[Andy Reed]

Hi CRW

Reviewing the published literature, we know that the risk of illness and specifically URTI increases with both the intensity and the volume of training. It seems like there is a window for up to 12 hours after prolonged or heavy exercise where our immune function takes a dip and we are susceptible to catching colds and flus, so it is going to be tough to avoid illness during the winter months when these infections are much more prevalent, and we are much more likely to get sick during heavy training. As Scott says, it might be preferable to target a fall race for this reason, where you heaviest training loads correspond to the times when colds/flus are just not as prevalent in the community.

In general though:

1. Eat a well-balanced diet to keep vitamin and mineral pools in the body at optimal levels. Although there is insufficient evidence to recommend nutrient supplements, ultra-marathon runners may benefit by taking vitamin C supplements before ultramarathon races. I also think that Probiotics may be of use.

2. Keep other life stresses to a minimum. Mental stress in and of itself has been linked to an increased risk of URTI.

3. Avoid overtraining (ie, training beyond what the body can recover and adjust to) and chronic fatigue.

4. Avoid rapid weight loss (eg, more than 1% of body weight per week, which has also been linked to negative immune changes, especially T-cell suppression).

5. Avoid putting hands to the eyes and nose (a primary route of introducing viruses into the body). Before important race events, avoid sick people and large crowds when possible. Masks may play a role if you are willing to mask up during heavy training blocks.

6. For athletes competing during the winter months, flu shots are definitely recommended.

7. Obtain adequate sleep on a regular schedule. Sleep disruption has been linked to suppressed immunity.

8. Use carbohydrate beverages before, during, and after marathon-type race events or unusually heavy training bouts. These may lower the impact of stress hormones on the immune system.

Hopefully this is useful information.