When you’re working out, the amount of weight and number of reps are all important, but one factor that’s often forgotten is rest. In the big picture, rest days are important because they allow your body to recover from the mild damage to your muscle fibers that normally happens during a workout. But in the short term, adding rest into your rep-and-set scheme allows your body to recharge so you’re ready for your next set.
Your work:rest ratio is the comparison between how much time you’re (working) lifting weights or doing high-intensity cardio to the amount of time spent resting. So, if you’re doing 10-second sprints and resting for 60 seconds, your work:rest ratio is 1:6. The ratio should vary based on the type of training you’re doing. It’s typically higher for high-intensity or aerobic training for cardiovascular and muscular endurance, and lower for anaerobic training for strength and power.
Anaerobic training for strength or power
For resistance training where your goal is to build muscular strength or power, aim for a work:rest ratio between 1:3 and 1:6. For example, if it takes you 20 seconds to perform a set of 8 reps, you’ll want to rest for somewhere between 60–180 seconds (1–3 minutes) before you begin your next set. Longer rest periods closer to 5 minutes are appropriate when lifting high percentages of your 1-rep max. Work:rest ratios for sprint training (short runs at full speed) should be similar, clocking in between 1:3 and 1:8. So, for a 30-second sprint, you’ll want to rest for 1.5–4 minutes, depending on how much sprint work you’re doing and your workout goals.
Aerobic training for endurance
For resistance training where your goal is to build muscular endurance, your work:rest ratio should be lower than for strength training, close to 1:1. For example, if your set of 12 reps takes 30 seconds to complete, you’ll want to rest for about 30 seconds between sets. For building endurance of a single muscle group, rest for less than 30 seconds. The ratio for cardio workouts where you run more than one minute are similar. So, if you do a 400 m run in 2 minutes (which should be at a slower pace than your 30-second sprint), your between-set rest should be 2–6 minutes.
High-intensity training should take less time than traditional strength and endurance training. The shorter duration comes with a higher work:rest ratio of about 1:1 (and no more than 2:1). Work:rest ratios much higher than 2:1 start to become extreme conditioning programs, which can lead to career- and life-threatening injuries.
Ratios for working individual muscles
You can apply the principles described above to individual muscle groups too. So, if you’re doing a full-body endurance circuit, work in that 1:3 work:rest ratio for each muscle group by exercising a different group during the rest period. For example, doing 10 seconds of body squats, 10 seconds of push-ups, 10 seconds of pull-ups, and a 10-second rest period before repeating the cycle gets a 1:3 work:rest ratio for each muscle group (10 seconds of squats followed by 30 seconds of “leg rest”). Repeat a 4-exercise cycle 2–3 times, and then take a longer rest period between sets, and you’ll have successfully built in enough rest during your short workout. If you do include this type of rest into your workout, be sure to include active recovery days in your larger program to allow for better recovery.
Rest within your workout is incredibly important to allow your body to recharge and to get the most out of your workouts. If you’re strapped for time and need to get in a quick workout, rest strategically, don’t cut it out altogether.