Are Rest Breaks Important?

Rest intervals are often overlooked in the set up of a gym program. But the amount of rest taken between sets will change the energy system employed by the body, so, ultimatley, your results.

If you are looking to build power (strength x speed), or pure strength, then relying on the ATP/PC energy system is advised. The initials ATP in this system stand for Adenosine TriPhosphate – the chemical compound that is broken down to release energy for muscle contraction. The PC stands for Phosphocreatine – the comound that very quickly rebuilds the ATP. This system is quick to produce muscular energy for sets lasting 10-20 seconds. The optimum recovery time has long been recommended as 2 to 5 minutes.

If hypertrophy (muscle growth) is the goal, a range of factors will need to be stimulated within the body’s chemistry. Muscle swelling and burning are a couple of many signs that growth factors have been potentiated. Therefore, these sets tend to last more like 30 to 90 seconds and require more of the Lactate and Aerobic Systems. The Lactate System uses muscle glycogen to produce energy, and painful Lactic Acid is the by-product (sounds like something from a Nuclear Power Plant doesn’t it!) So, rest periods of 45 seconds to 90 seconds are more commonly employed.

Lastly, if the goal is to improve cardiovasular fitness or muscular endurance, the working sets may last anywhere from 60 seconds to 5 minutes and beyond. This is because lower intensity exercise is more easily fuelled with oxygen. Think aerobic step classes or sets of 30 and you get the picture. Now, there is usually an overlap of these systems during exercise. Training strength can see improvements in cardio fitness (the left ventricle of the heart thickens, as one example). And training muscular endurance may still see some muscle growth (think long distance swimmers).

Super sets (alternating muscle groups from one exercise to another) can save time and produce more widespread lactic acid, but do accumulate more systemic (full body) fatigue during and between workouts, potentially detracting from set to set performance. Circuit training (numerous exercises performed one by one in a continuous ‘circuit’) is a great balance to target muscular endurance, hypertrophy and aerobic fitness, and can be a great way to save time whilst keeping your heart rate up. Rest periods may be minimal, or non existent. However, due to systemic fatigue, this is probably not optimal for hypertrophy only.

So, this is a simplistic breakdown only. It’s an equation of energy, goals, and lifestyle. At Destiny Health, we recommend:

1) Having a clear goal.

2) Having a clear program to achieve that goal, and

3) Knowing which training variables you will be altering within the training cycle (mesocycle) to progressively challenge the body.

4) Staying consitent for one to two mesocycles to allow true adaptations to be optimised.

Typically, rest periods remain the same through the mesocycle, and we alter other variables. Once your program is set, the only question left is, will you use your phone or your watch to time your rests?

Destiny Health