Sural Nerve Pain

I recently saw a patient who had pain resulting from her sural nerve. Let me go through a little about the anatomy and location of the sural nerve.

The sural nerve sits superficially below the skin's surface at the back of the calf. It is formed from the medial sural cutaneous nerve and the lateral sural cutaneous nerve.

It is usually between the medial and lateral gastrocnemius (calf) muscles, running parallel to the saphaenous vein. At the ankle, the sural nerve 'wraps' around the outer ankle near the peroneal tendons before it splits into 2 branches at the level of the 5th metatarsal.

The sural nerve is a sensory nerve, it provides sensation to the lower one third of the outer leg, outer heel and foot. It's main function is to let you feel sensation on your skin. It can also detect your foot position, temperature, pain, vibration and touch.

Since the sural nerve is positioned so superficially, it can be irritated from any muscular of fascial entrapment and sometimes from a simple outer ankle sprain. It can also be 'over stretched' from sitting too long with the foot pointed down and out or after a long driving trip. When the nerve is irritated, it can result in burning pain in the lateral shin or foot (known as sural neuritis).

A common cause of sural nerve pain is after a sprained ankle when the foot is rolled outwards quickly. This can over stretch the sural nerve causing pain over the area it covers. 

I also remember a previous patient who had very tight fitting ballet shoes with a strap over the outside ankle which compressed her sural nerve.

A lot of metal work

Another patient had irritation from her metal implants (pictured above) after orthopaedic surgery from fracturing both tibia and fibular. 

Patients may describe their pain being constantly present, made worse with activity but present even at rest. This constant pain at rest is what differentiates the symptoms of sural nerve pain from other conditions, where pain normally eases with rest.

I usually do a modified Straight Leg Raise tension test to compare both sides. The patient will tell you the affected side will worsen their symptoms. It may also be tender to touch along the path of the nerve.

Appropriate manual therapy will easily relieve and treat sural nerve pain. Mobilizing the ankle, stretching the nerve and of course treating the fascia that is putting tension on the sural nerve. 

Hot Water (Not Cold) Immersions More Effective For Recovery

Picture from Racold.com

With the Paris Olympics around the corner, many of my patients have been asking me about recovery, ice immersions and the Singapore women's swimming Olympic selection fiasco (no, I am not discussing that).  

A patient I saw yesterday mentioned that an ice immersion recovery center just opened near his home and he was hoping it will help his sore muscles.

Picture from Business Insider by Alexandre Simoes 

I told him that evidence shows that ice baths/ immersions does not help  recovery. In fact cold water immersion after hard exercise suppressed signaling pathways associated with recovery. This suppression lasted several days. In addition, ice bathing reduced the body's muscles uptake of dietary proteins, which is important for growth and cell maintenance. Grgic (2022) showed that cold water immersion reduced exercise related strength gains while (Pinero et al, 2024) showed that ice bathing immediately after weight training inhibited muscle growth.

On the contrary, hot water immersion (below) improved recovery follwing exercise induced muscle damage (Sautillet et al, 2024).

Picture from Newsmeter

Following exercise induced muscle damage, Sautillet and colleagues (2024) put 30 active males through one of the following recovery interventions : cold water immersion (11 degrees Celcius), hot water immersion (41 deg Celsius) and control group of warm-bath (36 deg Celcius).

Quadriceps maximum strength and explosive strength were measured pre, 24 and 48 hours post exercise. Pressure pain threshold (PPT), or was also measured to quantify the recovery from muscle soreness

Here are the results. 48 hours post exercise, quadriceps maximal strength returned to baseline values after both cold and hot water immersions. However, explosive strength levels and PPT (muscle tenderness) returned to baseline levels post 48 hours only after hot water immersion.

In addition, surface electromyography (electrodes) signals from the vastus lateralis (outer quadriceps) was significantly increased following cold water immersion. Meaning more muscle fatigue. Or as patients like to say, their muscles are 'very tight'.

The authors concluded that a single session of hot water immersion (rather than cold water immersion) improved the rate of explosive strength followed exercise induced damage. When explosive power is a key performance requirement, hot water immersion should be preferred over cold.

*Note that the cold bath temperature used in this study (Santillet et al, 2024) was 11 degrees Celcius. Wim Hof (the Dutch iceman), others on Tik Tok, other social media and purveyors of commercial health and wellness have different protocols.

For those who are keen the temperature of the hot bath was 41 degrees Celsius for a duration of 15-30 minutes.

References

Grgic J. (2023). Effects Of post-exercise Cold-water Immersion On Resistance Training-Induced Gains In Muscular Strength: A Meta-analysis. Eur J Sp Sci. 23(3): 372-308. DOI: 10.1080/17461391.2022.2033851.

Pinero A, Burke R, Augustin F et al (2024). Throwing Cold Water On Muscle Growth: A Systematic Review With Meta-analysis Of The Effects Of Postexercise Cold Water Immersion On Resistance Training-induced Hypertrophy. Eur J Sp Sci. 24: 177-189. DOI: 10.1002/ejsc.12074

Sautillet B, Bourdillon N, Millet GP et al (2024). Hot Bt Not Cold Water Immersion Mitigates The Decline In Rate Of Force Development Following Exercise-Induced Muscle Damage. Med Sci Sp Ex. DOI: 10.1249/MSS.0000000000003513

Can Ozempic And Wegovy Help Knee Osteoarthritis Pain?

Picture from Second Nature 

I never thought I would be reading up on Ozempic and Wegovy. I have a patient who told me he started taking Ozempic as he's trying to lose weight. They are both injected medications that contain semaglutide. Ozempic is approved (in USA) to treat Type II diabetes while Wegovy is a higher dosed version (of semaglutide) that is approved (again in USA) for weight loss.

According to results from the STEP-9 trial (by Novo Nordisk) reported at the World Congress on Osteoarthritis (OARSI 2024), Wegovy, containing peptide receptor agonist (GLP-1) semaglutide not only induced weight loss but improved knee pain in people with knee osteoarthritis (OA).

STEP-9 was a multi national, multi center phase 3 clinical trial that enrolled subjects that had a BMI of >30, a clinical diagnosis of knee osteoarthritis with moderate radiographic changes and were experiencing knee pain.

There were 407 subjects in STEP-9, randomly allocated 2:1 to receive once a week a subcutaneous injection of either semaglutide 2.4 mg or a placebo for a total of 68 weeks. Mean age of the subjects were 56 years and 81.6 percent were women. 60.9 percent were White, 11.8 percent Native American, 7.6 percent Black and 19.7 percent were of other ethnic origin.

Another finding was that the use of pain medication went down in the semaglutide group compared to the placebo group. This was maintained throughout the study.

Of course the are suggestions that the weight loss itself helped with the knee pain since weight loss fell by a significantly greater amount in the people treated with semaglutide versus those given a placebo. Weight loss was 13.7 percent versus 3.2 percent from baseline after 68 weeks.

The authors questioned if there is a specific action of GLP-1 receptor agonist on the knee joint itself and not through weight loss only. Especially since results from previous LOSEIT trial using liraglutide (also used to treat Type II diabetes) showed that subjects lost 2.8 kg versus a gain of 1.2 kg in the placebo group over a year did not have any change in the Knee injury and Osteoarthritis Outcome scores. The patients in that study had to undergo weight loss first before they were given the liraglutide.

Obesity is a worsening problem world wide in developed countries and Singapore has increasing numbers in people with diabetes. This is certainly going to add to the boom in weight loss drugs.

Morgan Stanley projects that the market for weight loss drugs will reach $54 billion by 2030, a 400 percent increase from today. Especially since so many celebrities have gushed about how much weight they have lost since taking them. Eli Lilly and Novo Nordisk (who owns Wegovy and Ozempic) together have at least 12 more obesity medications under development.

We are living through a cultural shift in which obesity is viewed as a disease rather than the result of lifestyle choices. 

Should my patient try Wegovy instead especially since he does have knee pain from osteoarthritis? Wegovy has a higher dose of 2.4 mg semaglutide versus 2 mg for Ozempic.

Will Wegovy or Ozempic be the new default recommended treatment for osteoarthritis pain instead of surgery, gel injections and physiotherapy?

Reference

https://www.medscape.com/viewcollection/37518

*Please note that the STEP-9 study was funded by Nova Nordisk and the principal investigator Henning Bliddal acknowledged that research grants were given by Novo Nordisk to his institution as well as consulting fees and honoraria. He also received congress and travel support from Contura

Inspired Or Pissed?

I am sure most track and field fans have been following the ongoing USA Olympic Trials. Leading up to the trials, there was a fair bit of of discussion about 1500m runner Eric Holt.

Holt (who is 29) ran his fastest 1500m race at the New York City Grand Prix on 8-9 June, finishing 2nd behind Jake Whitman, the 2022 world champion. 

He was interviewed after the race and unlike many other runners he had no sponsorship, calling himself an amateur. He pays for his own running gear and physiotherapy sessions.  That interview led to an article about him in the Washington Post. He worked 13 hour shifts in a psych ward to make ends meet, where he prevents patients from harming themselves. The running team he trains with found him when he posted his extremely hard workouts on Strava between 11 pm and midnight.

Besides living with his parents (which he was feeling embarrased about), his girlfriend also pays for their meals when they do go out. He dreams to be a professional runner and promises to return the favor if he gets sponsored. He wants to prove to sponsors that he is hard working and talented, and that he's not some schmuck (foolish).    

He ends the interview by saying that he's gambling and betting his life, sacrificing everything to be a pro one day.

I thought that was really inspiring since I ran cross-country and track and field in seconday school and can identify with Holt. However, there were other running fans who saw the same interview but had a much different view. 

You can watch a profanity laced video of another track fan berating Holt for his 'sob' story. He thinks Holt should quit running and get another job. He even criticized people like me who would encourage athletes like Holt.

If you watched the critique video, please share your reaction in the comments. There is no right or wrong answer, I am just curious to hear your views.

Today is the last day of the trials. Sadly, Holt did not qualify for both the 800m or the 1500m, but at least he got Puma as a shoe sponsor now.

Thank you for reading and thanks in advance if you share your thoughts in the comments.

Rehab Is Like Snakes And Ladders

I am currently treating a few patients after they have had surgery. A patient with knee partial menisectomy and microfracture surgery, 2 with back surgery and 3 with ankle fractures that needed pins, rods and plates for stabilization.

All of them had some form of setback whilst recuperating. Kind of like playing snakes and ladders. Often we are very eager to roll a 6 on the dice and get a quick ride up the longest ladder on the board. We all want some shortcuts to win and in their cases get back to full training/ competition or living a 'normal' life as quickly as possible.

However, lurking near those big ladders are the big snakes that can send you all the way back down to the lowest level on the board.

That's the risk you take and 'punishment' associated with trying to go too fast with rehab and taking shortcuts. Short term gain often leads to frustration and long term failure.

Granted there are those who will, on occasion, roll lot's of 6's, goes quickly up the long ladders while avoiding the snakes and win. They are very rare though and that should not be our strategy when we start rehabilitation after surgery.

What's the best game plan? Rolling 3's and 4's steadily and steadily make our way up the board. If you get a big ladder great, if not a small one helps or even a small snake. These little wins and losses are not too beneficial nor too detrimental to the overall recovery plan. You will eventually get to the top of the board.

So, do not be seduced by the long ladders because there is always a bigger snake ready to take you all the way back down if you start to gamble on quick fixes over the steady approach.

Slow and steady is the way to do it. You will eventually get to the top of the board.

Does Eating Just Before Sleeping Make You Fat?

My elder son (pictured above) is on a muscle building spree. He's been trying to strength train while eating lots of protein. I've also mentioned to him that consuming protein right before sleeping would lead to greater improvements in muscle strength and muscle size. 

When he was 9 in 2019

He then mentioned that he had watched videos on Tik Tok that suggested that eating just before sleeping will make one fat. 

Is that what you think too? That eating before sleep makes you accumulate fat because you are resting for many hours after you eat. Well, let me show you that this is untrue. Note that this is with pre-sleep protein consumption. 

Data from men and women show that consuming protein pre-sleep does not change overnight fat metabolism (breakdown of fats to be used as energy). When research participants consume either caesin protein (found in milk, cheese and yoghurt) or a non caloric placebo, there was zero difference in the overnight fuel use or energy expenditure. There was also no difference in the amount of fat liberated from the fat cell measured with a technique called microdialysis.

This may be a big surprise to you as it is often thought that eating before bed will inhibit fat metabolism. Now you know it is not true. Protein consumption helps improve strength, recover from strenuous exercise as well as maintain and improve metabolic and structural health. Evidence suggests that the average person should consume 1.2 grams of protein per kilogram of body weight per day. Athletes should consume closer to 2 grams per kilogram of body weight.

Pre-sleep protein has also been found to decrease next morning hunger. Adequate protein consumption also promotes satiety, leading to a reduction in over-eating.

Plant protein my son consumes

What type of protein should you eat before bed? Recent literature suggest no difference in muscle recovery after pre-sleep consumption of dairy/ animal or plant-based (rice/pea) combination as long as enough of each is consumed. It also comes down to dietary preference. Most of the earlier research used whey or casein proteins due to a high leucine (thought to trigger growth) content. 

Whey and casein protein were more popular previously due to their ease of digestion and availability. Especially since plant based protein were not so easily available then and they cost more. Most pre-sleep protein research uses casein followed by whey protein since plant-based protein has less leucine. A greater amount of plant-based protein is needed to be consumed to elicit the same response compared to a lower amount of animal-based protein.

Hence pre-sleep protein consumption does not make you gain fat. Now you know.

References

Allman BR, Morrisey MC, Kim Js et al (2020). Lipolysis And Fat Oxidation Are Not Altered With Presleep Compared With Daytime Casein Protein In Resistance-trained Women. J Nutr. 150(1): 47-54. DOI: 10.1093/jn/nxz186.

Kinsey AW and Ormsbee M (2015). The Health Impact Of Nighttime Eating: Ols And New Perspectives.Nutrients. 7(4): 2648-2662. DOI: 10.3390/nu7042648

Saracino PG, Saylor HE, Hanna BR et al (2020). Effects oF Pre-sleep Whey Vs Plant-based Protein Consumption On Muscle Recovery Following Damaging Morning Exercise. Nutrients. 12(7): 2049. DOI: 10.3390/nu12072049.

Snijders T, Trommelen J, Kouw IWK et al (2019). The Impact Of Pre-sleep Protein Ingestion On The Skeletal Muscle Adaptive Response To Exercise In Humans: An Update. Front Nutr. 6(16). DOI: 10.3389/fnut.2019.00017.

Understanding The Recovery Of The Intervertebral Disc

Picture from Wikipedia

I came across a recent paper (Feki et al, 2024) about the positions which help our intervertebral discs recover and heal when we sleep. I have written at least 5 articles on intervertebral discs. This is definitely still a topic that I get questions from most often among my friends and patients alike. Almost every single one of my friends and patients are fearful of having a 'slipped intervertebral disc' whenever they have low back pain (LBP). The intervertebral discs (IVD) have a really bad reputation for causing significant pain and disability in many people.

Here's a quick review if you did not read those 5 articles.

The IVD consists of a very tough outer layer called the annulus fibrosis (AF). It is made of of several layers of fibrocartilage consisting of Type I and II collagen fibers. The AF protects the soft, gel-like substance in the middle known as the nucleus pulposus (NP). The NP helps distribute pressure evenly across the IVD and prevent excessive forces on the spine.

See how thick the AF is from the picture above? Here's something else you need to know. There is a cartilaginous endplate between the AF and the vertebra (the spine). The endplates hold the IVD in place. It allows load to be spread evenly and to provide attachment to the IVD. This creates a super strong connection to the AF making it impossible for the IVD to 'slip' out of position.

Yes, our discs are actually very strong and hardy. How strong are our IVD's? In a published study on thoracic discs in the young (28 years old plus minus 8 years) , it took about 740 pounds of force to compress the disc height 1 mm. For the older subjects (70 years young plus minus 7 years), it took almost 460 pounds of force. Note that these are on cadavers with the muscles and bones cut away (Stemper et al, 2010).

The IVD's withstand a whole variety of complex forces in our daily activities and also when we exercise. This can lead to significant structural changes in terms of volume, area and height of the intervertebral disc. It can lead to an increase in disc stiffness and a decrease in interdiscal pressure.

In order for your discs to remain healthy and strong, it is dependent on a recovery phase which serves to prevent premature disc degeneration. This happens during a period of nocturnal rest i.e. when you sleep at night.

This phenomenon of disc recovery has been documented extensively through many studies using MRI and intradiscal pressure measurement. Fluid dynamics (water content) within the disc are considered a primary factor in recovery, while it's intricate multiscale structure and viscoelastic (behaving with both liquid-like and solid-like) properties also play key roles.

Feki et al (2024) in their review collated, analyzed and evaluated the existing in vivo (human) and in vitro (in controlled environments) on this topic to provide a comprehensive understanding of this recovery process to enable future advancements in medical treatment and biomedical enginerring solutions to enhance the natural recovery processes of intervertebral discs.

As it is a very long (and complex) review article (Feki et al, 2024), I am simply highlighting the optimal recovery positions (pictured below) for intervertebral disc rehydration. 

Picture from Feki et al, 2024

(a) prone (b) modified press up/ push up position (c) supine with under knee and back support

(d) and (e) side lying with lumbar flexion with pillows between legs

(f) and (g) side lying with and without manual distraction

(h) 50 degrees gravity assisted position (i) 110 degrees supported sitting

(j) inclined sitting with lumbar support

So, you see from the pictures that some of the supposedly 'poor' posture/ positions you were told, are actually good for your intervertebral discs.

References

Feki F, Zairi F, Tamoud A et al (2024). Understanding The Recovery Of The Intervertebral Disc: A Comprehensive Review Of In Vivo And In Vitro Studies. J Bionic Eng. DOI: 10.1007/s42235-024-00542-2

Fournier DE, Kiser PK, Shoemaker JK et al (2020). Vascularization Of The Human Intervertebral Disc: A Scoping Review. JOR Spine. 15: 3(4): e1123. DOI: 10.1002/jsp2.1123.

Stemper BD, Board D et al (2010). Biomechanical Properties Of Human Thoracic Spine Disc Segments. J Craniovert Junct Sp. 1(1): 18-22. DOI: 10.4103/09774-8237.65477

A Better Way To Train Your Quads

Leg extension exercise

Those of you who go to the gym would have been told to sit up straight when doing the leg extension exercise. Well, perhaps that may not be the best way to do the leg extension exercise. Especially if you want to get bigger and stronger quadriceps femoris muscles (below).

Right quadriceps femoris muscle

A recent study (pictured below) was initiated by Larsen et al (2024) to compare the effects of sitting upright (90 degrees hip flexion) versus recumbent sitting (40 degrees hip flexion).

The participants' right and left lower limbs were randomly assigned to the hip flexion 40 degrees or 90 degrees for the leg extension exercise. Note that 0 degree is no flexion (or bending) in the hip joint, like in standing.The participants in the study had a familiarization session at week 1 so they knew what to do.

The subjects then completed a 10 week training program comprising of 2 strength training sessions each week. This consisted of 3 sets of exercises from week 1-5 and from week 6-10 onwards, 4 sets of exercises. They performed either 15-20 reps of leg extension or if they cannot reach 15-20 reps to failure (where the quads cannot do another rep).

2 pre and post training measurements on the proximal and distal rectus femoris and vastus lateralis muscles were done with ultrasound imaging to compare results.

The findings were that the quadriceps femoris muscle hypertrophied following the 10 weeks of strength training. The rectus femoris part of the quadriceps femoris had significantly greater hypertrophy in both the proximal and distal regions at 40 degrees of hip flexion compared to 90 degrees hip flexion. 

There were however no hypertrophy changes in the distal proximal and distal regions of the vastus lateralis muscle. This finding was expected as the vastus lateralis is a single joint muscle and its muscle length was constant and did not change during both hip positions.

The authors concluded that performing the leg extension exercise with 40 degrees of hip flexion had superior increases in hypertrophy of the rectus femoris muscle compared to 90 degrees hip flexion. So definitely not always true that you need good posture/ exercise form when exercising.

This is attributed to the longer muscle length in the rectus femoris when the leg extension exercise is performed with the hip at 40 degrees flexion. Note that the rectus femoris is a 2 joint muscle where it can both flex the hip and extend the knee. The other 3 muscles in the quadriceps femoris are capable of only extending the knee. This makes the rectus femoris most prone to muscle strain injuries especially when sprinting and kicking.

The authors suggest that training the rectus femoris with 40 degrees hip flexion would make it stronger and offer a protective effect against rectus femoris strain injuries.

Reference

Larsen S, Kristiansen BS, Swinton PA et al (2024). The Effects Of Hip Flexion Angle On Quadriceps Femoris Muscle Hypertrophy In The Leg Extension Exercise. Sport Rxiv. DOI: 10.51224/SRXiv.407

What Does The Fibularis Longus Muscle Have to Do With Knee Pain?

R Peroneal Longus (Peroneal Longus)

After 3 previous knee surgeries, and also seeing many patients (with knee pain) over the last 25 years I've learnt a lot about treating knee pain. So I was pleasantly surprised to learn more and hopefully get even better at treating knee pain.

Many of our patients come to our clinic with patellofemoral joint pain (PFP) or pain in the front/ side of the knee especially during loading activities like running, walking, squatting, jumping and going up and down stairs. Studies have shown that 23 percent of all adults will get PFP, and 50 percent of them will experience PFP that lasts up to 20 years!

I've written previously that the hip often affects the knee too. Well, a group of researchers found differences in fibularis longus (or peroneal longus) muscle size and even activation between individuals with PFP and healthy controls. This was done using ultrasound imaging in weight bearing (Jaffri et al, 2024).

Of the 60 subjects (30 healthy, 30 with PFP) investigated, there was a statistically significant result for the healthy group in the size (larger) and activation for the fibularis longus (or peroneal longus) muscle.  The group with knee pain had smaller fibularis muscle and it did not work (or switch on) as quickly as those without knee pain.

Note that besides its role as a evertor of the foot, the fibularis longus works together with abductor hallucis longus to stabilize the medial longitudinal arch after heel strike. Hence slower activation and smaller (weaker) of the peroneal longus muscle in a weight bearing position may contribute to arch flattening in PFP subjects. This add to faulty mechanics at the foot and ankle joints. 

This further explains the fact that the smaller (and weaker) the fibularis longus is, the higher likelihood of the foot pronating. This leads to knee valgus (knee facing inwards), which is a major biomechanical abnormality in individuals with PFP.

I am certain not every health professional reading this will agree since clinical treatment guidelines to treat PFP are still being developed as there is a lack of agreement about what actually causes PFP. Not everyone agrees that hip adduction, increased knee internal rotation, foot pronation etc causes PFP.

If you have persistent knee pain that does not seem to go away, please show the health professional treating you this article. Other than the hip, your fibularis longus muscle may help with your knee pain. And I am not talking about just strengthening it.

Better still, come see us at our clinics.

Reference

Jaffri A, Schwarting A and Beallow A (2024). Impairments In Peroneal Muscle Size And Activation In Individuals With Patellofemoral Pain In Weight-bearing Position. J Foot Ankle Res. 17: e12014. DOI: 10.1002/jfa2.12014

Fiblaris logus is part of the lateral line

10 Bodyweight Squats Or Walk 30 minutes?

Last week I wrote about how a fast or slow metabolism does not influence your weight gain or weight loss. For those of us who run or exercise to manage our weight, it definitely does burn calories while you are exercising, but it does not boost your metabolism, at least not in the long term. 

Well, I can suggest a fairly simple way to improve your blood sugar regulation better than a single 30 minute walk if you're pressed for time. Also helps to lower cancer and cardiovascular related mortality.

A recently published study (Gao et al, 2024) on overweight and obese subjects who either sat uninterrupted for 8.5 hours or had interruptions while sitting with matched energy expenditure and duration. A 30 minute walk at 4 km/hr, sitting with 3 minutes walking at 4km/hr or squatting 10 times every 45 minutes.

The authors found that doing 10 body weight squats every 45 minutes or short frequent walking breaks during a 8.5-hour period of sitting improved blod sugar regulation better than a single 30 minute walk (at 4 km per hour).

These superior benefits seemed to be associated with increased muscle activity intensity in their targeted muscle groups during frequent transitions from sitting to activity.

These brief, intense bursts of activity (bodyweight squats in the study) termed 'exercise snacks' offer a simple yet strong strategy to mitigate the health risks associated with our sedentary lifestyles. It is not too difficult to get up from sitting and do 10 bodyweight squats every 45 minutes (or when you can). You can also do burpees or run up stairs to break up sedentary periods. Those at home may want to do some dumb bells/ kettle bells swings.

Of course some other people may prefer to walk outside for fresh air, sunlight meeting other people and psychological/ mental health benefits. Or a combination of exercises and walks. Works well too. Go on and add some some exercise snacks into your day.

References

Gao Y, Li QY, Finni T ey al (2024). Enhanced Muscle Activity During Interrupted Sitting Improves Glycemic Control In Overweight And Obese Men. Scan J Med Sci Sp. 34(4): e14628. DOI: 10.1111/sms.14628

Stamatakis E, Ahmadi MN, Gill JMR et al (2022). Association Of Wearable Device-measured Vigorous Intermittent Lifestyle Physical Activity With Mortality. Nat Med.28: 2521-2529. DOI: 10.1038/s41591-022-02100-x

Will My Metabolic Rate Slow Down As I Age?

Picture from Genesispersonalfitness

Looks like we have been very wrong about our metabolic rates. Whether our metabolic rate is fast or slow, it cannot predict weight gain. 

Metabolisms varies by 20 percent or more from person to person regardless of activity level or body composition (Rimbach et al, 2022). So for those of us who run or exercise to manage our weight, yes it does burn calories, but it does not boost our metabolism, at least not in the long term. 

The researchers also found that if you happen to be on the skinnier side, it is not that you have a faster metabolism (Rimbach et al, 2022).

The researchers measured metabolism using doubly labeled water. Participants in their studies drank water containing hydrogen and oxygen isotopes, which researchers can track in the body. How quickly they lost the isotopes through peeing, sweating and even breathing were monitored. These enabled them to ascertain how many calories are burned in that time, or what is known as total energy expenditure i.e. metabolism.

The total energy expenditures studied were measured at 2 time points, ranging from 2 weeks to more than 8 years. Body size and composition were adjusted for since more cells burned more calories and fat and muscle burned calories at different rates. 

The researchers found that the subjects' daily energy expenditures did not change over time. A person with high metabolism today will have it high in a few months or even a few years. Likewise, a person with slow metabolism today will still have it slow in a few months or a few years.

Here's the good news. The researchers found that having a slow metabolism did not make people more likely to gain weight. Nor did having a fast metabolism less likely to gain weight.This is attributed to the human brain's outstanding ability to match calories consumed to calories burned in the long run.

So, running or any exercise is not a magic metabolism booster. Exercise is complex and it affects how our body regulates all its cells, which in turn affects hunger, fullness, immune function and even behaviour. 

Those who exercise will obviously see day to day fluctations in the calories burned. More on long runs/ hard days compared to recovery days. Our bodies adjust how much energy we use during our non exercise hours to keep the total caloric burn within a fairly narrow range.

So, you do not gain weight as you age because your metabolism slows down (Pontzer et al, 2021). We have all been mislead by this myth. We should not use it as as excuse. You gained weight because we do not move and/ or exercise as much and because we may have lost some muscle mass.

Reference

Pontzer H, Yamada Y, Sagayama H et al (2021). IAEA DLW Database Consortium. Daily Expenditure Through The Human Life Course. Science. 373(6556): 808-812. DOI: 10.1126/ science.abe5017

Rimbach R, Yamada Y, Sagayama H et al (2022). Total Energy Expenditure Is Repeatable But Not Associated With Short-term Changes In Body Composition. Nat Commun 13,9. DOI: 10.1038/s41467-021-27246-z

Cold Play?

ST 100524

I just wrote about how cold (ice) immersions were not effective last week! And Straits Times does a full page article on the front of their Life Section today (100524).

"I noticed a significant improvement in my alertness and reduced muscle soreness after including cold therapy ....." said a business owner selling ice baths.

No, evidence says cold immersions does not help with recovery. Actually cold immersions inhibits recovery. Researchers (Roberts et al, 2015) have found that cold water immersion after hard exercise suppressed signaling pathways associated with recovery. This suppression lasted for several days.

The newspaper article also credited Wim Hof (the Dutch iceman) for popularising cryo or ice therapy - just like my post. Purveyors of commercial health and wellness have definitely jumped on the same bandwagon. I cannot comment on the various beauty and skincare benefits (such as reduction in cellulite and what not) as touted by the wellness professionals quoted. Please do your due diligence.

Reference

Roberts LA, Raastad T, Markworth et al (2015). Post-exercise Cold Water Immersion Attenuates Acute Anabolic Signaling And Long-term Adaptations In Muscle To Strength Training. J Physiol 593(18) : 4285-4301. DOI: 10.1113/JP270570.

Can Cycling Lower Your Risk Of Knee Arthritis?

Picture by Dennis Thong

I have written previously on what causes osteoarthritis (OA). Definitely not because of overuse nor a mechanical wear and tear process. Especially for those without any previous history of knee truma/ injury, there is very good evidence that OA is actually due to metabolic factors. Well, now a new study (Lo et al, 2024) suggests that cyclists are less likely to develop OA in their knees.

Lo et al (2024) studied 2600 older adults with and without knee OA using knee X-rays, subjective knee pain, and a questionnaire regarding their lifetime history of various physical activities during 4 periods of their lifes: 12 to 18 years old, 19 to 34, 35 to 49 and over 50. 

The study used 3 different outcomes. Persistent knee pain, OA based on X-rays (radiographic OA) and symptomatic OA (having both knee pain and radiographic OA. Note that what is seen on X-ray (OA knees) does not always correspond to pain. This means that some subjects had knee radiographic OA but NO pain.

Almost half the subjects reported some history of cycling and these subjects were less likely to have OA in their knees. How much less? Those with any history of cycling were 17 percent less likely to have knee pain, 9 percent less likely to have radiographic OA and 21 percent less likely to have both. 

Half of those who cycled reported only cycling regularly during one of the 4 age periods, usually the youngest age period from 12 to 18 years old.

Those who cycled during 1,2,3 or 4 of the periods studied reduced their risk of symptomatic OA (i.e. painful knees) by 17, 19, 28 and 43 percent. Meaning lifelong cyclists reduced their risk of symptomatic OA by nearly 50 percent.

The researchers also found that subjects with a history of swimming, strength training and running had lower rates of OA. This is consistent with previous evidence that running DOES NOT ruin your knees despite what every non runner and ex runner you know will insist running does.

You may love watching the beautiful game, but a history of playing the beautiful game (football) even just as a teenager bumped up knee OA risk by a factor of 2. This elevated risk remained even after adjusting for BMI, suggesting that the problem is likely related to acute knee injuries suffered while playing football. 

Picture by Dennis Thong

The researchers concluded that more cycling is associated with less knee pain and favorable to knee health and should be encouraged. 

If you have never cycled previously and would like to start, do note that almost half or the current or former cyclists in the study had radiographic evidence of OA. A quarter of them had symptomatic OA (painful knees). Is cycling better for OA once you do develop OA compared to say running? Is cycling capable of slowing its progression? Currently, we still do not know.

Those of you who have been always been cycling, you definitely have another reason to do so. 

Reference

Lo GH, Richard MJ, Kriska AM et al (2024). Bicyling Over A Lifetime Is Associated With Less Symptomatic Knee Osteoarthritis : Data From The Osteoarthritis Initiative. Med Sci Sp Ex. DOI: 10.1249/ MSS 0.0000000000003449

All pictures by Dennis Thong. Many thanks to Dennis and Eugene Phua for the pictures.

Are Cold (Ice) Water Immersions Effective?

Picture from Scienceforsport

I used to have lots of ice packs in the freezer when I was still competing. The commercial ones plus bags of peas and mixed vegetables (pictured below). Used to put it on my shin or anywhere that hurts. However, I did not do the ice/cold water immersions. It was way too cold for me (since I had less body fat then) and I did not feel it helped. 

Good for icing

However, the more we know about cold water immersion (from research), the more it seems we (athletes and non athletes) have it wrong. Regular immersion in cold water significantly inhibits recovery from strenuous exercise. 

When our muscles feel sore after strenuous exercise, it is a consequence of doing physical activity to which we are unaccustomed or not used to. That can be a hard run, gym session, a few hours of golf or a repetitive household chore that took longer than you expected.

Here's an example of how our muscles get overloaded. If you continuously stretch a rubber band, the rubber band becomes frayed. Likewise your muscles sustain micro tears when you exert too hard. The damage causes a few hours to days of inflammation, swelling and soreness. When it's severe, you get delayed onset of muscle soreness or DOMs.

This is normal and also an essential part of muscular adaptation to exercise, also known as the overload principle. If the stress (exercise) is applied regularly, and you get enough recovery, the muscles adapt, get stronger and bigger by laying down new fibers. Just like a construction crew assembling steel beams to support the infrastructure of a building.

Ice immersion inhibits this process. Researchers (Roberts et al, 2015) have found that cold water immersion after hard exercise suppressed signaling pathways associated with recovery. This suppression lasted several days. Another group of researchers (Fuchs et al, 2020) showed that ice bathing reduced the body's muscles uptake of dietary proteins, which is important for growth and cell maintenance.

The conclusions of 2 recent meta-analyses support the suppressed signaling pathways and reduced dietary protein intake mentioned above. Grgic (2022) showed that cold water immersion reduced exercise related strength gains while (Pinero et al, 2024) showed that ice bathing immediately after weight training inhibited muscle growth.

So, whether you are strength training to improve athletic performance or just about anyone who needs to repair and rebuild your muscles after exercise, you need to reconsider if you should use cold water immersion after your exercise/ training.

Why are athletes and non athletes still doing cold water immersions? Social media is probably the cause. Wim Hof (the Dutch iceman) says that cold "activates" your metabolism and strengthens the body's immune response. Others on Tik Tok swears that ice baths improves alertness and concentration. Purveyors of commercial health and wellness have likely jumped on the same bandwagon.

Perhaps sports scientists and researchers have to share some of the 'blame'. These articles are written and published in scientific language, using unrelatable sequence and you have to pay to access them.

Possibly, only the articles with the most sensational findings/ conclusions make it out of academia. Since it is not communicated well with the public, there is a gulf between the lab and the average lay person. This gulf is then filled gleefully by fitness influencers and wellness 'gurus' who share their knowledge on unregulated social media platforms.

I ice my sore body parts still, because it does reduce muscle pain. I fell and bruised my elbow last week and the icing provided pain relief as the ice numbs the skin and blocks pain signals to the brain. 

Pain is subjective. To you it may be a 3/10 pain, to me, it may be 7/10 or vice versa. Pain cannot be studied objectively. Pain perception is definitely different to cellular recovery and to actually speed up recovery, you need to sleep well.

References

Fuschs CJ, Kouw IWK, Churchward-Venne TA et al (2020). Postexercise Cooling Impairs Muscle Protein Synthesis Rates In Recreational Athletes. J Physio. 598: 755-772. DOI: 1113/JP278996.

Grgic J. (2023). Effects Of post-exercise Cold-water Immersion On Resistance Training-Induced Gains In Muscular Strength: A Meta-analysis. Eur J Sp Sci. 23(3): 372-308. DOI: 10.1080/17461391.2022.2033851.

Roberts LA, Raastad T, Markworth et al (2015). Post-exercise Cold Water Immersion Attenuates Acute Anabolic Signaling And Long-term Adaptations In Muscle To Strength Training. J Physiol 593(18) : 4285-4301. DOI: 10.1113/JP270570.

Pinero A, Burke R, Augustin F et al (2024). Throwing Cold Water On Muscle Growth: A Systematic Review With Meta-analysis Of The Effects Of Postexercise Cold Water Immersion On Resistance Training-induced Hypertrophy. Eur J Sp Sci. 24: 177-189. DOI: 10.1002/ejsc.12074

Shouder Keeps Clicking But No Pain

I had a patient come in to our clinic this week complaining that his shoulder keeps clicking and popping with occasional discomfort (but not pain).

I shared with him an article published earlier this month where 100 patients with suspected rotator cuff tendinopathy and/ or tearing underwent MRI investigation. 

Indication for MRI was when the patients had weakness on testing of the rotator cuff muscle(s) or symptoms resistant to conservative treatment . This is inclusive of at least a 6-week course of physiotherapy. The presence of subjective mechanical symptoms, including clicking or popping was recorded prior to MRI.What the researchers were looking for was the presence of full or partial thickness rotator cuff tearing and biceps long head subluxation.

Results showed that 60 percent of the patients reported subjective mechanical symptoms in their affected shoulder. However only 42 percent of patients had full thickness rotator cuff tearing, 69 percent had partial tears while only 14 percent had biceps long head subluxation.

The authors concluded that subjective mechanical symptoms were not associated with any rotator cuff tearing, biceps long head subluxation. 

However, older age was associated with partial and full thickness rotator cuff tearing. Subjective shoulder mechanical symptoms has the ability of only 44 percent in predicting partial and full thickness rotator cuff tears. Patients may be reassured that clicking or popping sensations alone does not necessarily mean structural shoulder damage.

This article highlights the difficulty of diagnosing shoulder pain/ disorders based solely on symptoms like clicking and/ or popping. I have previously written and explained about this before. The clicking and popping sounds do not really matter, especially when there is no pain. Plus abnormal MRI findings happen in patients with no pain as well.

Reference

Zhang D, Dyer GSM and Carp BE (2024). The Significance Of Subjective Mechanical Symptoms In Rotator Cuff Pathology. J Shd Elbow Surg. 3: S1058-2746(24)000227-1