Posted on May 20, 2016 by Jenny Cromack
Exercise symbolises health, fitness, and well-being but when is it too much or when should we tone it down a little? I often get clients coming to sessions with illnesses or ringing to ask if they should train. My advice is always listen to your body, it will tell you, but this article focuses on exercise and the immune system – what exercise does for the immune system and when it may be a hindrance to our health.
It has been shown that recreational exercisers working through a structured program of progressive intensities, with rest days programmed into it may actually experience a boost in their immune system compared to the sedentary population.
What is interesting is that endurance and elite athletes who’s exercise schedules are very overloaded and their opportunities for rest are very limited experience a suppression of their immunity and actually put themselves more at risk of getting illness, such as colds and fevers, than the sedentary population.
When is it too much?
Some studies have suggested that moderate to high intensity workouts which last longer than 1.5 hours without refueling during the session put people at risk of immune system suppression. This is heightened if there is inadequate rest days between workouts.
Why does it happen?
Exercise stimulates the release of hormones such as adrenaline and cortisol. These are stress hormones which cause a suppression of the immune system and temporary (after exercise) drop in the cells associated with the immune system. If the immune system is temporarily hindered and insufficient rest is allowed between sessions it will not be given the time to recover and perform optimally. This will result in you being more prone to contracting illnesses and taking much longer to combat them.
Outdoor exercise can allow pathogens in, and in combination with breathing hard stressing the airways can leave you prone to these diseases. Also, without sufficient nutrition and fueling of the body the immune system is not energised to combat these diseases.
What should I do?
The best way to prevent any counter-productive effects of regular exercise would be, in my opinion, to do the following:
- Structure rest days into your plan; allow 24 hours between heavy sessions
- Keep amino acid and electrolyte levels up during intense workouts; replace those nutrients that are key for immunity
- Keep a balanced nutrition routine; ensure you are fueled with the best foods to fight of illness
- Listen to your body; don’t train if you are already feeling ill and run down it will only prolong your recovery
Hopefully this is beneficial in informing you of the possible effects of exercise on the immune system and allow you to make the decision to train or not to train when you aren’t feeling 100%.