IMMUNITY IN NUMBERS

70%

The proportion of athlete illnesses that result in a serious disruption of training, according to the Journal of Sports Medicine.

5–10%

The sensible weekly increase in training volume recommended to avoid weakening the immune system, according to a review published in the European Journal of Sports Science.

30-60g

The recommended amount of carbs consumed per hour of exercise to limit any impairment of the immune system, according to the Journal of Applied Physiology.

33%

The reduction in the duration of cold symptoms caused by taking zinc lozenges, according to researchers from the University of Helsinki.