Thank you for submitting such an intriguing question. This may be a little profound to explain but I will try my best.
We all know that the body takes time to recover after every exercise and logically, high frequency and intensity exercises requires more time. When you do not allow sufficient time for the body to repair, it stresses out. One possible explanation is when your body responds to stress by secreting cortisol (stress hormone) which tide you over this stressful period. However, prolonged cortisol secretion can have detrimental effect which makes you more susceptible to falling sick.
In TCM, Qi is the vital energy behind all physiological activities and chemical reactions, which of course includes the immune system. When you over-exert yourself by exercising excessively, you are actually exhaust your Qi (Yes, too much is no good, which is why moderation is key, sometimes less is more). The deficient Qi will then be unable to defend against pathogens.
What you need to do is get to ample rest, drink more water, have a balanced diet. Wait tilll you feel well enough for the next session.
Wishing you good health!
With regards,
Physician Lee
