Anyone that works with the public will know that this year has been a particularly brutal one in terms of colds and influenza. With the new year upon us we are trying to lead healthier lives, keep resolutions, and ride the wave of enthusiasm that a new year can bring. Becoming more active, whether that means hitting the gym three times a week, taking up a new sport, or just getting out regularly to go for a walk – we don’t want to lose the momentum. So the question comes up: can I keep exercising when I’m sick?
General consensus is that if symptoms are of the common cold variety, then regular training can resume shortly after symptoms subside.1,2 When you are fighting an infection your performance is poorer, and the benefits you may derive from the exercise would be diminished. So, as long as symptoms are “above the neck” (ie stuffy or runny nose) exercise is probably safe but don’t push it and stop if symptoms get worse.3 Gentler forms of mild to moderate exercise may help you feel better, such as a brisk walk, and may help you feel less sluggish.
However, if symptoms are systemic or “below the neck”, such as fever, chills, fatigue, swollen lymph nodes, chest congestion, vomiting, muscle aching, then regular high intensity training should not resume for 2-4 weeks to reduce the risk of viral myocarditis, valvulitis, etc. Training with a fever, you risk heat stroke and heart failure. When resuming exercise, make sure you start back at a lower intensity.
Some epidemiological studies have shown that individuals who
partake in marathon events or very heavy training are at increased risk of developing a respiratory tract infection.4 They determined that running more than 96 km/week doubled their odds of getting a cold compared to those that trained no more than 32 km/week. Later epidemiological studies supported these findings.5,6,7 The risk is highest, it appears, in the one to two weeks after marathon races.
The immune system is very complex, consisting of several components, so the idea of boosting it with a single supplement is misguided. At this point in medical research, the best way to boost an immune system should address all aspects of a healthy lifestyle including getting enough sleep, managing stress, eating well, quitting smoking and exercising moderately. Regular exercise improves cardiovascular health, and by promoting good circulation can improve your ability to fight infection; however, when you are fighting an infection is not the best time to push yourself.
This information is not intended as a substitute for medical advice. Always seek the advice of a medical professional when exercising during or after an illness.
- Nieman DC, Nehlsen-Cannarella SL. Effects of endurance exercise on immune response. In: Shephard RJ, Astrand PO, eds. Endurance in sport. Oxford: Blackwell Scientific Publications, 1992:487-504
- Nieman DC. Exercise, infection, and immunity. Int J Sports Med 1994;15: S131-4 1.
- Eichner ER, Infection, immunity, and exercise. Phys Sportsmed 1993;21(1):125-135
- Nieman D, Johanssen LM, Lee JW, Arabatzis K. Infectious episodes in runners before and after the Los Angeles Marathon, J.Sports Med Phys. Fitness. 1990;30:316-328
- Peters EM, Bateman DE. Respiratory tract infections: an epidemiological survey. S.Afr.Med 1983;64:582-584
- Peters, E. M.: Altitude fails to increase susceptibility of ultramarathon runners to post-race upper respiratory tract infections. S. Afr. J. Sports Med.1990; 5:4-8.
- Peters, E. M., J. M. Goetzsche, B. Grobbelaar, T. D. Noakes: Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runners. Am. J. Clin. Nutr.1993; 57: 170- 174
- Matthews CE , Ockene IS , Freedson PS , Rosal MC , Merriam PA , Hebert JR. Moderate to vigorous physical activity and risk of upper-respiratory tract infection. Med Sci Sports Exerc 2002; 34(8):1242-1248