“Mr. Zickerman’s program is essentially training with weights, ‘the way to go for young and old alike.’ What may differentiate it from some other similar regimens is the slowness of the movement of the weights. His method slows movement to a 10-second cadence, 10 up, 10 down. ‘We don’t stop at the top or bottom, so our muscles sustain a constant steady load for about five to eight repetitions,’ he writes, adding that such an exercise ‘fires the muscle fibers’ deeply and builds lean muscle mass. By comparison, he adds, aerobics ‘builds virtually none.’ He makes a convincing case.