How do swimming and jogging compare for burning calories? —G.N., Sun City West, Ariz.

It’s virtually a dead heat. A 155-pound person burns about 280 calories when swimming laps for a half-hour at a moderate pace of 50 yards a minute and about 390 calories at a fast 75 yards a minute. That person would burn roughly the same number of calories by jogging at a moderate 5 miles per hour or a fast 6.7 mph, respectively. Further, swimming typically feels about as hard as jogging at the comparable paces. The two exercises also build strength and aerobic fitness about equally well. Swimming is easier on the hips and knees, but unlike jogging it doesn’t put enough pressure on your bones to protect against osteoporosis.