Energy and Fatigue Archive

Q. What is better for my heart—a fast run on the treadmill for 10 minutes or 30 minutes of light cycling on a machine?

A. The benefit of exercise on heart health depends on the dose; in other words, the more the better. So, my answer to your question is "Why not do both?" Exercise of virtually any kind prevents heart attacks, strokes, high blood pressure, and diabetes.

Strength or resistance training challenges your muscles with a stronger-than-usual counterforce, such as pushing against a wall or lifting a dumbbell or pulling on a resistance band. Using progressively heavier weights or increasing resistance makes muscles stronger. This kind of exercise increases muscle mass, tones muscles, and strengthens bones. It also helps you maintain the strength you need for everyday activities — lifting groceries, climbing stairs, rising from a chair, or rushing for the bus.

The current national guidelines for physical activity recommend strengthening exercises for all major muscle groups (legs, hips, back, chest, abdomen, shoulders, and arms) at least twice a week. One set — usually 8 to 12 repetitions of the same movement — per session is effective, though some evidence suggests that two to three sets may be better. Your muscles need at least 48 hours to recover between strength training sessions.