Every time I go to the gym or do exercise I see people doing their sets and then resting without having an idea of how long. As soon as they think their body feels ok again, they are onto their next set no matter what the intensity.
What people forget is that you obviously want to get the maximum out of your time at the gym. Otherwise what’s the point in going? The fact is that you want to do the least you can, and get the best results possible.
Something as simple as timing your rest between sets, exercises, or running time is very important in terms of the energy system, and type of muscle that you want to improve.
How long should I rest?
- 20-60 second rest – more for muscular endurance. This should be used when doing your 12-15 rep max.
- 1-2mins rest – more for gaining muscle bulk, and getting toned. This should be used when doing your 8-11 rep max.
- 2-3 mins rest – should be used when trying to gain muscle strength. should be used when doing 4-6 rep max
- 3-4 mins rest – should be used when trying to develop muscle power (speed + strength) should be used when doing 2-3 rep max
- 5 mins rest – should be used when trying to develop muscle power (speed + strength) should be used when doing 1 rep max
The fact is that when doing different repetitions/working out for different periods of time, different energy systems are being used. These different energy systems take different lengths of time to fully recover. There fore it is important to know which energy system/what you are trying to achieve when working out, to aim your rest period at this.
There are 3 main energy systems that you body uses during exercise –
ATP-PC (adenosine triphosphate phosphocreatine system) – Phosphorcreatine is broken down into adenosine triphosphate and phosphate. When they split they release energy. It is responsible for the first 10seconds of energy in intensive sport. It takes around 5mins for all of the ATP-PC to restore (this is why you should take 5mins rest when doing your 1rep max). This is an anaerobic system.
Glycogen system – Glycogen that is stored in muscles is broken down into energy and lactic acid. This is responsible for 10seconds – 2 mins of energy. This is an anaerobic system.
Aerobic system – with the use of oxygen, glucose is broken down into energy, carbon dioxide and water. The system will first use carbohydrate in the body, then fats, and finally protein to make energy.
- 3-5 mins rest – using ATP-PC (adenosine triphosphate phosphocreatine system) system. (anerobic)
- 2-3mins rest ATP + Glycotic systems (anaerobic)
- 1-2 mins rest ATP+ glycotic system + aerobic system
- 20-30 seconds – aerobic system
Reps and muscle fibers
The number of reps that you do is the decider into how long your rest should be, which muscle fibers you as using and which energy system.
There are 2 main muscle fiber types.
- Slow twitch (type 1)
- Fast Twitch (type 2a + 2b)
The number of reps you do and the length of rest you take will have an effect on which fibers you use.
Slow twitch primarily uses aerobic energy systems and are your endurance fibers.
Fast twitch type 2a use anaerobic and aerobic systems, and type 2b use aerobic systems.
Your genetics will decide on the distribution of the number of these fibers in your body.
It is not possible to gain any more of them, but it is possible to improve the quality of them.
- 12+ reps – slow twitch
- 8-12 reps – slow twitch and fast twitch, mainly type 2a
- 4-8 reps – mainly type 2a and some 2b
- 1-3 reps – type 2b
The overall conclusion of this is to say, it doesn’t matter how hard you train, or what you train for. If you take 5 minutes to set down what you are trying to achieve, and follow the rules, you will get far more out of your training.