Better Than Before: What I Learned About Making and Breaking Habits--to Sleep More, Quit Sugar, Procrastinate Less, and Generally Build a Happier Life

by Gretchen Rubin

and make one or two trips to a cardio gym for forty undemanding minutes split between the StairMaster and the stationary bike. Once a week, I do push myself hard, in my work-to-failure strength-training session; it’s extremely challenging, but it lasts only twenty minutes, so I can stand it.