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 80-100 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 drink. Breakfast 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 depleted. There was 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 water, sugar 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.

You Definitely Do Not Need Extra Sodium Supplementation, Not Even In Hot Conditions

A few weeks ago I wrote about why it is not necessary to consume sodium to prevent muscle cramps. That post was popular as many runners shared it.

Well, here's further proof and confirmation that you do not have to consume sodium, even in a long ultra marathon.

Researchers found that majority of ultra runners (66 percent) in a race feel that sodium supplements should be made available at aid stations to prevent hyponatremia  and muscle cramping.

Previous research shows that consuming extra sodium does not prevent cramps, dehydration or nausea. Findings actually show that excessive sodium consumption can lead to the extra sodium left as residue on your skin and clothes. This is commonly seen as a white deposit left on your skin especially after a long training session or race.

After you consume too much sodium, it may lead to drinking too much water causing hyponatremia. Trust me here, as I'm guilty of this actually. I spent 2 days in the intensive care unit of a Hong Kong hospital when I had hyponatremia during a 100 km race in November 2000.

The researchers also found that a typical race diet (sports drinks, gels and bars) will usually provide enough sodium for your needs. Moreover sodium itself is not a source of fuel that can help sustain your efforts.

The researchers concluded that that study showed that no sodium supplements are required for ultra marathons in hot conditions lasting 15 to 30 hours (Hoffman et al 2015).


References

Hoffman MD et al (2015). Sodium intake During An Ultramarathon Does Not Prevent Muscle Cramping, Dehydration, Hyponatremia, Or Nausea. Sp Med Open. 1(1): 39.


Hoffman MD  and White MD (2019). Belief In The Need For Sosium Supplementation During Ultramarathons Remains Strong: Findings From The Ultrarunners Longitudinal Tracking (ULTRA) Study. Appl Physiol Metab. DOI: 10.1139/apnm-2019-0238.

Sports Drinks Cannot Replace Your Sodium Levels During Exercise

Gatorade- thirst quencher, but can it replace your sodium levels?

Last week I wrote about what causes muscle cramps. I also said I will write about why the Sports drink/ fluid replacement companies are inaccurate in telling us that sports drinks like Gatorade, Powerade and Endurox etc can replace electrolyte losses.

When you sweat, your electrolyte levels begin to rise! Yes, you read correctly. Let me explain more.

Let's say you have five cups of water and five teaspoons of salt in your system. If you remove one cup of water and a teaspoon of salt, the balance remains the same. There is a teaspoon of salt for every cup of water (i.e. a concentration of 1.0).

Now if you lose 2 cups of water (like when you exercise) and a teaspoon of salt, you've lost more water than salt. The concentration of salt has now risen to 1.25. Your salt (and electrolyte) levels are now higher and will remain higher as you become more dehydrated.

Apply this concept to our physiology. Our sodium (salt) concentration of blood is about 140 mM (or 3.2 grams of salt in every litre of blood). Our sweat has a sodium concentration between 20-50 mM. So even for "salty sweaters" (people who lose more salt than others when they sweat), they lose about 1.1 grams of salt max in every litre of sweat.

Thus, the theory that muscle cramping is caused by low electrolytes as a result of sweating cannot be true. You definitely lose more fluid (or water) than sodium when you sweat.

Sports drinks are incapable of maintaining your body's sodium levels during exercise despite what the manufacturers and advertisers tell you. The sports drink industry has created a perception  that its electrolytes that will help prevent a decrease in sodium.

As explained above, sweating does not decrease your sodium levels, it causes an increase in sodium levels. Sports drinks actually contain insufficient sodium to counteract the effects of sweating on the blood's electrolyte concentration. In fact it causes your sodium levels to fall further.

A sports drink usually contains approximately 18mM of sodium (or 0.4 grams of sodium per litre). That means if you drink a litre of Gatorade (or 100 plus, Powerade etc) during exercise, you can replace a litre of fluid, but only 0.4 grams of sodium.

Blood normally has 1.4 grams of sodium per litre, so even a sports drink replaces more water relative to salt and will only lower your sodium concentration. You CANNOT elevate or even maintain your sodium levels by drinking a sports drink. It is impossible.

Of course if the alternative to sports drink is water, then sports drinks can help prevent sodium levels from falling further.

The key point is that a sports drink will still cause a decline in sodium levels, though less compared to water.

The act of drinking is what causes the reduction. To prevent your sodium levels for dropping further, you're better off not over drinking in the first place.

It's better to listen to your body and obey what it suggests you to do.

Now you know.

References

Science of Sport - Sports drinks, sweat and electrolytes Part 1

Science of Sport Muscle cramps Part IV

Dugas J (2006). Sodium Ingestion And Hyponatraemia: Sports Drinks Do Not Prevent A Fall In Serum Sodium Concentration During Exercise BJSM. 40: 377. DOI: 10.1136/bjsm.2005.022400.

Sports drinks we have in Singapore

If I have to, I prefer Pocari- "tastiest" to me