Why Do We Need To Rest?
As we all may know the body has 3 main energy systems to create the output of physical activities. These systems will almost always overlap one another no matter the workout intensity or length. Here I'm just going to explain what the energy systems are and how they control our workouts.
All Systems Go!
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.
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.
- So you get the idea as to how the energy systems work and which ones contribute to which factors of exercise.
Why Should I Know This?
You should want to know this as it will help you plan your workouts more effectively. You can now look more in depth at how long your rest pauses should be. Loads of people always ask "How long shall I rest between sets?" Here's my answer:
2-4 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 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: Personally I love taking shorter rest periods in between sets no matter the goal, its just a preference of mine. So 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.
See my HYPERTROPHY explanation page if you're struggling with understanding this.
For accurate resting times please keep a timer on your phone or stopwatch whilst in the gym, I do this every workout and have observed its effectiveness rise brilliantly. Don't over or under time your rests.