Sunday, August 14, 2022

Are We Losing Talented Young Athletes?

Picture by Richard Seow from Flickr
I came across a really interesting article (Abbott et al, 2020) this week measuring adolescent maturation with respect to sports. 

Our Singapore national school sports competitions use chronological age to categorize adolescent athletes. Australia does the same when it comes to their age group swimming competitions.

The researchers in the paper use a handful of physiological measurements to come up with an estimate of an adolescent's relative age. So, for two 13 year olds born exactly on the same day, one of them can be an early maturer with a relative age of say 13 years and 7 months. The other adolescent can be a late maturer with a relative age of 12 years and one month. They both have the same birthdate, however, in practice one has a 18 months maturity advantage over the other.

The table in the picture above shows the researchers' maturation measure applied to age group swimmers in Australia competing in the 100 m freestyle. You can see that all the swimmers at the top end of this Australian age group are those in the "early" or "early-normal" categories. They are the faster swimmers.

Look at the "late" maturers column, it's a whole long line of zeros. If you look at it from another perspective, it also means that Australia is losing 50 percent of their talent pool. These swimmers probably started swimming with the rest of their age cohort, but by age 13, they probably all became disillusioned and dropped out. So where did all these slowly maturing kids go? Did they all decide to play computer games instead? Hopefully, they found another sport to participate in.

To find their next generation of elite swimmers, Australia is using a high stakes, winner takes all competitive swim competitions. The effect of those competitions was to chase away half the cohort of young swimmers away from swimming.

Now, if we relate this to Singapore's own school sports scene, does this mean that the Singapore Sports School and other schools' Direct School Admission (DSA) selection criteria is also slightly flawed? Perhaps that can explain why many of these 'talented' kids who are early maturers (at 13 years old when they go to Secondary school) don't carry on competing and drop out. 

If you read my earlier post, it it reasonable to say that some of these early maturing athletes in the Sports School or DSA programs would have exceled in any physical screening tests. Just like my classmate in that post who reached puberty and had his growth spurt earlier than us in Primary school. He was physically superior to everyone else. That's how he won all his track events earlier. When the rest of us "caught up" when we hit puberty, he didn't have that advantage anymore.

Having been raised on victories from young, they may not comprehend or accept defeat. Early victories may have paved the way for defeat and giving up eventually.

Please take note that I am not criticising the Singapore Sports School or the DSA programs currently in place. I am just suggesting that our local childhood talent selection programs, on closer examination, are not as meritocratic as they may seem.

A child/ adolescent who is a late maturer may not necessarily be not talented in sports. It may be a lack of motivation. No child or adolescent will persist or strive in an athletic activity if they do not feel they are competitive with their peers.

My wishes for these national schools competitions are that that they can provide opportunities for students to experience joy (and of course heart break) from exercise and competition. To lay down life-long habits of physical activity. And finally to provide those with ability for futher higher level competiton to represent their country. 


Reference

Abbott S, Hogan C, Castiglioni MT et al (2020). Maturity- related Developmental Inequalities In Age-group Swimming: The Testing of 'Mat-CAPs' For Their Removal. J Sci Med Sp. 24(4): 397-404. DOI: 10.1016/jsams.2020.10.003

Sunday, August 7, 2022

Are Sports Drinks Overhyped?

My patient was asking me what I fuel myself with for my weekly Saturday bike rides. He knows I usually ride between 70-90 km. He was shocked when I said that I only bring a banana and a bottle of water with a slice of lemon for taste. 

Perhaps he had been influenced by social media and advertisements, and felt that hydrogels, superstarch, theanine, isotonics and even coconut water packed with potassium were better for absorbing carbohydrates into our system while exercising.

SuperStarch?
Perhaps some of the latest choices mentioned earlier may give an extremely small edge. Do they perk you up in the morning, help you metabolize energy, increase your focus and 'protect' your body as they claim? Especially since none of them are solidly backed by research. Will you go and order the latest offerings? 

I've written before that sports drinks definitely cannot replace your sodium levels during exercise. What it can definitely do is to provide you with some carbohydrates for fuel during prolonged (longer than 90 minutes) exercise to sustain your level of performance.

Results suggest that sports drinks can fuel you to maintain athletic performance. In the article referenced below, the authors wanted to know if a pre-exercise meal affects sports drink effectiveness. The subjects (cyclists) rode 105 minutes at lactate threshold followed by a 10 km time trial under 4 conditions. No breakfast before the ride with a placebo sports drink. No breakfast with a real sports drinkBreakfast with a placebo sports drink and breakfast with a real sports drink.

The breakfast the riders had were consumed 3 hours before the exercise. It had 824 calories, consisting of two thirds conbohydrates. The real sports drink had 8 percent maltodextrin (works like glucose but has no taste) while the placebo was just artificially sweetened. The sports drink was consumed every 15 minutes during the first 105 minutes ride and halfway mark of the 10 km time trial. 

Those who had the real sports drink with breakfast managed 198 watts in the time trial, those without 197 watts, not much difference. Strangely enough the results did not give any boost to the cyclists who fasted (no breakfast). I would have thought that the sports drink would help those who did not eat breakfast, ride better. Other studies did find a difference. Using the real sports drink helped with or without breakfast

There was definitely a negative effect for those who skipped breakfast without the real sports drink. With breakfast but no sports drink the cyclists managed 173 watts, with no breakfast, no sports drink it was 154 watts. They also had the highest rate of perceived exertion.

Note that at the start of the time trial, those who had breakfast with placebo drinks kept up with those with breakfast and real sports drink. As the time trial progressed and fuel stores were used up, those without the real sports drink fell farther and farther behind since their placebo drink failed to fuel them. 

This study shows that consuming carbohydrates during prolonged exercise definitely makes a difference. What I liked about the study was that the subjects did not know if their sports drink was real or placebo. The time trial started only after 105 mins, long enough for carbohydrate stores to be depleated. There wes also no funding (from the sports drinks industry) for this study, so less chance of any bias.

If you are out racing or training for a few hours or more, commercial sports drinks aren't the only option. Neither is hydrogel, superstarch or any of the latest offers. Many sports drink companies may advertise their specialized formulations, but the 3 basic ingredients needed are watersugar and salt. Beyond these 3 ingredients the science gets a lot weaker. 

Many triathletes drink flat Coke (see picture below) in the Ironman events and eat bananas or dried figs. I'll usually just have a banana, dried raisins or dates. Just make sure you have something to suit your palate. Oh! And remember not to skip breakfast.

Reference

Leari SK, Ghiarone T, Silva-Cavalcante MD et al (2019). Cycling Time Trial Performance Is Improved By Carbohydrate Ingestion During Exercise Regardless Of A Fed Or Fasted State. Scan J Med Sci Sp. 29(5): 651-662 DOI: 10.1111/sms.13393.

You can the dark Coke stains on the front Mark Allen's top after beating Dave Scott after 6 attempts and finally winning at the 1989 Hawaii Ironman. 

*Picture taken from my book Ironwar by Mark Fitzgerald, Velopress 201.

Sunday, July 31, 2022

Searching For Wellness?

A patient who came to our clinic yesterday mentioned that one of his staff had just left his team to start a wellness business.

Wellness seems to be a 'hot' industry at the moment. Wellness centers offering to improve your personal 'wellness' have sprouted up all over Singapore. Flotation therapy rooms, cryotherapy, ketamine clinics, juice cleansing bars, electromagnetic therapy centres etc, you can find them all in Singapore.

There is a space near where I live that offers everything from aromatherapy, massages, healing salts and art therapy, that advertises itself as a calm oasis for mind, body and soul. It has been two tough years with Covid-19 and perhaps more people need wellness centers to ease their stress and improve their mental health and physical well being. 

The wellness industry is getting bigger by the minute. A McKinsey survey last year estimates the wellness market to be in excess of 1.5 trillion with annual growth of 5-10 percent.

The wellness industry may offer people hope, especially when we do know that modern pharmaceuticals/ medicine cannot cure all ills. When a patient does not respond to conventional treatment, they will seek unorthodox treatment to see if it works. However the wellness movement may cause a general distrust of scientific authority. This could be an issue in pandemic times, when thousands have died through misinformation.

Singaporeans may remember the 65 year old grandmother who was hospitalised after taking Ivermectin at the urging of her religious friends to protect herself from Covid-19. 

There are skeptics who say that much of this wellness stuff does not work. Will lavender oil cure your depression? Will drinking lettuce juice help you sleep better? How about activated charcoal detoxifying your body? Vitamin supplements

I do not have anything against wellness centers. I am also not against using pharmaceuticals when needed, although they sometimes have harmful side effects. Pharmaceuticals are often aggressively marketed to doctors which then gets passed on to patients. As a result we are often overprescribed.

My son was recently prescribed a 'special' pair of spectacles costing over $500 on top of a $700 + consultation fee and asked to come in for multiple sessions of therapy to help with his vision. A second opinion with a pediatric opthalmologist confirmed that his eyes are normal. I immediately asked for a full refund for the glasses (which was independently checked to be a simple pair of reading glassess). My son has 6/6 vision and definitely does not need reading glasses.

I gues what I'm trying to get across here is my humble opinion to be aware as you explore wellness options. Don't be pressured to buy expensive packages at your first few sessions. See and feel for yourself if it works for you. Take your time to decide. Be wary of individuals or centres that prey on your fear in order to get you to commit. Seek second opinions.

Sunday, July 24, 2022

Is High Mileage Necessary To Run Fast At Your Races?

Maroochydore, Queensland- great for long runs
My colleagues and I were discussing just how much mileage a runner can safely increase before running the risk of injury. It does seem like mileage is a tricky topic for many runners. Often many runners would ask other runners how far they are running each week. 

Most runners track it. Some believe it holds all the keys to being successful in running (more is good, less is bad).  

My first running coach in secondary school taught my teammates and I that consistency in running and intervals were necessary for fast race times (we did cross country - 4.8 km and track and field - 3000m longest event). My junior college running coach emphasized quality over quantity (no junk miles). So why do some coaches and elite runners swear by high mileage?

Running an easy kilometer is totally differerent from doing 5 x 200 m at 30 secs a rep (that's a 2:30 min  kilometer pace). Recovering from the 5 x 200 m will be different compared to running an easy kilometer at say 6:00 min per kilometer.

Perhaps we should consider training what muscle fibers we have in our bodies before deciding on mileage. We all have 3 main types of muscle fibers. Type I or slow twitch muscle fibers which are the smallest and produce the least amount of forces, but once trained can go all day long without fatiguing. They also help to hold and stabilize our posture. They are fueled by aerobic energy. 

Picture by Kurt Rawlins from Pinterest
Type II or fast twitch muscle fibers which are further divided into Type IIa and Type IIx (also known as IIb). These are larger muscle fibers and produce a greater and quicker force (than type I), but have less mitochondria, myoglobin and capillaries (compared to Type I) and are prone to fatigue quicker.

Type IIa (also known as intermediate muscle fibers) is a mixture of Type I and IIx fibers. They use both aerobic and anaerobic energy systems and fatigue slower than Type IIx. Proper training of Type IIa fibers will increase their ability to utilize aerobic energy, translating to greater endurance.

Type IIx are the largest muscle fibers and produces the most forces but are inefficient and fatigues quickly as it has low oxidative capacity and relies on anaerobic energy.

If you only do easy long slow runs, you utilize your slow twitch (Type I) fibers. If you run harder, your intermediate Type IIa fibers kick in to help. If you are required to do a hard 400m sprint or longer then all 3 types of fibers are used.

All the muscle fibers are fueled by 3 energy systems, one aerobic and 2 anaerobic. The Phosphagen energy system (or ATP-CP system) uses creatine phosphate to provide energy that can only last 10-15 seconds at high speed. This is what is used when you are sprinting all out.

The next anaerobic (glycolytic) system uses carbohydrates to provide another short source but fast acting energy. Medium to high intensity runs utilize this system. 

Lastly, the aerobic energy system which takes 30-40 seconds to start (since it takes time to deliver increased oxygen to your muscle fibers) and uses carbohydrates and fats to deliver long term, high volume energy for your muscles.

So, if you're training for a good timing in a 10 km race, that is at least 90 percent fueled by the aerobic system. However a fast 10 km will require help from your intermediate and fast twitch fibers. It will NOT be enough to do just low intensity, long, slow runs which targets your slow twitch fibers. You need to train your intermediate fibers as well with tempo runs (race pace you can hold), 1km intervals with short recovery, hill reps of 300-600 metres etc.

Runnning definitely damages the muscle fibers used in training and racing. The faster you run, the more fibers damaged. Your slow twitch muscle fibers starts to run out of fuel and fatigue after 60-90 minutes and you will be using intermediate fibers to compensate. That's why you recover easily when you do easy slow runs while faster and longer efforts require you to rest 2-3 days before your next demanding session.

Your bone and tendons require more time to adapt compared to muscles so do not ramp up volume and speed too quickly otherwise you could sustain a stress fracture.

As for your energy systems, your Phosphagen systems recuperates in about 3 minutes. Your aerobic system needs about a day to replenish its muscle glycogen stores. The glycolytic system requires at least 2-3 days to recover from a tough anaerobic workout.

If you are training for a marathon, you obviously have to run higher mileage compared to training for a 3000m track race or a 5 km run. 

Understand the demands of your race. Plan and schedule workouts to meet those demands. Then you can add up your mileage. So mileage is not a training plan. It's simply counting the total distance you ran for the week.

Moreover our fitness, age, physical make up and experience makes us unique or n = 1. Just because someone else in your running club is running 100 km a week does not mean you should. 

Ultimately, the mileage you're able to chalk up is limited by the recovery needed between your workouts, not so much by how far or fast you want to run.

Wouldn't it be better to identify the workouts that target the muscle fibers and energy systems required to meet your race goals than to focus on your mileage?


References

Baker JR, McCormick MC and Robergs RA (2010). Interaction Among Skeletal Muscle Metabolic Energy Systems During Intense Exercise. J Nutri Metab. DOI: 10.1155/2020/905612.

McArdleWD, Katch FI and Katch VL (2000). Essentials Of Exercise Physiology. 2nd Edition. Baltimore: LippincottWilliams and Williams.

Sunday, July 17, 2022

Keep Jogging Or Rest?

Picture by Richard Seow
For those of you old enough to remember former Singapore runner, Syed Ahmad Taha - he's the last Singaporean runner to run the 10,00m on the track in under 33 mins before Soh Rui Yong in 2012, and Melvin Wong in 2015 at the Singapore SEA Games. Syed ran the 10,000m in 32:41 min in 1990.

I remember watching him do interval training (the original HIIT) at the old National Stadium back in 1988. When I was a teenage runner, those intervals we did certainly did not have such a fancy name like HIIT. You run 15 intervals or repetitions of 400m with a one minute rest in between or the coach will say run 6 x 1km going every 5 minutes (meaning if you run your kilometer in 3:50 min, you get 1:10 min rest before starting again).

Syed Ahmad Taha was doing 25 x 400m with a 60 seconds rest and he would be lying on the track recovering while you could see his heart thumping away. He would spring back up as his coach told him to get ready for the next rep. No super shoes, no super spikes back then in 1990. Respect!

A quick question for all runners before reading the rest of this article. During your track intervals training, do you normally continue to jog/ run after the interval or just rest before starting the next rep?

Well, no prizes for guessing that this post compares active recovery (jog/ run) versus passive recovery (lying down or slow walk) between repeats during interval training.

The study had well trained runners do 4x 2:00 minute at their maximum aerobic speed at an outdoor track, with a 2 minute rest or 2 minute jogging between the intervals.

Resting (rather than jogging during the rest period) enabled the runners to work harder and spend more time at peak VO2. This is the whole point of interval training, to spend more time running in the 90-100 percent VO2 max region. The rest allowed the runners to suffer more. Perceived effort by the runners after each run was also lower with rest in between. The researchers concluded that complete rest is preferable for this type of workout. 

Some points to note. The runs were done at identical running speed. The runners may be able to run faster if they were allowed to run the interval at their own pace with a jog recovery since jogging (low intensity exercise) keeps the blood flowing, which eliminates lactic acid quicker to enable you to go faster at the next rep).

Lactate (or lactic acid) levels were only measured after the workout was over, lactate levels were significantly higher (6.93 vs 6.24 mmol/ L) while the runners rested. 

The question I'm pondering on is whether to make your workout harder or easier? Is standing still to rest better since your muscles are filled with lactic acid and you get to practice running in that state? 

Or is jogging better since you can train your body to eliminate lactic acid quicker form your bloodsteam and thus enabling you to run faster. Perhaps, you can do complete rest while training for your next race this year and do the jogging rest for the same race next year and see which gives a better race timing. Definitely a good study topic for researchers.

If your goal is to run each rep as quickly as possible, then you are better off resting or just walking a little, if the recovery time is a minute or under since resting helps to restore phosphocreatine, which fuels your sprints and the starting stages of your longer runs. (This is why some athletes that require frequent sprints in the sport - hockey, basketball, football etc take creatine) which can be a separate post. 

However if your rest period is 2 minutes or longer, light jogging may possibly help you run faster since you are actively clearing lactic acid and other metabolites.


Reference 

Sanchez-Otero T, Tumil JL, Boullosa D et al (2022). Acive Versus Passive Recovery During An Aerobic Interval Training Session In Well-trained Runners. Euro J Appl Physiol. 122(5): 1281-1291. DOI: 10.1007/s00421-022-04926-2.

Monday, July 11, 2022

Viscosupplementation (Gel Shots) For Your Knees?

Picture from whichmedicaldevice.com
Many of our patients have been asked to do a hyaluronic acid injection when told that their knees were "worn out" due to osteoarthritis.

Hyaluronic acid injections (also commonly known as gel shots) are thought to help with restoring the joint fluid (synovial fluid) composition to help with lubricating and providing shock absorption to the joint. They are often suggested for patients with mild to moderate osteoarthritis to alleviate pain, reduce friction and hopefully delay surgery (total knee replacement).

The following paper is a *systematic review and meta-analysis of the largest collection of randomised trials of whether hyaluronic injections are helpful for knee osteoarthritis.

169 trials involving 21,163 patients were first identified through searches from Medline, Embase and Cochrane Register of Controlled trials. Only randomised trials with more than 100 participants per group comparing viscosupplementation with placebo or no intervention were accepted. Patients were usually given a single course of 2 to 6 injections.

Of these, 24 large, placebo controlled trials (8997 randomised patients) were included in the main analysis found that viscosupplementation (or using hyaluronic acid injections) offered a small but strong conclusive reduction in pain intensity compared with a placebo injection. 

This translated to a margin of 5 mm on a 100 mm visual analogue pain scale (or half a point on a scale of 0-10). That's a really tiny pain reduction in my opinion.

However, based on 15 large, placebo controlled trials (6463 patients), viscosupplementation was associated with a statistically significant higher risk of serious adverse events compared to a placebo.

Serious adverse events were defined as resulting in hospital admission, prolonged hospital stay, persistent or major disability, congenital abnormality of offspring, life threatening events or death.

Hence, the authors of this systematic review concluded that the findings do not support the use of viscosupplementation for the treatment of knee osteoarthritis.

Still keen on getting a hyaluronic acid injection? Mark Philippoussis (nicknamed "The Scud" after the scud missile), was a former professional tennis player known for his awesome serve. He famously used hyaluronic acid injections every 6 months for his knees to enable him to keep playing after 3 knee operations. 

But he was a former professional who was a finalist in the 1998 US Tennis Open and 2003 Wimbledon Tennis tournament.


Reference

Pereira TV, Juni P, Saadat P et al (2022). Viscusupplementation For Knee osteoarthritis: Systematic Review And Meta-analysis. BMJ. 378: e069722. DOI: 10.1136/bmj-2022-06972

*A systematic review meta analysis is a search aided by computer looking for all randomized and clinically controlled studies while a meta-analysis means using statistics to combine the data derived from a systematic review. 

Sunday, July 3, 2022

Higher Cadence Cycling Slows You Down?

Stage 2 by Tim de Wale/ Getty images from The Guardian
The most important of all cycling races, the Tour De France (TDF) 2022 started on Friday night in Denmark. Cycling fans worldwide will no doubt be following the race as it unfolds. I definitely am.

Mere mortal cyclists (myself included) often like to copy what the pros do. Ever since the Lance Armstrong era, high cadence cycling or riding in excess of 90 revolutions per min (RPM) became popular. 

With his superb spinning of the pedals in the 2001 TDF he attacked and dropped Jan Ullrich in the memorable stage at Alpe d'Huez (watch from 0:27 min) on his way to victory on that stage and overall victory.

Probably from then onwards, new cyclists and recreational cyclists often believe that faster pedaling is always better. 

However, a published study concluded that amateur cyclists do not get any added benefits from high cadence cycling. In fact, it actually tires you out, especially when you ride at high intensities.

The researchers studied a group of recreationally active men and women and had them pedal hard to to ventilatory threshold (the intensity when breathing becomes laboured). Cadences between 40 to 90 RPM's were used. Heart rate, pedaling forces, thigh muscle oxygenation (amount of oxygen needed by thigh muscles to make the energy needed to keep pedaling) were all measured.

As the subjects pedaled faster, the force generated with each pedal stroke decreased. Since your muscles contract more frequently and less intensely, force generated will drop. This makes you fatigue less and helps you to recover quicker, especially while climbing. 

However in the study, the subjects' heart rate increased, meaning this required more energy, making it less efficient. At 90 RPM, their heart rate increased by 15 percent, their efficiency decreased while muscle oxygenation dropped. 

The authors concluded that this shows that pedaling at higher cadences is inefficient for recreational cyclists. This is due to wastage of energy trying to stabilize themselves while coordinating their pedaling at higher RPM's than what they are used to. 

Try it when you next get on your bike (although trying on a stationary bike may be safer) and pedal very fast at low resistance. You may be wobbling all over the saddle and your postural and stabilizing muscles will be working hard to minimize your wobbling. This leads to more work done and higher oxygen demand overall. 

Different cyclists can ride at the same speed whether they are pedaling 60, 90, 100 RPM or any other cadence. It depends on how much wattage (or work done) produced, how comfortable you are and most importantly, what you can sustain. No point pedaling at a high cadence if you cannot ride for long or far with that. You will not enjoy your ride.

I will add that the study did not consider the length of crank arms on the bicycle. Crank arm length definitely matters. A shorter crank arm will help you spin faster more efficiently. 

My experience is that if your legs feel tired quicker than your lungs, your gear is probably too heavy and you should shift to an easier gear and increase your cadence. 

If you're breathing too hard and your legs feel fine, you can use a heavier gear and pedal at a lower cadence. Try switching back and forth with the gears and take note of how you feel. This will help you find the right cadence to ride longer and stronger.


Reference 

Formenti F, Dockerill C, Kankanange K et al (2019). The Effect Of Pedaling Cadence On Skeletal Muscle Oxygenation During Cycling At Moderate Exercise Intensity. Int J Sp Med. 40(5): 305-311. DOI: 10.1055/a-0835-6286


Stage 2 in Denmark last night, watch this excellent video from official TDF website.

Picure from www.letour.fr