Effect of colostrum on immune function after intense strenuous exercise in well-trained cyclists.

After prolonged, strenuous physical exercise the immune function is impaired
for ~3 to 24 hours (Gleeson, 2007). This causes an *open window* in which a
subject is more susceptible for infections, especially upper respiratory tract
infections (URTI). Bovine colostrum is proposed to counteract this
exercise-induced reduction in immune function. However scientific evidence is
inconclusive so far.

The primary objective of this study is to evaluate the effect of colostrum
supplementation on the immune response after intense strenuous exercise.
The secondary objective is to study the effect of intense strenuous exercise -
and its possible modulation by colostrum - on plasma endocannabinoid levels.

A cross-over intervention study with a randomized, double-blind, placebo
controlled design.

Subjects will either start with colostrum supplementation or placebo (skimmed
milk powder). After a wash out period of 3 weeks the other supplement will be
taken. The colostrum is 12h bovine colostrum supplied by Arts Food Products.
The placebo is skimmed milk powder. From both, the colostrum and the placebo
12.5 gram twice daily will be consumed. After each 10-day period of
supplementation, subjects will undergo an intense exercise protocol to evaluate
the effect of exercise on immune function

Subjects will undergo an exercise protocol twice, once with colostrum and once
with a placebo. The exercise protocol consists of three parts: 1) a maximal
aerobic capacity test, 2) a glycogen depletion part and 3) 1.5h of continuous
cycling. Part 1 and 2 will take place in the evening and part 3 will be done
the next morning. The exercise protocol is severe and is designed to stress the
immune system. The study population (well-trained cyclists) is used to this
kind of exercise - the requested amount and intensity of physical activity does
not exceed their training routine. Therefore, they should be able to complete
the protocol without any problems. Any sign of - gastro-intestinal or
respiratory tract - infection one month before and during the study will be
monitored, and adequate steps will be taken, if necessary.
Blood and saliva will be collected at 4 time-points throughout each
experimental period within a 36-hour time frame. Total blood sampling is ~100
mL per experimental period (200 mL for the entire study). Blood sampling can
give some discomfort and occasionally result in a local haematoma.
Subjects are asked to hold an illness log, a dietary log and an exercise log
during the whole experiment. Dietary guidelines are provided during the run-in
and experimental period.
The supplement used in this study, i.e. colostrum is not expected to have any
serious health effects. Participation in this study does not result in a direct
health benefit. If a positive effect of colostrum supplementation is found,
this could eventually result in the use of colostrum in the nutritional routine
of endurance athletes to prevent symptoms of URTI and other infections.