We asked our training and nutrition expert Dr. Chris Bartlett to
give us some advice, especially relating to sportives and the long
Alpine routes many of us will be tackling in the coming weeks.
"This past weekend saw thousands of riders compete in the
Marmotte; the 40 ºC heat combined with the huge physical exertion
and low air speeds typical of climbing caused many riders to suffer
heat stroke and dehydration.
To give oneself the best chance of coping in such conditions, a
considered hydration strategy needs to be in place. Feedzones are
at designated places, so plan where you will stop
to rehydrate. In such hot conditions, it would be prudent to
Ensure you are adequately hydrated in the days leading
up to the event. Drink little and often to avoid the
potentially severe condition of hyponatremia (low sodium levels in
Sweat rates are typically 1-1.5 litres an hour in summer, but can
reach 3-4 litres per hour in extreme conditions. To maintain
performance, this needs to be replaced.
Water is better absorbed by the body when it contains sugar and
electrolytes. (Molecules of sugar and salts take water across the
intestinal walls as they pass through). So for high rehydration
rates, use energy drink.
In such hot conditions, overheating can become a real danger.
Body temperature can go over 40 ºC, and cause real damage.
DO pour water over your self to help with cooling
(if it is in ample supply, i.e. drink first!). Floyd Landis used
this to great effect during stage 17 of the 2006 TdF. Taking 90 or
so bidons to pour over his head from his team car. The sole reason
for his 6 min solo win."
"Muscle cramp is often not related to dehydration. It is
commonly due to overuse of the neuromuscular system, i.e. to ask
too much from your legs, to ride faster and longer than you have
trained them to do so. If your legs begin to 'twitch', overuse is
likely the cause. It is not likely due to low salt levels; indeed,
people cramping in this way have even been shown to have higher
blood sodium levels. In such cases, there is much anecdotal
evidence to support that sour foods (pickle, Haribo Tangfastics)
alleviate the symptoms. However, If you suffer an all-over cramp,
that is more likely to be due to low sodium levels and consuming
electrolytes will help."