We posed your question to Dr. Bob Adams, chair of USA Track and Field’s Sports Medicine Committee. Here’s what he had to say:
If it’s above the chest, then basically they can do what they feel like doing. If their ears are stuffed up, their nose, their sinuses, with just a little bit going down the throat, they can cut back a little bit, but usually it’s OK to exercise. They may not feel so great, but usually they can do pretty much what they want to, maybe cut back a bit to a moderate workout of 60 to 75 percent [of their VO2 max].
If it goes down into the lungs or below that, they can’t do their best. They won’t be able to perform, so they need to rest. Maybe just walking around is about it. They need to take it easy. When you exercise, particularly endurance stuff, you’re challenging your immune system. When you have a cold, your immune system is already working as hard as it can. It’s a myth that if you exercise regularly, you’ll have better resistance to infection.
If you have a fever over 100, 101, you shouldn’t exercise, because [the fever] affects your strength, you aerobic power, your VO2 max, endurance, coordination, concentration, your cardiopulmonary output—all of those things are reduced. So the maximum workload is reduced, [making it difficult to see any fitness gains from exercising with a fever]. Your temperature regulation gets messed up, and dehydration becomes a bigger concern because you’re sweating. You need to be sure to get adequate rest and hydration. [Exercising with a fever] can lead to overtraining, you get fatigued, and start this whole spiral down.
The bottom line: If the symptoms are above the chest, athletes can do whatever they feel like, but should consider cutting back on intensity and duration. Chest down symptoms: rest. Fever above 100: rest. As for the idea that raising one’s body temperature by exercising can help kill a cold, “that’s just an excuse people use to keep running when they’re sick,” Adams says.
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