Building Strength Just Got Faster

If you’ve ever given up on the thought of working out because you didn’t have enough time, turns out that you actually may be able to squeeze in an effective workout in just 13 minutes. A new study finds that a 13-minute workout done three times per week, can improve your strength as much as working out for an hour.

Published in Medicine & Science in Sports & Exercise by Lehman College researchers, the study tested how much time and effort in the gym is needed to make muscles bigger and stronger. In a regular strength-training workout, it is generally advised to complete three to four sets of eight to 12 reps of an exercise, which can translate into an hour-long workout. Essentially, you want your muscles to be very fatigued during the last set to spur the body to begin rebuilding and growing the muscles used.


The study used 34 fit young men and randomly assigned them to three different weight-lifting routines with typical exercises. Group one’s routine was comprised of five sets with 90 seconds in between those sets, for a total workout time of 70 minutes. Group two completed three sets for a total of 40 minutes in the gym, and group three completed only one set, for a mere 13 minutes of gym time. Each of the men worked out three times per week for eight weeks.

The result? Muscular strength and endurance improved equally across the board, regardless of the number of sets performed. However, the men who only did one set were told to lift to failure, meaning going into total exhaustion. Therefore, to get the most benefit from doing one set, you need to lift the heaviest you can for eight to 12 reps to ensure total fatigue.  

Exercises of any kind create small tears in muscles, which is why rest days are recommended. After a workout, “your body repairs or replaces damaged muscle fibers through a cellular process where it fuses muscle fibers together to form new muscle protein strands or myofibrils,” according to Plus, training to failure for your last set can be beneficial according to, because “greater increases in lactic acid in muscle are critical for muscle growth…they trigger increases in intramuscular growth factors.”

To see the best results, you want to keep pushing yourself in the gym to do that extra rep or increase the weight used. The only difference between the three test groups was muscle mass–that is, the men who completed 5 sets had bigger muscle growth than those who didn’t. So if you are looking to grow your biceps or booty, it’s still best to plan for closer to an hour of gym time.

Though this study has yet to be conducted on women or an older population group, it’s something to keep in mind for the next time you want to skip the gym. Even just 15 minutes can help you get a step closer to your goals, so no more excuses!