is considered a relatively fast course (though not as fast as Berlin) and the weather conditions was between 13-17 degrees Celsius, close to ideal.

There you have it, exceptional athlete physiology, high mileage training without injury, efficient biomechanics, super shoes , optimized fueling and favorable conditions. The recipe for success for running marathons.

Reference

Muniz-Pumares D, Hunter B, Meyler S et al (2025). The Training Intensity Distribution Of Marathon Runnersd Across Performance Levels. Sports Med. 55: 1023-1035. DOI: 10.1007/s40279-024-02137-7

Flat Feet And Overpronation

On Friday night, a patient sent me a message with pictures (above) regarding her daughter's flat feet. She was worried that it was affecting her knee, hip and lower back. Subsequently, she brought her daughter into the clinic to see me yesterday. 

Her daughter has increased her running and training more recently for her National School Games bowling competition in the first week of May. She just started having mild pain in her left foot on Friday. Because of the pain, my patient was worried about her daughter's "over" pronation. 

The readers following this blog will recall that I have written before that children from 11 months to 19 years old with flat feet are perfectly fine and do not need orthotics. You can view the Cochrane review here. 

"Over" pronation is a word that is often used by many healthcare professionals to tell their patients that it is a cause of their foot pain. However EVERYONE has to pronate when they walk or run. When you take a step forward while walking, you often land on your heels. After heel strike, the whole foot lands on the ground and this is when your foot pronates. Now imagine having insoles or orthotics to block that movement. That is what happens when you try to limit pronation.

This mechanism is very necessary otherwise no load will be distributed up the leg. In fact, it often does not cause issues in runners. And yet, patients are somehow steered and asked to avoid, limit or alter pronation at all cost.

Of course there may be occasions when you have pain in your foot or arch, and healthcare professionals may have to take the load off the area temporarily to alleviate the structures that have been irritated.

The following study by Nielsen et al (2013) published in the British Journal of Sports Medicine investigated whether newbie runners with different foot positions had more or less injuries by wearing a neutral shoe regardless of their foot type or mechanics.

The 927 newbie runners with different pronation types were followed for a period of 12 months. All the runners received the same pair of neutral running shoes regardless of whether they had neutral foot pronation or not.  

The runners accumulated a total of 163, 401 km that year. 252 runners suffered a running injury in that period. In addition, the number of injuries per 1,000 km of running was significantly lower among runners who under or over pronate than among those with neutral foot pronation.

The authors found "no risk that overpronation or underpronation can lead to running injuries through using neutral shoes for this special group of healthy beginners." The authors "compared runners with neutral foot pronation with the runners who pronate to varying degrees, and our findings suggest that overpronating runners do not have a higher risk of injury than anyone else."

The authors thought their findings were 'controversial', since it has been assumed for many years that one would risk injuries to run in shoes without the necessary support if you under or over pronate.

The study also found that the risk of injury was the same for all their runners after the first 250 km, irrespective of their pronation type. 

Note that the study did not look at what can happen if runners run in a pair of non neutral shoes nor did they investigate what runners should consider with respect to pronation and choice of shoe if they are already injured.

So as I explained to my patient and her daughter whose foot pain has gone away, that pronation or more accurately, overpronation is not to be feared.

References

Nielsen RO, Buist I, Parner T et al (2013). Foot Pronation Is Not Associated With Increased Injury Risk In Novice Runners Wearing A Neutral Shoe: A 1-Year Prospective Cohort Study. BJSM. DOI: 1136/bjsports-2013-092202.

How I Train My Breathing Muscles

My respiratory muscle trainer

Over the Easter weekend, my family and I were away in Lake Toba. Since I would be missing my regular Saturday ride, I brought along my inspiratory muscle trainer, so I could at least train my inspiratory muscles while away. I had previously written about training your breathing muscles.

I do not run with mine, just sit and breathe with it

There are different ways to train your breathing muscles. The 2 most common techniques are voluntary isocapnic hyperpnoea (VIH) and inspiratory pressure threshold loading (IPTL).

VIH involves breathing at high volumes and rates so it is similar to intense exercise while maintaining carbon dioxide at stable levels to avoid dizziness. It is primarily done using specialized devices like the Breathe Way Better device which allows you to rebreathe exhaled carbon dioxide from a bag. This creates a close loop to keep blood gas levels balanced when allowing you to strengthen your inspiratory muscles.

IPTL strengthens the breathing muscles using a device with a calibrated, spring-loaded valve like the Power Lung or the Power Breathe that requires a consistent force to open. Users breathe in forcefully through the mouth against this resistance. It creates a "threshold" that must be overcomed to be able to breathe in. That was the device that I brought along.

Where did I get this idea from? Thanks to Kowalski and colleagues (2023) who investigated 16 well trained triathletes (7 females, 9 males) for  6 weeks using the VIH or IPTL program with progressive overload. 

Both subjective and physiological responses were monitored across sessions. Blood markers, muscle oxygenation and cardiac indices were all measured before, during and after the training sessions to track adaptation and load.

The results show that both VIH and IPTL training increased physiological load. Blood gas analysis showed larger post respiratory muscle training differences in females compared to males. VIH induced smaller changes in blood gasometry compared to IPTL.

VIH produced higher subjective training load and perceived exertion compared to IPTL. IPTL caused greater metabolic stress, altering acid-base balance, elevated lactate and caused dizziness and headache.

The authors concluded that respiratory muscle training added measurable mental and physiological load in well trained triathletes. Usage of such training should be individualized depending on method and training context since this study suggests that the load (30 breaths twice a day) is significant enough to add to training load.

Even though the protocol is short and easy to fit into a training regime, my suggestion is to take it slow and use lower loads and progression to complement your regular training. 

Did it help my following Saturday ride after my Easter trip? I think it did. I fared better than I expected.

References

Kowalski T, Kasiak PS, Rebis K et al (2023). Respiratory Muscle Training Induces Additional Stress And Training Load In Well-Trained Triathletes - Randomized Controlled Trial. Frontiers in Physiology. 14: 1264265. DOI: 10.3389/fphys.2023.1264265

Farewell Physio Solutions

Thank you to our patients for supporting us through the years since we opened in 2007.

We bid goodbye to our first clinic, Physio Solutions, after 19 years at Singapore Shopping Centre. This space provided us with the opportunity to grow our patient base and train young physiotherapists. 

It gave us the space to learn how to manage a small clinic, allowing us to open a bigger second clinic in Amoy Street, 2 years later. It has been a great run and we could not have asked for more.

Will miss this room with a view

This year, when our lease came up for renewal, Gino and I decided to streamline and simplify now that we are in our 50s. We will both see our patients at our clinic in Holland Village, Sports Solutions, together with our team of physiotherapists.

Here’s to a new season of life!

To start with, it has been a nice change to be able to walk to work since April!

With the receptionists from the dental clinic next door

Being In Nature Helps

View of Lake Toba

I hope you are enjoying your Easter long weekend as you read this. My family and I are away this weekend in Lake Toba, in Medan, Indonesia

Last week, we discussed how being fit may protect us from depression and dementia. This past week I came across another article that shows how a 90 minute walk in nature also helps.

Pictures taken by walkers comparing their walks

In that study, participants who went on a 90 minute walk in nature reported lower levels of rumination. Rumination is the subjective, conscious recognition of dwelling on negative feelings, distress and their causes. It often links stress to depression and anxiety. Rumination is a know risk for mental illness.

These participants also showed reduced neural activity in an area of the brain linked to risk for mental illness compared to those who walked through an urban environment.

These results suggest that accessible areas in nature may be vital for mental health in our repidly urbanizing society.

Especially since more than 50 percent of  people live in urban areas. It is estimated that by 2050, this proportion will be 70 percent.

Not a cure-all to be in nature, but a good reminder that environment can shape mental well being. 

Reference

Bratman GN, Hamilton JP and Gross JJ (2015). Nature Experience Reduces Rumination And Subgenual Prefontal Cortex Activation. PNAS. 112(28): 8567-8572. DOI:10.1073/pnas.1510459112

That's our >90 min nature walk

Does Better Fitness Protect Us From Dementia And Depression?

I'm not a mental health expert. I only know that I always feel better after I run, cycle or do any other form of exercise. Especially if I've been particularly stressed about something or everything.

We know for sure that having good cardiorespiratory fitness is a strong indicator of overall physical  health. However, is someone with good cardiorespiratory fitness less likely to have mental health disorders or dementia later in life?

A newly published systematic review and meta-analysis provides new updates on this link across all age groups in their study (Diaz-Goni et al, 2026). 22 studies (out of 27 chosen) with 4,007,638 participants were studied in that review. 

The participants were between 18 and 64 years old, who had fitness measured at baseline and followed for 4 to 29 years. Different methods were used for measuring fitness. Some studies used VO2 max, others used indirect or submaximal exercise tests while others measured peak workload and exercise duration. Note that this paper talks about cardiorespiratory fitness and NOT about VO2 max values.

Higher cardiorespiratory fitness was associated with substantially lower future risk of depression, psychotic disorders and dementia. However it did not show to clearly help with anxiety.

Each 3.5 mL/kg/ min (or 1 MET) increase in cardiorespiratory fitness was associated with a 5 percent lower risk of depression and 19 percent lower risk of dementia.

Overall, those with higher cardiorespiratory fitness had a 36 percent lower risk of depression, 39 percent lower risk of dementia and 29 percent lower risk of psychotic disorders compared to those with lower fitness.

The authors discussed a few potential mechanisms that may explain why higher cardiorespiratory fitness helps mental or neurocognitive disorders.

From a physiological perspective, improved brain blood flow, vascular function induces structural, cellular and molecular adaptations to enhance neuroplasticity which then support cognitive and emotional regulation.

Exercise and higher cardiorespiratory fitness has been shown to help maintain the size/ volume of the hippocampus. The role of the hippocampus is linked to emotion regulation, memory and cognitive resilience. Atrophy of the hippocampus has been consistently linked to mental and cognitive disorders.

Mental health disorders and neurodegeneration are definitely complex and multifactorial. Please note that the authors also did not just conclude that "exercise is the answer". They concluded that higher cardiorespiratory fitness appears to be associated with a lower risk of several mental and neurocognitive disorders and cardiorespiratory fitness may be a useful marker to sort out groups at risk.

This is also interesting to note. Because only 1 or 2 studies were available, the authors were not able to study them as a group. Those individual studies suggested that higher fitness may be associated with lower risk of bipolar related disorders, dissociative, obsessive-compulsive and stressor-related disorders, sleep apnea as well as anxiety and ADHD in children. Depression in girls also appeared lower with higher fitness.

If the fitness influencers do pick up on this topic, I hope they do not simplify it by making it as easy as doing "some exercise or sports". 

So taken at face value, higher cardiorespiratory fitness seems to lower risk across a wide range of psychiatric and neurocognitive disorders. Do note that genetic predisposition, chronic pain, social support, smoking and diet are definitely confounding factors.

The evidence does continue to add up showing that higher cardiorespiratory fitness helps with physical disease and premature death, but also with better mental health, lower dementia risk and other mental disorders. 

Reference

Diaz-Goni V, Lopez-Gil JF, Rodriguez-Gutierrez E et al (2026). Cardiorespiratory Fitness And Risk Of Mental Disorders And Dementia: A Systematic Review And Meta-Analysis. Nat Mental Health. DOI: 10.1038/s44220-026-00599-4

New Strength Training Guidelines From ACSM

Earlier this month the American College of Sports Medicine (ACSM) revised its strength training guidelines for the first time since 2009. Needless to say there are plenty of changes after 17 years.

Especially since strength training is still treated like a recipe by many healthcare professionals. Sets, reps, rest periods, percentage of 1RM (rep max).

This new stand came from a review of 137 systematic reviews and data from more than 30,000 participants making it the most comprehensive evidenced based review on strength (or resistance) training prescription.

Strength training definitely works. It improves strength, power, hypertrophy, muscular endurance, walking speed, balance and daily tasks.

Also an update that many forms of strength training can be effective. Not just lifting weights in a gym, but also elastic bands, circuit training, home based and speed based training.

To improve strength, the evidence suggests that one needs to strength train at least 2 times a week using heavier loads. Exercise through a meaningful range of motion with 2-3 sets doing the key lifts (exercise) at the start of the session.

For hypertrophy, what matters most is doing enough work. High volume weekly, especially more than 10 sets per muscle group each week. Eccentric overload would be most effective to enhance growth.

If you are training for power, moderate loads of 20 to 70 percent of 1RM max moved fast with low to moderate volume are suggested. Olympic style lifting and power focused training seems to be most effective.

Just as interesting to note is what did not consistently matter. Time of muscle under tension, training to failure, equipment type, set structure, periodization and blood flow restriction did not consistently show improvement across the studies reviewed.

Surprised? The best strength training program is definitely not the most complex or complicated one. It is one that you can do consistently and progress reasonably and sensibly over time. And to be able to do it long term.

No need to obsess over set structure, exercise selection, home gym or public. There is no perfect strength training program, the results come from what you can do regularly over time and not what looks best on paper. Adherence is what helps you progress.

Reference

Currier BS, D'Souza AC, Singh MAF et al (2026). American College Of Sports Medicine Position Stand. Resistance Training Prescription For Muscle Function, Hypertrophy, And Physical Performance In Healthy Adults: An Overview Of Reviews. Med Sci Sports Ex. 58(4): 851-872. DOI: 10.1249/MSS.0000000000003897.

You can read the whole article here.