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.

How To Beat Muscle Cramps? Sunday Times Article

Sunday Times article 280719

Today's Sunday Times article on training for the Straits Times run says avoid muscle cramps by consuming more sodium? Nah, not totally true. Not at all actually. I've written about this exact same topic way back in 2015.

In that post, I wrote about how renown sports scientist Tim Noakes found no significant differences in sodium and magnesium levels in 72 ultra marathoners among those who cramped and those who did not cramp (Schwellnus et al, 2004). They found that sweating too much had no real effect on muscle cramps.

Try to think of when you last had a muscle cramp? After running 30 km in your marathon or after 3 km in a 10 km race?

Muscular fatigue (or when your muscles get too tired) is what really causes muscle cramps. The muscle cramps so you can avoid injury before you can push yourself further. That the Sunday Times article definitely got correct.  

Muscle cramping occurs mostly during races than during training. If you started your race too fast or you pushed too hard, that may cause your muscle to fatigue and then cramp. Other studies have shown that tough, hilly courses and poor pacing are predictive of muscle cramps.

I also wrote that sports drinks cannot replace your sodium levels during exercise. Your electrolyte levels actually rise when you sweat a lot. Yes, you read correctly. I'll explain this below.

Assume you have five cups of water and five teaspoons of salt/ electrolytes in your body. Say you sweat 2 cups of water and a teaspoon of salt/ electrolytes when you exercise, the concentration of salt/ electrolytes is now higher. It will remain higher as you become more dehydrated.

Apply this concept to our running physiology. Our sodium (salt) concentration 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. Even for a "salty sweater" (those who lose more salt than others when they sweat), they lose about 1.1 grams of salt max in every litre of sweat.

Hence, the theory that muscle cramping is caused by low electrolytes/ salt as a result of sweating is not true. You will definitely lose more water than sodium when you sweat. You can read more of that here.

You read it here first. Now you definitely know.

References

Science of Sport Muscle Cramps Part IV

Science of Sport - Sports Drinks, sweat and electrolytes Part I

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.

Schwellnus MP, Nichol J, Laubscher T and Noakes T (2004). Serum Electrolyte Concentrations And Hydration Status Are Not Associated With Exercise Associated Muscle Cramping (EAMC) In Distance Runners. BJSM. 38: 488-492. DOI: 10.1136/bjsm.2003.007021.

*The Sunday Times article is on page A27 under the Sports section. Go take a look.

Today's Straits Times Article On Hydration

Straits Times article 160917 page C13 under Sport section

Every morning when I pick up the newspapers, I'll usually turn to the sports section first. Today, I happened to look at the article on the training plan for those planning to run the Singapore marathon at the end of the year. "Right hydration integral to a successful race". I thought the article was well written. Fairly straight forward and simple to understand. Also mentioned that over drinking water can lead to hyponatremia.

Wrote about sports drinks. Though you need to know that sports drinks cannot replace or even maintain your sodium levels during exercise or racing.

Just wanted to point out that the two percent loss of body weight (through sweating) during endurance exercise/ racing affecting your performance may not be totally accurate.

I wrote about it before earlier in the year that latest published research suggest that current hydration guidelines may well be wrong.

Two published studies on cyclists and elite male marathoners (including Haile Gabreselassie during 13 major city marathons) showed that weight loss up to three percent did not slow the runners down nor decreased the cyclist's power output.

In fact Gabreselassie lost 9.8 percent of his body weight during the 2009 Dubai marathon and still won the race in 2:05:29 hours! All drinking by the elite runners were ad libitm (or at their own time and pleasure).

Yes I do agree that the quoted study was done on elite runners. How does that apply to us in super humid and sunny Singapore?

My own thoughts are that the sports drink companies definitely recommend us to drink to much. I wrote before that I definitely drink less than my fellow team mates and competitors. From the time I started running cross country as a twelve year old kid to when I was racing triathlons. Even now during my weekly group bike ride. Most of the other cyclists carry two or more water bottles while I survive the three hour ride on one.

In fact I often had a side stitch after drinking while running cross country as a kid. That also deterred me from drinking too much then.

Of course this does not mean you try not to drink at all in your next long run/ ride and especially your next race. What I'm suggesting is that you at least give it a try in your next few long bike or run sessions.  Everyone is different. Try to get through those long sessions drinking as little as you can. You might be pleasantly surprised that you may not need as much fluid as you think.



References

Beis LY, Wright-Whyte M, et al (2012). Drinking Behaviours Of Elite Male Runners During Marathon Competition. Clin J Sport Med. 22(3): 254-261. DOI: 10.1097/JSM.0b013e31824a55d7.

Wall BA, Watson G et al (2015). Current Hydration Guidelines Are Erroneus: Dehydration Does Not Impair Performance In The Heat. BJSM. 49(16): 1077-1083. http://dx.doi.org/10.1136bjsports-2013-092417.