Swim. Lift weights. Train in jujitsu. Take long walks. You can choose the means, but the method is a must: You must be active. Get your daily win. Treat the body rigorously, as Seneca tells us, so that it may not be disobedient to the mind. Because as you’re building muscle, you’re also building willpower. More important, you’re building this willpower and strength while most people are not.