I have observed repeatedly that if I push myself in an aerobic workout, then not just my muscles, but my immune system also takes a beating. My chance of catching a cold is then much higher. I've made this correlation so frequently that I no longer have any doubt there is a connection.
One solution is presumably not to workout too hard, but can this be solved nutritionally? Is there a set of nutrients with which I can replenish my system just before or after an intense workout to counteract the resulting weaker immune system?