OK so Tim and his Science in Sport chums might have a vested interest in getting you to swill down their products as often as possible, but you can’t deny that everything they’re saying here is true. And it’s even got a heart warming story. Aaaaaaah!
Last Weekend we had a guy on our training run that developed such a transmission problem (snapped chain beyond repair) that we needed to push him the 20 or so miles home.
During the time spent hanging around fixing punctures and trying to piece together bits of chain, it was that kind of run. Many of the guys were getting very cold – one guy was so cold he was having trouble keeping up, even though 4 of us were taking it in turns to push our transmission-less team mate.
I had a spare Go gel so I gave this to our cold friend who quickly came around, and was even able to contribute towards the pushing at the end of the ride. Food not only provides energy for keeping you going on the bike, but has a “specific dynamic action” or “thermic effect” – basically the metabolism of food will warm you up. Between 10 and 30% of the ingested food energy is converted to heat energy in the body. If you just need to get warm just about any kind of food will do the job, but if you are planning on keeping exercising then a carbohydrate energy bar or energy gel is probably most appropriate. So make sure you take out extra gels and energy bars when the temperatures are falling
With all this cold weather it is also tempting to think that you do not need to drink, especially when it is difficult to do so with gloves on, and in the case of last weeks ride in -5degreesC your bottles freezing.
However, not only are you likely to put more clothing on, so that sweat rates may be just as high during winter training in the cold as they are in the summer (if you doubt this just try weighing yourself before and after a long training ride, any differences in weight are almost certainly due to fluid losses), but additional fluid losses also occur via the respiratory tract.
When cold air is breathed in it is warmed up, so even though you may be breathing in air which is several degrees below zero, it usually reaches between 26 and 32 degrees C before it reaches the bronchi. This prevents cold damage to the delicate parts of the lungs, but the increase in temperature also increases the capacity of the air to hold moisture, quite often you can see this moisture when you breath out. This additional fluid loss can result in a dry mouth, burning throat and general chest irritation – all of which can contribute to the discomfort of riding in the cold. These fluid losses can be reduced by wearing a mask or balaclava, but you do need to ensure that this does not act as an additional deterrent to fluid and energy consumption. Probably the best solution to drink is a carbohydrate electrolyte solution like Science in Sport GO -if you make it reasonably strong -8% solution (80g in a litre)not only will it provide a significant amount of energy but the carbohydrates and salts will help prevent your bottle from freezing!
For more Reading try, McFadden ER, Respiratory heat and water exchange; physiological and clinical implications. J. Appl. Physiol., 54:331, 1984
For more info. try www.scienceinsport.com.