Image Credit: Petranek
It doesn’t take a genius to realize that the more rest you take between sets, the more weight you’ll be able to lift when you do come back. This doesn’t mean that you should always take more rest between your sets… the right amount of rest for you will depend on your goals somewhat.
First off, let’s give little explanation on why you might choose longer or shorter rest periods between each workout. There are 3 different primary energy systems that your body uses to produce ATP, which is the primary fuel your muscles use for exercise.
These definitions come straight from this article on Wikipedia:
ATP-PC System (Phosphogen System) – This system is used only for very short durations of up to 10 seconds. The ATP-PC system neither uses oxygen nor produces lactic acid and is thus said to be alactic anaerobic. This is the primary system behind very short, powerful movements like a golf swing or a 100m sprint. Translation: Best for short bursts of intense lifts, like in power lifting or strength training.
Anaerobic System (Lactic Acid System) – Predominates in supplying energy for exercises lasting less than 2 min. Also known as the Gylcolytic System. An example of an activity of the intensity and duration that this system works under would be a 400m sprint. This is what you’ll partially use for bodybuilding and creating muscle mass, size.
Aerobic System – This is the long duration energy system. By 5 min of exercise the O2 system is clearly the dominant system. In a 1km run, this system is already providing approximately half the energy; in a marathon run it provides 98% or more. You use this when doing aerobic activity, so this system doesn’t really apply to our discussion here.
Now that you have a good idea what these three systems are used for, we can have a discussion about how much rest works best for each goal.
3-5 Minutes Rest: This is useful for trainees who are trying to improve their explosive activities of a short duration. That means that longer rest periods are generally better for people who are training for strength and power and should be used together with lower reps (3-5 reps).
This is because your body requires approximately 3 minutes for it to restore the phosphagen (Creatine Phosphate/ATP) stores for your next set. Once the ATP-PC energy system has been able to replenish the energy stores in your muscles, you’ll be to lift a heavier weight for more reps. So, you should rest longer to get the energy to go heavy.
45-60 Seconds: Taking a shorter rest works better for hypertrophy and building overall muscle mass. The point here is not to lift the most weight you can possibly lift. Your purpose is to keep the stress on your muscles and work them again before they have the chance to fully recover.
This gives your muscles intensity over a longer period of time and allows you to keep your muscle “pump” between sets. This is best for the 8-12 rep ranges used by bodybuilders, and is optimal for increasing muscular mass and hypertrophy.
What about the time in between?
You don’t necessarily have to stay exactly within these rep ranges for building muscle mass or strength. There’s no switch that suddenly gets flipped at 3 minutes where your body suddenly begins to use a different energy system. Your muscles recover gradually while you rest, and each energy system works together and has some overlap.
And as always, this is a highly individual thing. Some people swear by using 60-90 seconds rest while bodybuilding, which can be fine for some people. Each person is a little different, and just as one person can run faster than another, one person can also recover faster than another.
Your recovery time will be influenced by a number of factors:
- The intensity of the set
- How much sleep & rest you’ve had
- Your nutrition
- Your Age
- Any injuries you might have
- The temperature of the room
- If you have a cold or other minor illness
- How intense your day job is
You get the idea. I’m trying to show you that there are so many factors that go into this and that every person’s situation is slightly different. Start with the guides given up above, and adjust them over time as you get to know your body and its needs.