Here is another study the undercuts your excuse of not having enough time to workout. In a small but compelling study, researchers have demonstrated that as little as 13 minutes of weight lifting three times per week increases a participant’s strength to the same degree as doing 70 minutes of weight lifting three times per week. They key is lifting to failure through eight to twelve repetitions through seven common weight exercises. Participants who performed more reps did have greater bulk of muscle but not greater strength. One conclusion that we all know: “A lot of people probably do not push themselves that much” when they workout says the lead author of the study. For this approach to work, you must lift to failure, meaning “you must strain the working muscles to limp exhaustion by the end of each set…”. This work builds on other studies showing that great gains in performance can come from short high intensity workouts. But you must push yourself!