An Alarming Health Trend In Our Children

Picture from QMHC

I have noticed an alarming trend. Quite a few young patients I have seen in our clinic recently have hypertension (or high blood pressure). This is supported by a recent study showing that childhood hypertension rates are rising significantly around the world. 

The researchers analyzed 443, 914 young subjects aged 1-19 from 21 different countries from 96 studies. Sub-group analyses were performed by sex, age, urban versus rural settings, investigation period, BMI group. Ready for the results?

High blood pressure nearly doubled between 2000 and 2020 in children, rising from just over 3 percent to more than 6 percent. Many young children show early warning signs. Around 8 percent had blood pressure levels that suggest they may be at risk of developing hypertension in the future. 

Some children had 'masked' high blood pressure. 9 percent of children and teenagers had normal reading when tested in a clinic. They however, had higher levels when measured at home or when tested with specialized monitors suggesting that they can be overlooked.

They also found that blood pressure increased during early teenage years. Levels tend to peak at around 14 years, especially in boys. Weight plays a major role. Almost 1 in 5 children with obesity had high blood pressure compared to less than 1 in 40 children with normal weight.

This matters since the increase in blood pressure can continue when they become adults leading to a risk of heart and kidney problems. The study also highlights the fact that this condition is more common than realized and more must be done to to detect the 'masked' cases since early detection can lead to early treatment. Preventative action can be implemented in countries where childhood obesity is increasing.

Picture from Nature

The need for reliable detection, consistent measurement and effective prevention needs to standardized as high blood pressure increases among children and adolescents under 19, now that we know the scale of the problem. They are after all our future.

Reference

Zhou J, Shan S, Wu J et al (2025). Global Prevalence Of Hypertension Among Children And Adolescents Aged 19 Years Or Younger: An Updated Systematic Review And Meta-Analysis. The Lancet Child & Adoles. 10(1): 11-21. DOI: 10.1016/S2352-4642(25)00281-0

New Research On How To Heal Your Tendons

Loading both quads and Achilles tendon

We have been doing it all wrong. Yes, whatever I written previously in this blog about tendon healing is mostly outdated, except maybe this post on collagen.

We have known about this in our clinics since March this year. Having tried it myself plus teaching our patients with good results, the time is right for me to share this information.

If you have tennis or golfer's elbow pain, jumper's knee or pain in your Achilles tendon, this post will definitely interest you. Before you read further, you need to know that almost all common advise regarding tendons that we knew previously are now mostly inaccurate.

Remember Professor Keith Barr? I wrote about his gelatin collagen research back in 2019. His latest research shows us it's time to ditch outdated treatment and start using a research backed approach to healing tendons. He shared his research in an interview with Tim Ferris. You can also listen to the podcast.

Keith Barr shared that the key to tendon repair is not rest or doing eccentric exercises like we have been taught for the past 20 years. It is targeted low load isometric training.

What tendons need is mechanical load and not rest from injury. Not extreme weight to load it but gentle controlled tension to stimulate and rebuild and realign the collagen fibers correctly. Tendons do not respond well to high reps or dynamic loading especially after injury.

With chronic injuries, tendons develop strong areas to shield (or protect) the damaged areas, so longer isometric holds will make the stronger parts fatigue, redistributing load to the weaker, injured parts to be loaded and get stronger.

With isometric contractions, you are simply holding a contraction without movement, for example like a wall sit to train the quadriceps tendon. This gives the tendon just enough stimulus without wearing it out.

Loading R patella tendon and L Achilles

The effective dose to load your tendon is 10 minutes of your time, according to Dr Barr's research.  You just need to feel tension through the tendon, not necessary to be very heavy. 

Remember it's a contraction of the tendon and not a stretch. Done too long, the tendon fatigues and it's not helpful anymore. Here are the specifics. Hold the contraction for 30 seconds. Rest 2 minutes and repeat 4 times. Total of 10 minutes. You can repeat this again 6-8 hours later to make it twice a day.

The isometric holds provide the stimulus and you can help by taking collagen to help rebuild tendon tissue. Barr's recommendations to double collagen synthesis are 15 grams of hydrolyzed collagen taken with 200-250 mg of vitamin C, 30-60 mins before your isometric holds. Choose collagen from skin sources (bovine hide of fish skin) as bone can contain heavy metals.

If you're injured or have just had surgery, you can start loading immediately after injury or surgery. Dr Barr explained how patients that had correct loading 2 days after injury recovered 25 percent faster compared to those who started at 9 days after injury (Bayer et al, 2018).

Please watch the almost 2 hour video here if you want to find out more. It's really interesting. Or you can listen to the podcast on the Tim Ferris show. I listened to the whole podcast first before watching it.

Reference

Bayer M, Hoegberget-Kalisz M, Jensen M et al (2018). Role Of Tissue Perfusion, Muscle Strength Recovery And Pain In Rehabilitation After Acute Muscle Strain Injury: A Randomized Controlled Trial Comparing Early And Delayed Rehabilitation. Scand J Med Sci Sports. 28. DOI: 10.1111/sms.13269

What Equipment Causes Running Injuries?

Take your pick

Now that we are nearing the end of the year, I am seeing more runners who are preparing for the Singapore Stan Chart Marathon. Most of them are not seriously injured, just having slight niggles and wanting to fine tune their legs now that they're tapering before the race.

Others come in to discuss pacing strategies, nutritional needs during the race or whether they should be taping their muscles and joints to run more efficiently.

I came across this interesting research paper earlier this week about how running equipment that you use can predict injury in adult runners. In that study, the authors set out to investigate if runners who are using equipment while running have a higher chance of sustaining  running related injuries (RRI) compared with runners not using running equipment.

Running equipment in this study refers to insoles, ankle and knee tapes, ankle and knee braces, compression garments, jogging/ running strollers and backpack.

7347 adult runners were followed for 18 months in that study. The runners were categorized into groups that were using multiple types of equipment or expressing uncertainty about use.

51 percent (or 3713) of the runners studied sustained a RRI. The researchers found that runners who were using knee braces, knee or ankle tapes, compression socks, insoles or multiple items had higher injury rates. 

Running stroller users however were less likely to get injured. There were no meaningful associations found for ankle braces, backpacks or users uncertain about use.

The researchers concluded that certain running equipment may mean higher susceptibility to injury rather than preventing it. Running equipment should not be assumed to be protective without individual assessment or professional guidance.

This study surprisingly showed that using different types of braces and strapping did not help decrease susceptibility to running injuries. Some previous research have shown that knee braces or custom made insoles may help prevent or alleviate knee pain, ankle sprains and shin splints. Other research found that runners using insoles had nearly double the odds of RRIs compared to those not using them.

However these findings often vary due to different study designs, participant groups and types of injuries addressed. 

Perhaps a lot of new runners use them after seeing online influencers tout different types of running equipment and supplements that may help one run faster or prevent injuries. Naturally, there is still a lack of knowledge regarding the use of different types of running equipment.

It will be better for runners who are having niggles or mild running injuries to get treated for underlying training or biomechanical issues instead of using selected equipment (like tapes and braces) to prevent injuries. 

I personally think that runners using self prescribed equipment like tapes and braces may already have seen a healthcare professional for their existing pain and injuries and are using them to tide them through the recovery period to allow them to train. I have patients who have recovered from running injuries but will still tape themselves to "prevent" re-injury or simply for placebo effects.

Yes, using equipment may worsen existing problems rather than offering protection so please get a healthcare professional who can evaluate and treat the cause of your running injury or pain. That would be more effective.

Reference

Pedersen MK, Rasmussen FK, Lindman I et al (2025). Use Of Running Equipment Predicts Running-Related Injury in Adult Runners: A Cohort Study Of 7347 Runners From The Garmin-RUNSAFR Running Health Study. Trans Sp Med. 6630254. DOI: 10.1155/tsm2/6630254

Grow New Teeth?

Picture from Amazon

Last week I wrote about how consuming too much energy drinks can cause erosion in our teeth. I grind my teeth a lot when I sleep and have been using a night splint for the last 20 years. Also, I used to drink a lot more Coca Cola, sports drinks and consume energy gels back when I was competing. So I am worried about the erosion in my teeth.

If we fall and our bones break, the bones have the ability to heal and grow back. However with our teeth, the same cannot be said. Once you lose a tooth, that's it, unless you put in a dental implant to hold an artificial tooth on top.*

What if I told you now that growing back teeth may be a possibility in less than 5 years. Japanese researchers are now experimenting with an experimental drug that may regrow human teeth.

This is after years of study around Uterine sensitization-associated gene-1 (USAG-1), an antibody shown to inhibit the growth of teeth in ferrets and mice. However, back in 2021, the researchers found a monoclonal antibody (usually used in fighting cancer) that disrupted the interaction between USAG-1 and molecules known as bone morphogenetic protein or BMP. 

Suppressing USAG-1 benefits tooth growth. And believe it or not, ferrets have a similar dental characteristics to humans. Both develop 2 sets of teeth in a lifetime, a temporary set or "baby" teeth followed by a permanent adult set.

The researchers have started trials on humans. It will last 11 months and focus on 30 males between the ages of 30 and 64 with each missing at least one tooth. The drug will be administered intravenously to assess it's effectiveness and safety. Previous animal studies did not show any adverse side effects.

The researchers are hoping that if the trial goes well, they can administer this treatment to patients between the ages of 2 to 7 who are missing at least 4 teeth. The end goal will be to have tooth regrowing medicine by 2030. 

Although the current treatment will be focused on young patients with congenital tooth deficiency, the treatment will eventually be available to anyone who is missing a tooth. Human trials began last September 2024. Let's wait and see.

Reference

Murashima-Suginami A, Kiso H, Tokita Y et al (2021). Anti- USAG-1 Therapy For Tooth Regeneration Through BMP. Sci Advances. 7(7): eabf1798. DOI: 10.1126/sciadv.abf1798

* Thanks to Dr Winston Tan and Dr Dr Frank Liew who have been looking after my implants and teeth all these years.

Too Much Energy Drinks Causes Tooth Erosion

Guess what I'm drinking in my 2 water bottles in 2001?

My patient who is a dentist tells me he is seeing a lot of younger patients having erosion in their teeth.  The features of their particular erosion is non-bacterial acid induced loss of dental hard tissue. A notable contribution is due to increased consumption of acidic drinks, especially energy drinks. 

Fortunately, I never had any Red Bull or Monster in my water bottles when I was still training seriously or racing.

Like I wrote previously, energy drinks are thought to be beneficial for performance. My platoon mates in the army when we were doing national service, would frequently load up with energy drinks such as Red Bull. There was no Monster drink then. They would consume it especially in the morning before physical training and Standard Obstacle Course (SOC) training sessions. Those who were less fit tended to count on those energy drinks. One of them commented that without Red Bull he would definitely fail his fitness tests.

Some of them would also mix Red Bull with alcohol when they book out on Fridays so they can party the night away.

This was similar when I was in university. Some of my classmates did the same when cramming for an exam or writing a paper.

Energy drinks from the study

A paper published last year (Martinez et al, 2024) was investigating the pH of energy (pictured above) and pre workout/ sports drinks (below) and the consumption frequency and habits among amateur athletes. Their study analyzed the pH of 67 commercially available energy drinks and pre workout/ sports drinks. There were 43 energy drinks and 24 pre workout/ sports drinks.

Pre workout/ sports drinks

The authors also did a survey among 113 amateur athletes who completed an anonymous questionnaire to find out about the use of different beverages during various sports activities. The participants participated in strength training, endurance sports and some of them participated in both. They reported consuming energy and/ or pre workout/ sports drinks before, during or after workout.

Ready for the results? The average pH for the beverages studied was 3.3. The pH level at which enamel erosion begins is approximately 5.5, which is known as the critical pH. When the pH in our mouths drop below this level, the enamel starts to dissolve, leading to tooth decay.

51 percent of the participants surveyed said, they consumed at least one of the beverages studied. Most participants aged ≤ 29 consumed them 3-5 times each week while the older participants consumed them 1-2 times per week.

Shocked? The study showed that ALL the  energy drinks and the majority of pre workout beverages evaluated have erosive pH levels that can damage tooth enamel. Please remember this when using energy drinks or pre workout/ sports drinks. 

I always carry water with me during my bike rides instead of energy or sports drinks. Drinking plain water after your sports drinks is a good way to mitigate the erosive nature of the energy drinks. You may also want to brush your teeth when you get home.

Reference

Marthiez Lm, Lietz, LL, Tarin CC et al (2024). Analysis Of The pH Levels In Energy And Pre-Workout Beverages And Frequency Of Consumption: A Cross-Sectional Study. BMC Oral Health. 24,1082. DOI: 10.1186/s12903-024-04843-0.

Take your pick

Nose Strips Help You Race Faster?

Picture by Tim de Waele, Getty images

A patient just asked me about nasal (or nose) strips. She had seen lots of runners using them recently and wonder if they can help her run faster. 

I remember getting a couple of Breathe Right nasal strip samples in my goodie bag in a triathlon race that I took part way back in 1999. I had never used them before and I thought there's no harm in trying them in the race. 

Paula Ratcliffe in her heyday- M Hewitt, Getty images

I actually won that race but felt that the nasal strip did not help much except giving me a funny tan on my nose as race day was blistering hot. I remember seeing Jan Ullrich and Paula Radcliffe wear them when they were racing as well. 

Picture by O Docelin, Getty images

I noticed them again during the Tour De France this year (pictured above). Many cyclists were seen using them, some even using custom decorated ones. 

Bastille Day -Tim de Waele, Getty Images

So are these nose strips worth wearing? Do they help improve your sporting performance? Yes they do help with the "negative pressure" that builds up and blocks your nostrils during heavy breathing. They do improve airflow by enlarging your breathing passageway. 

However, what really matters is the amount of oxygen that gets into your bloodstream and not the amount of air you breathe in. For most people, the normal air you breathe in will mostly saturate your blood's oxygen carrying capacity.

A recent systematic review concluded that nasal strips do not help with VO2 max, rates of perceived exertion or heart rate response (the body's response to exercise).

If you're eating an energy bar on the bike or run, the nasal strip can help increase the ease of eating and trying to breathe at the same time. They can increase the comfort of breathing, especially if you have a deviated septum, some nose congestion or allergies, but they do not offer a performance advantage.

There is no real 'downside' and at best a placebo effect for those using them. I personally think it is more of a fashion statement if you look at the pictures from the 2025 TDF.

Should you try the nose strips? Yes, if you suffer from specific nose structure issues or want to use them as a fashion statement. They are not expensive and a good placebo effect is a legal performance enhancer.

References

Dinardi RR, Ferreira CHS, Silverira GS et al (2021). Does The External Nasal Dilator Strip Help In Sports Activity? A Systematic Review And Meta-Analysis. Eur Arch Otorhino. 278(5): 1307-1320. DOI: 1007/s00405-020-06202-5.

Illidi CR, Romer LM, Johnson MA et al (2023). Distinguishing Science From Pseudoscience In Commercial Respiratory Interventions: An Evidence-based Guide For Health And Exercise Professionals. Eur J Appl Physiol. 123(8): 1599-1625. DOI: 10.1007/s00421-023-05166-8

No Need To Cool Down After Exercise?

Athletes, coaches and physical education teachers have always been told that an active cool down is more effective for promoting post exercise recovery than a passive cool down (no activity). This is assumed to allow for individuals to perform better during subsequent training sessions or competition and perhaps even lower the risk of injury. 

However, there is not much research on whether the above is true. I've written previously how it may be unnecessary to cool down after exercise. What if I say that in some cases an active cool down may even be harmful?

The most widely used post recovery exercise intervention is probably the active cool down. It is commonly referred to as the 'warm down'. This is usually a 5 to 15 minutes of low to moderate intensity exercises after exercise/ competition. Some will do a slow jog, cyclists often ride easy on the bike while it's attached to a stationary trainer.

The following review by Van Hooren and Peake (2018) compares the effects of various types of active cool downs with passive cool downs on sports performance, injuries, long term adaptive responses and markers of post exercise recovery.

Ready for the summary? 

The review shows that an active cool down helps lead to faster removal of lactate in blood. However the practical relevance of this finding is questionable since lactate is not necessarily removed faster from muscles. 

An active cool down can partially prevent the depression of circulating immune cell counts after exercise, although it is unknown if this leads to fewer infections and illnesses.

An active cool down can definitely result in a faster recovery of the cardiovascular and respiratory system after exercise/ competition, but it remains unknown if this reduces post exercise fainting and cardiovascular complications.

Active cool downs does NOT significantly reduce delayed onset of muscle soreness (DOMs) or improve the recovery of indirect markers of muscle damage. It does not significantly alter the recovery of neuromuscular and contractile properties of muscles, it does not improve range of motion of muscles, and does not reduce musculotendinous stiffness following exercise. It may even interfere with glycogen synthesis.

The review also provided evidence that an active cool down generally does not improve and may even negatively affect performance if the time between successive training sessions or competition is > 4 hours.

An active cool down also has no substantial effects on next day(s) sports performance although some beneficial effects have been reported. They do not prevent injuries and preliminary evidence suggests that performing regular cool downs do not reduce the long term adaptive response.

However, most individuals perceive an active cool down as being more beneficial than a passive cool down. The effectiveness of an active cool down may differ depending on each individual's preferences and beliefs. Some athletes may benefit more from an active cool down while others may prefer to perform no cool down at all.

Some general guidelines for those who still wish to perform an active cool down. It should involve aerobic activities performed at low to moderate intensities to increase blood flow, but prevent development of substantial additional fatigue. 

It should involve low to moderate impact to prevent additional muscular damage or DOMs. It should be shorter than 30 minutes to prevent substantial interference with glycogen resynthesis. So make sure you eat/ drink quickly after exercise or competition. 

Some evidence also suggest that an active cool down should involve the same muscles used in the preceding activity. Now you know.

Reference

Van Hooren B, Peake JM (2018). DO We Need A Cool-Down After Exercise? A Narrative Review Of The Psychophysiological Effects And The Effects On Performance, Injuries And The Long-Term Adaptive Response. Sports Med. 48:1575-1595. DOI: 10.1007/s40279-018-0916-2

Cycling Helps Prevent Dementia?

Riding towards the sun

My laptop could not connect to the hotel WIFI network last weekend when I was away, so I'm only posting last week's post now.

Many of you reading this will know that on the Saturdays that I'm not traveling, I do a long bike ride with my usual cycling group. Since I was away, I also missed my Saturday bike ride.

I may have missed my Saturday ride, but I did get to read a very interesting article on cycling. Researchers found that sustained aerobic exercises (like cycling) may reduce the risk of dementia (Hou et al, 2025).

There were 479, 723 participants ( 260,730 females, 54.4 percent) with a mean age of 56.5 years in that study. These data were collected from the UK Biobank with the aim to investigate the long-term association between travel modes and dementia risk and to evaluate whether genetic predisposition can modify the association between travel modes and dementia risk.

To understand the link between brain health and common forms of travel, the participants were asked if they usually used motor vehicles, walking, cycling or public transport.

The researchers found that participants that cycled regularly (not including commuting to work) had a lower risk of developing dementia compared to those who walked, drove or used public transport. They were 19 percent less likely to develop all-cause dementia and 22 percent less likely to develop Alzheimer's disease.

The authors suggest that "this likely stems from cycling's higher aerobic intensity and cognitive engagement (e.g. navigation, coordination), which may enhance neuroplasticity more than walking alone". Other than regular exposure to fresh air from cycling, the physical demands of cycling plus the need to stay alert whilst on the roads or trails may help to maintain brain health.

This is supported by other studies (Erickson et al, 2011) where cycling or other aerobic exercises causes the hippocampus, the part of the brain responsible for memory formation, learning and spatial navigation to grow. Note that typically, the hippocampus reduces in size during late adulthood (from the mid to late 60's).

The authors concluded that the findings "suggest that promoting active travel strategies, particularly cycling, may be associated with lower dementia risk among middle-aged and older adults, which carries substantial public health benefits".

Now, that's a very good reason to keep cycling. Let's make our roads safer for cycling.

References

Erickson KI, Voss MW, Prakash RS et al (2011). Exercise Training Increases Size Of Hippocampus And improves Momory. ProNatl Acad Sci USA. 10897): 3017-3022. DOI: 10.1073/pnas.1015950108

Hou C, Zhang Y, Zhao F et al (2025). Active Travel Mode And Incident Dementia And Brain Structure. JAMA Netw Open. 8(6): e2514316. DOI: jamanetworkopen.2025.14316

Time Of The Day When You Are At Your Best

Picture from Healthyplace.com

I have been out of school for decades and have not sat for any tests or exams in quite a while. But I do see new patients almost every day I am working in our clinics. I do take plenty of "tests" too, since every single patient I see will evaluate my treatment and decide if I made them better.

You must be wondering why I am writing about tests this week, Well, the Singapore primary school leaving exams (PSLE) just ended this past week.  Parents whose children just sat for the exams must heave a collective sigh of relief now that it's all over. 

The typical start times for the PSLE oral exams are at 0800 while written exams generally commence at 0815 hours. That's definitely an early start for those taking exams.

Unlike the students sitting for exams, we usually see new patients in our clinic whenever we can fit them in for an appointment. This may not necessarily be the best according to a group of researchers who analyzed the results of over 100,000 oral exams. They found a clear Gaussian distribution (also know as the Normal distribution or bell curve) in pass rates that peaked at noon. 

Passing rate by hour 

Between 11 am and 1 pm is the best time (pictured above). Any earlier or later the chances of passing significantly decreased. In fact the earlier or later in the day these students took a test, the less likely they were to pass.

The reason being our cognitive (or conscious intellectual ability) performance improves over the course of the morning and then declines in the afternoon. We also may have declining energy levels later in the afternoon. If your exam is scheduled later in the day, you may also stress about it and this usually leads to poorer performance.

According to the author's, the examiner's cognitive performance and fatigue level also matters. Both the examiner and student will be at their peak level of performance during the mid day hours.

This all means that whenever possible if you have to take a test or exam, an important meeting or a job interview, you should schedule it between 11 am and 1 pm. It can be the difference between passing and failing. 

Perhaps we should only see new patients in our clinics between 11 am and 1 pm then. 

Reference

Vicario CM, Nitsche MA, Lucifora C et al (2025). Timing Matters! Academic Assessment Changes Throughout The Day. Frontiers Psychol. 16:1605041. DOI: 10.3389/fpsyg.1605041

Training In Hot Conditions Makes You Eat More?

Just after sunrise

After all the rainy days during the first 2 weeks of September, the temperatures were nice and cool. This past week it seems like "someone turned the tap off" and it's been way hotter. 

I weighed myself yesterday morning before and after my regular Saturday ride before work and found that I had lost 2 kg (mostly water) despite eating and drinking more during the ride. These 3 hour rides, when warmer, make me feel like I'm making my body work double time. I've noticed that when the temperature is higher, I need to eat more (during the ride) or else I cannot keep up with my friends.

On Saturday rides that are cooler, I sometimes don't even eat the banana that I bring with me and can still ride well without tiring.

Turns out that training in Singapore's heat and humidity does not just make one more comfortable in hot conditions, it actually changes how our muscles use energy (Xu et al, 2025).

The authors in the study quoted above show that a month of structured heat acclimation training can help change your metabolism to race stronger when it's hot and probably in cooler temperatures too.

The researchers split 18 trained middle and long distance runners into 2 groups. Both groups completed treadmill tests and metabolic assessments at temperatures of 30-32 °C (or 86-89 °F).

The first group trained in normal temperatures (20-25 °Celsius or 68-77 °F). The other group did 20 sessions of heat acclimation over 4 weeks. They ran in tem[eratures between 30-36 °C that pushed their core temperatures to 39-40 °C (or 102-104 °F).

No prizes for guessing that the heat acclimated group made more notable adaptations compared to the control group. Their core temperature during the subsequent treadmill test was lower by 0.4 °C, a clear sign of improved thermoregulation. They were also more efficient aerobically, as oxygen uptake improved by 4 and 3.7 percent at the *first and second ventilatory thresholds.

Plasma volume improved by 4 percent, haemoglobin by 2 percent and erythropoietin by 13 percent after heat acclimation, showing better oxygen support. All signs of heat adaptation.

At submaximal intensities (75 and 85 percent VO2 max, carbohydrate oxidation dropped by 15-19 percent in the heat acclimated group. The runners used less blood glucose and muscle glycogen, using more of the body fat instead. Exactly like I wrote above when I do not need to eat as much during cooler rides. In the picture above, carbohydrate (CHO) use and energy expenditure (EE) before and after control (black bars) and heat training (red).

Upon finishing the treadmill test, the heat acclimated runners cleared lactate more efficiently demonstrating improved recovery.

However, VO2 max did not change, suggesting that having a higher VO2 max (compared to someone else) may not mean you will race faster. The efficiency gains were more beneficial.

Take home message? Those of us who live in sunny and super humid Singapore can train almost all year round in such conditions. A 4 week block of 5 days a week may give you the metabolic edge of using less carbohydrates at higher intensities. This spares your glycogen stores and delays fatigue. The thermoregulatory and blood adaptations will help you stay cooler and deliver oxygen more effectively, especially if you are going to be racing in a friendlier climate. 

You will need to monitor the above parameters and allow for adequate recovery to get the benefits. This is when your blood, sweat (lots of it) and tears will pay off if you do it correctly.

Reference

Xu Y, Ye C, Ma S et al (2025). Four-Week Heat Acclimation Lowers Carbohydrate Oxidation Of Trained Runners During Submaximal Exercise In The Heat. Frontal Physiol. DOI: 10.3389/fphys.2025.1581594/full

*First ventilatory threshold (VT1) is when your breathing becomes noticeably deeper and lactate starts to accumulate in the blood. This indicates a shift from using mostly fat to carbohydrate during exercise.

VT2 or second ventilatory threshold occurs later, this is often when breathing is rapid, more labored leading to a sharp increase in carbon dioxide production. This is when a significant shift to anaerobic metabolism.

Still not too hot

How to Run Faster At The Boston Marathon

Picture from Runnersworld.com

I came across a recently published article detailing the training of 917 runners (495 women, 422 men) who qualified and ran in the 2022 Boston marathon (Lempke et al, 2025). The majority of them finishing in mid-3 hour marathon times. So definitely relevant insights for most serious recreational runners if you want faster marathon timings.

This interesting new study tracked running duration, volume, cross training and changes in training frequency between the last 12 months to 4 months before the race day. Yes, you read correctly, the runners were training 12 months in advance before racing. In addition, training intensity distribution like steady state runs, quality sessions and interval sessions were also analyzed.

Let me highlight the relevant findings. The study found that those who had longer running durations, higher quality ('hard') sessions, running distance and/or volume from 12 months to 4 months before the race was consistently linked to faster timings.

From 12 months to 4 months before the race, those who ran more than 10 hours weekly predicted significantly better performance than 5-7.5 hours, 2.5-5 hours and less than 2.5 hours per week of training (pictured above). For reference, the weekly mileage for the 495 women studied ran 64.4 ± 24 each week while the 422 men studied ran 67.6 ± 26.2 km on average.

Each extra run shaved 3-4 minutes off race time, while each extra quality session was worth 16-17 minutes better timing on average. Running an extra 1 km a week was worth about 3-4 minutes off marathon time.

In the final 4 months to race day, all of the above variables predicted better performance. Runners who included cross training in the final 4 months ran significantly better. Each extra session per week translated to being faster by 6 minutes of finishing time.

Reducing running frequency in the final 4 months improved performance. The runners who decreased their total weekly running sessions averaged 3 minutes faster than those who maintained or increased the frequency of their running sessions.

Just in case you got confused reading the above (I did at first) where the study said adding an extra run each week helps in the final 4 months, but also said a reduction in frequency was associated with better performance (pictured above). 

This means that between 2 runners, the runner running 5 times a week would be faster than another runner running 3 times a week. However, a runner who reduced their runs by 2 runs a week would run faster than another runner who only reduced their runs by 1.

Note that this study was survey based and depended on what the runners recorded in their training logs. Most runners tend to be meticulous about this, I know I was. There was also no mention of what the runners did for cross training. In addition to cycling or deep water running, I also did strength training.

Reference

DeJong Lempke AF, Ackerman KE, Stellingwerrff T et al (2025). Training Volume And Training Frequency Changes Associated With Boston Marathon Race Performance. Sports Med. DOI: 10.1007/s4027-025-02304-4

Rivals Or Brotherly Love

CL and I were rivals (actually more of a team mate as we were friends too) on the track when I was competing in my secondary school's track and field meet. We competed in the 800m, 1500m, 3000m and the 2000m steeplechase events. Though I won all 4 events, knowing CL was also training hard was a powerful motivator and it pushed us both to be better runners.

Yes, having a rivalry with a colleague, friend, or even your sibling can be stressful, but the right kind of competition will elevate each other's performance.

Carlos Alcaraz and Jannick Sinner are currently the top 2 tennis players in the world. They faced each other in 3 of the 4 Grand Slam finals this year including the recently concluded US Open where Alcaraz won. They currently have a super rivalry and their duels definitely push each one to higher heights. Just like Rafael Nadal and Roger Federer (pictured above) before them.

Research has shown that rivalries can have perks. One study showed that runners ran almost 5 seconds faster per kilometre in a race when a runner whom they considered a rival was also racing.

Another study showed that when different NCAA, NFL, NBA, and MLB team performances were analyzed, when a team's rival beat them in the post season one year, that same team does better the next year.

Of course there are occasions when rivalries can hurt us. One study showed that people can be unethical or even ruthless when competing against a rival because they really want to win.

A big difference between rivalries that boost us versus those that hurt us is whether they are viewed as long term relationships. Nadal and Federer are real friends after they step off the court after trying their hardest to beat each other on court. Federer wrote a moving tribute to Nadal just before his last tournament. Nadal did the same for Federer just before the latter retired too in 2022. 

It appears that Alcaraz and Sinner too have an underlying friendship besides their rivalry.

Picture from Cyclinguptodate.com

This is very much like what currently happens in cycling too. Current world cycling champion and 4 times Tour De France winner Tadej Pogacar is very friendly with his rivals, even driving to a race (Milan San Remo) together. 

Pogacar and Vingegaard

This was highlighted in a viral podcast by Lance Armstrong. Some cyclists may agree with Lance, but it's probably the character of Pogacar, Mathieu van der Poel and Jonas Vingegaard etc to be friendly and get along. That is definitely acceptable and touching even.

So, you do not have to be buddies with your rival, but surely you can be friends and have mutual respect for each other. Wish each other well and do your best to beat the other and this may help both of you soar to higher heights.

References

Kilduff GJ (2014). Driven To Win: Rivalry, Motivation And Performance, Soc Pysch Per Sci. 5(8): 944-952. DOI: 10.1177/1948550614539770

Kilduff, GJ,  Galinsky AD, Gallo E et al (2016). Whatever It Takes To Win: Rivalry Increases Unethical Behaviour. A Manag J. 59(5): 1508-1534. http://www.jstor.org/stable/26157371

Pike BR, Kilduff GJ & Galinsky AD (2018). The Long Shadow Of Rivalry: Rivalry Motivates Performance Today And Tomorrow. Psych Sci. 29(5): 804-813. DOI: 10.1177/0956797617744796

Girls Get A Lot More Anxious Than Boys

Picture from Motherwellmag

In a first of its kind study, Prof Setoh and colleagues from Nanyang Technological University found that girls are a lot more anxious than boys. This happens between the ages of 8.5 and 13 years when they go through a sharp spike in social anxiety. They fear being judged negatively in social situations.

By the time they turn 13, their social anxiety levels are significantly higher than boys. If untreated, this may lead to poor mental health and interpersonal relationships. Academic and work performance later in life may be affected as well.

The article was just published on 300825 in the Research On Child And Adolescent Psychopathology. The Straits Times also published an article on it on 010925.

ST 010725

You must be wondering why I chose this topic this week, or wondering about my credentials on adolescent mental health. 

Just after I came across the newspaper article, I remembered a recent study by Lundgren et al  (2025) on how physical activity during certain periods can protect children from developing depression, anxiety and addiction. Their study was based on a large group of Swedish children followed from birth until their 18th birthdays. The long time frame allowed comparison between parent-rated levels of activity to diagnoses from a national registry. This is to eliminate pre existing issues that caused low activity levels or transient dips that were interpreted as social anxiety issues.

The study involved 17,055 children, who were born between 1997-1999. The parents had to rate various aspects of their child's health at 5, 8 and 11 years. Activity levels were tracked separately for school days and non school days. Participation in organized sports were tracked at 11 years and reported in hours per week.

The authors found that physical activity (reported by parents) declined from 4.2 to 2.5 hours each day between 5 and 11 years of age. Analyses showed that boys and girls had different outcomes and patterns. 

Time outdoors showed no protective associations while participation in organized sports at 11 years of age showed significant protective effects on anxiety and addiction for both boys and girls and on depression for boys. The authors concluded that his study provides evidence that physical activity and participation in organized sports may have protective effects against several adolescent mental health diseases.

Possibly policymakers working to control vaping in Singapore could use this information?

Access to the articles at the links below.

References

Lundgren O, Tigerstrand H, Lebena A et al (2025)Impact Of Physical Activity On The Incidence Of Psychiatric Conditions During Childhood: A longitudinal Swedish Birth Cohort Study. BJSM. 1:59(14): 1001-1009. DOI: 10.1136/bjsports-2024-108148

Tng GY, Law ECChen HY et al (2025). Developmental Trajectories Of AnxietySubtypes From ChildTo Early Adolescence: The Role Of Parenting practices And Maternal Distress. Res Ch Adoles Pysch. DOI: 10.1007/s10802-025-01364-4 

Can Too Much Running Increase Colon Cancer Risk?

Just when I'm reading about Ultras

If you've read a previous post of mine you know that there is evidence showing that people who are physically active have a lower incidence of cancer. A 2016 meta-analysis of 52 prospective studies found physically active adults were 24 percent less likely to have colon cancer compared to sedentary peers.

So I was very surprised when I came across a poster presentation that suggested that those who do high volume ultra marathon and marathon running may actually have an increased risk of advanced pre-cancerous colon lesions. The New York Times wrote about this too.

Researchers had 100 long distance runners ranging from 35 to 50 years who completed at least 2 ultramarathons (> than 50 km) or 5 marathons. These runners underwent screening colonoscopies, with all polyps reviewed by a team of oncologists, pathologists and gastroenterologists. 

They were found to have polyps (> 10mm with  tubulovillous features) that were more likely to turn into cancer compared to the general population (40-49 years old). 15 percent of the 100 runners had advanced adenomas. This was greater than 10 times higher than the benchmark. 39 runners had at least 1 adenoma of any type.  Prevalence in the matched general population was just 1.2 percent.

Most cases happened in runners with very high training exposure (pictured above), multiple ultramarathons or completed more than 15 races. There were even a few cases of high grade dysplasia, just 1 step away from colorectal cancer.

The researchers' hypothesis was that due to extremely high volume distance running, this leads to repeated low blood flow to the gut leading to chronic injury and inflammation. This can repeatedly injure the stomach lining. This recurring pattern may then accelerate carcinogenic changes that lead to the development of pre-cancerous adenomas.

Moderate exercise does lower systemic inflammation, but ultra marathon training can increase inflammation in the gut made worse with frequent high volume racing. This worsens during intense exercise in the heat. Since chronic gastrointestinal stress impairs absorption of fibre and micronutrients that normally protects the colon, their findings may be reasonable. More so if recovery isn't adequate.

The difference compared to the normal population does cause some concern. However, do note that this is a relatively small study done only in 1 location. There is no proof of causation, genetics, nutrition and other lifestyle factors that may also play a role. 

For most of us runners, running is protective against colon cancer, and does not increase our risk to it. I do not have any patients who run >2 ultra marathons or more than 5 marathons a year. If they do, then their risk profile may (emphasis on may) be higher. 

So if you do log mega mileage, race often and are concerned about your cancer risk, it may be wise to get colon cancer screening particularly if you have persistent gastrointestinal symptoms.

Do wait for the full peer review study to be published before making any final conclusions.

Reference (for the abstract)

Cannon TL, Bonomelli S, SwainWR et al 92025). Risk Of Pre-Cancerous Advanced Adenomas Of The Colon In Long Distance Runners. J Clin Oncology. 2025 ASCO Annual Meeting. 43(16) suppl. DOI: 10.1200/JC0.2025.43.16_suppl.3619