Tips for running in warm weather at the Standard Chartered Mumbai Marathon: Part 2

Now that we are done with the tips to exercise in the heat and the physiological responses of it, the next thing to know is the Hydration Guidelines.

In case you missed Part 1, click here.

Hydration Guidelines

Once your overall fluid volume needed is determined from the above weighing, experiment with training your stomach to tolerate greater fluid volumes at regular intervals. For instance, if 900 ml per hour is your ideal volume, try consuming 300 ml every 20 minutes as compared to 150 ml every 10 minutes. By practising in training, it’s possible to teach the body to tolerate greater fluid volume less frequently and support faster gastric emptying.

According to Dr Noakes (in his extract on Temperature Regulation during Exercise), drinking more fluid less frequently speeds gastric emptying (the movement of fluid from your stomach to intestines).

This is so because it has been observed that as fluid volume increases, gastric-emptying rate also increases, allowing the small intestine to be more proficient at absorbing and delivering essential fluids, carbohydrates and electrolytes to the body. Ingesting the appropriate fluid volume may be more valuable than the actual timing.

Lastly, due to the fact that your pace is likely to feel ‘hard’, you will perhaps end up running at a higher percentage of your max heart rate. This means that your body is working hard to maintain this pace and you will also burn carbohydrate faster in the heat, especially in your long run. It is advisable to also take in some carbohydrate with water on the day of your long run, if you want to finish it comfortably.

Sodium Losses

What about salt? Research confirms sodium loading before exercising in the heat supports fluid balance and endurance during exercise.

Sodium (Na) ingestion is beneficial during a run because it stimulates thirst and helps to replace electrolyte losses from sweat. Failing to take adequate sodium after running hinders the return to a state of normal hydration.

Sodium loss is harder to assess than fluid loss. On an average the sweat of a fit but unacclimatized runner contains about 2.3 gms of sodium per litre. Hence, if you were to calculate the amount you sweat per hour, you could estimate the amount of sodium loss. On a qualitative scale, a grainy texture to the face and skin, a white sweat ring on clothing, and sweat-saturated clothes are signs of high sodium losses after a run. Inadequate sodium may also be the culprit behind nagging muscle cramps. These recognizable signs of greater sodium losses warrant a little extra sodium in the diet.

Running Attire and Training Alterations

Warm weather necessitates that you wear clothes that ‘breathe’, drink about 150-200 ml of water every 15 mins, run (if necessary, walk in between) at a pace that feels comfortable, sponge your neck, arms and shoulders to keep the skin cool and wear a cap to keep radiant heat off the head.

Conclusions and suggested strategy: Based on the physiology of exercising in the heat, there are some key take-ways that can help in the Standard Chartered Mumbai Marathon race.

1. The most important thing is to adjust your pace. Steve Sisson, assistant coach of women’s cross country and track at the University of Texas, encourages his athletes to adjust expectations and change their attitudes. He explains, “Heat really affects intensity. Adjusting the level of effort or intensity based on what the body is signalling is a key lesson for any athlete to learn.”
2. Hydrate well based on your fluid requirements and you are well-advised to check your specific fluid requirements by running a sweat rate test on yourself as indicated above. Use this to regulate your fluid intake during the race.
3. Provide for carbohydrate intake by taking in Gels or a snack. The approximate guideline is 60 gms / hr of running.
4. Lastly, electrolyte loss has to be made good thru’ taking in an electrolyte or a Gel, besides drinking plain water.

Researched and compiled by Daniel Vaz

Bibliography and suggested reading:

1. Susan M. Shirreffs; Symposium on ‘Performance, exercise and health’; Hydration, fluids and performance – School of Sport and Exercise Sciences, Loughborough, UK.
2. Dr T Noakes; Temperature Regulation during exercise
3. Preventing Dehydration: Sports Drinks or Water

Published with permission from Dumbelled.com.