The winter months are the time of year when people, including endurance athletes, tend to have more illness such as upper respiratory tract infections (URTI). If an endurance runner engaged in heavy winter training should contract an URTI it could mean up to six or seven days of lost training. There are three reasons that the incidences of URTI are more common in the winter months than at any other time of the year, and they include: (1) the general population is inside buildings more of the time and since the virus that causes URTI are distributed airborne there is a greater opportunity for person to person exposure, (2) the colder atmospheric air outdoors creates added stress to the body as it tries to maintain it’s homoeothermic condition, and (3) the less humid winter air dries the epidermal mucous membranes of the body (lips, nose, eyes) and creates small membrane cracking which allows the airborne virus access to the body.
In general, distance runners engaged in endurance training of more than 20 miles per week are much more susceptible to URTI than the general population. Martin et al. showed evidence that running 5-15 miles per week actually gives the immune system a boost (jogging is good for you), but mileage exceeding 20 miles per week deteriorates the immune system in a somewhat linear regression (Figure 1).
Martin showed in his study (Figure 1) that an athlete training at 55 miles per week is seven times more likely to contract an URTI than a runner training at 18 miles per week. This scenario makes it problematic for coaches as they try to keep their athletes healthy and on a progressive training program.
Coaches are capable of many things, but influencing the climate is not one of those things. Nor, is it convenient to isolate the athletes away from people who may be carrying the URTI virus. The emphasis for the coach in preventing the incidences of this type of illness in their athletes should be on practical, habitual rituals that the runners should adopt into their lifestyle.
Check out Coach Christensen’s Preparation of the Elite Junior Middle Distance Runner
Coaches should emphasize to their runners that proper and continued hydration is vital to a healthy immune system. If the body is properly hydrated then the exposed mucous membranes of the body will stay moist. It is important that the athletes do not share water bottles when seeking proper hydration. Since URTI viruses are airborne, they are present on all surfaces such as hands and water bottles. The exchange of water bottles at a critical time following a workout should not be done. All athletes tend to drink more water in the summer. They are generally thirstier and are more aware of regaining water when it is hot. The problem in the winter is that the atmospheric air is so dry that copious amounts of water vapor are lost through breathing as air is exchanged from lung to atmosphere. Because the athlete is not sweating as much as they do in the summer, they think that replacing water is not as critical. Unknown to them is the fact that water lost in air exchange is much higher during winter training than it is in the summer. Distance runners really benefit from licking their lips as they recover from a workout whenever water is lost. Rather than tell them to do so, have them suck on suckers or lozenges post-workout. This act will translate to moister lips and thus no epithelial cracking. There has been some research presented in the last twenty years that suggests the micro-mineral zinc helps prevent colds through a healthier immune system when zinc is added as a supplement. It may, as the research is unclear. Some of the latest research suggests supplemental zinc may not prevent colds, but it may shorten their duration by a couple of days. That alone would benefit the athlete. With this in mind, the coach might suggest lozenges or suckers that have supplemental zinc added. It is recommended that people do not exceed 100 mg of zinc per day, so suggest lozenges or suckers that have 10 or 15 mg zinc.
The last recommendation deals with the athletes lingering outside in the cold air post-workout. Even if it is below 40 degrees F following a long run, the athletes will not feel immediately cold. Their core body temperature is probably in excess of 100 degrees F, and heat is contained in their clothing. They do not feel the urgency to immediately seek shelter. The temperature gradient between the body and the atmosphere at this time is severe. The body does not function well when there is such a temperature gradient. Body cooling under those conditions will be very fast and stressful. The stress will affect their immune system and this will be the moment in time that the virus, if present, will gain a foothold in the cells of the body. Herd them as quickly as possible to shelter. Enjoy the weather!
More winter training advice from Coach Christensen: Winter Development in Cross Country Training
- 1. Martin S, Pierce B and Woods J. Exercise and respiratory tract viral infections. Exer and Spor Sci Rev. 2009;37(4): 157-164.
- 2. Sandstead M. Zinc requirement and the risk benefit of zinc supplementation. J of Tra Ele in Med and Bio. 2006; 20(1):3-18.