It is well known that exercise exerts a stress on the body, increasing heart rate, blood pressure, and also activating the nervous system response that increases the number of white blood cells found in the blood 1, 3. These immune cells are involved in fighting pathogens that make us unwell, including colds and flus that are common in colder months. The immediate increase in number of these defensive immune cells often quickly disappear from circulation within a few hours after exercise, with researchers unsure of where these cells were trafficking too. Recently, it has been thought that the increased availability of these cells after exercise are more readily trafficked to tissues that require defence from harmful stimulus, and therefore can help fight off infection and strengthen our immune response to sickness 1, 2, 3.

yourself up with a short circuit in the gym of moderate intensity cardio (10min jog/cycle) followed by some controlled resistance exercise moves (3 exercises, 3 sets, 15 reps ea. at 60-70% intensity). After 15mins if you're feeling more energetic, continue the training session and maybe push it a little bit harder, but don't overdo it. If, after 15mins, you're feeling worse, move onto the stretching mats and pat yourself on the back for walking through the doors and warming your body up anyway. 15min of moderate intensity exercise and 10mins of stretching will be enough to increase the availability of your immune cells to help you combat sickness, and motivate you to prevent derailing your fitness and strength progress this winter!

1. Lancaster et al., Exercise and the immune system: implications for elite athletes and the general population, Immunology & Cell Biology, 2015, 94, pp. 115-116.

2. Walsh NP, et al., Position Statement Part one: Immune function and exercise. Exercise Immunology Review, 2011; 17, pp. 663.

3. Pedersen BK, Hoffman-Goetz L. Exercise and the immune system: regulation, integration, and adaptation. Physiology Review, 2000; 80, pp. 10551081.