As if exercise wasn’t confusing enough — now throw recovery time between sets into the mix. It’s actually an important detail when trying to maximize your results in the gym. However, optimal rest time between sets varies depending upon your fitness goals – building strength or increasing muscular endurance. In general, short rest times between sets are more effective for increasing muscular endurance.
Slow vs. Fast-Twitch Muscle Fibers
Your muscle is made up of slow-twitch and fast-twitch fibers, and most people have about a 50-50 mix of the two. The slow-twitch fibers are involved in muscular endurance, so if you are genetically blessed with a higher percentage of slow-twitch muscle fibers, you already have an endurance advantage. The key to increasing muscle endurance is developing these slow-twitch fibers by exercising with less resistance, higher repetitions and less rest time between sets.
Types of Recovery
There are several types of recovery in exercise, including immediate, short-term and training recovery. Short-term recovery is the focus here, and to speed up your short-term recovery times, it’s all about boosting your muscle endurance. It’s a progressive goal, meaning you may have to start out with the maximum rest recommended and work your way down to less time between sets as your muscle endurance improves.
Rest Between Sets
For bodybuilding, three to five minutes between sets is not uncommon. However, muscle endurance is a whole different bag. Aim for 30 to 90 seconds between sets to increase muscle endurance (source 2). If you’re a beginner, start out closer to 90 seconds and decrease your short-term recovery times a few seconds per week. Another way to look at it is to exercise at a one-to-one ratio of exercise-to-rest (source 3). For example, do squats for 60 seconds followed by 60 seconds of rest.
Sets, Reps, Resistance and Schedule
Increasing muscle endurance means maximizing the number of reps, or intervals, you can do. So, you’ll want to aim for 25 reps per set and no less than nine. Complete two to five sets per exercise. If you’re lifting weights, choose a weight that is about 40 to 70 percent of the maximum weight you can lift for one rep of that exercise – your one-rep max. You can do any type of resistance training as often as every other day. Always be sure to use a slow, controlled motion during each and every rep to maximize its effectiveness — no jerky, out-of-control movements.