For: Cold survival When: At the start of the season
Those sweat sessions not only fight winter flab but also buff up your immune
system. An Appalachian State University study found that people who exercised
at least 5 days a week took 43 percent fewer sick days due to colds in fall or
winter than their lazier peers. "Every bout of exercise enhances
circulation of key immune cells," says lead author David Nieman, Dr.P.H.
Steady-state cardio or circuit training is best, because rest periods during
interval and strength training may curb the cold-fighting effect of exercise.