For the maximum health benefit, should I devote more exercise sessions per week to weight training or to aerobics?

Strength training has many benefits for health and well-being, but it doesn't train your heart and lungs. For that essential piece of the fitness picture, you need aerobic exercise. Conversely, aerobic exercise won't make you strong. If you are trying to stay fit by only doing aerobic exercise, the ultimate irony would be living to an old age with a healthy heart only to find yourself too feeble to remain independent.

It is essential to strike a good balance between strength training and aerobic exercise to make a healthier you. A good general rule of thumb is to get a minimum of 20 to 30 minutes of vigorous aerobic activity three times per week and 20 to 30 minutes of strength training twice a week.