Sets and Reps

November 9, 2020

One of the most highly debated topics within the gym community is that of sets and reps and what is the ‘golden number’!

There is a basic rule of thumb that is:

For endurance – do high reps and low weight

For increased size – do moderate reps and moderate weight

For strength – do low reps and heavy weight

That being said, you have to remember everyone is different and there is no universal set and rep combination to achieve your exercise goals. I personally respond better to strength training and incorporate this into all my training plans, regardless of my goals. However, there are some people who will respond better to higher reps to achieve the same results.

To begin with it’s good to have a fundamental understanding of the science behind muscle growth. The scientific definition of muscle growth or the increase in muscle cells is muscular hypertrophy. Our muscles fibres are considered either fast- twitch or slow twitch.

Slow twitch muscles contain numerous blood vessels and they rely on a rich supply of oxygenated blood to produce energy for muscle contraction. Slow twitch muscles are highly concentrated with mitochondria and myoglobin, producing large amounts of energy slowly, supporting aerobic metabolism and fatigue resistance.

Fast twitch muscle fibres don't use oxygen to make energy, so they don't need such a rich blood supply. They are quicker to fatigue because of the lower concentration in mitochondria and myoglobin. However, their large fibres produce a greater and quicker force vital for power activities.

So let’s take a look at the 3 typical sets and reps combinations:

Strength – low reps and very heavy weight

Reps: 1 – 3

Weight: ‘As heavy as you can go’! (90-95% of your one-rep max)

This combination of sets and reps is best for promoting muscular hypertrophy. This activates your fast twitch muscles which are important for considerable strength gain but has little impact on muscle size.

It is very easy to damage your muscles with this kind of training. This should only be reserved for those with a very good understanding of technique.

Increased size – moderate reps and moderate/heavy weight

Reps: ideally 8 – 12 (can include 3-7)

Weight: 70 – 55% of your one-rep max

This is probably the most popular combination of sets and reps.

3-5 reps allow you to lift heavy with a lower risk of injury and many people have found success within this range for increased or maintained strength, power and size.

At 6-12 reps you start to tap into your muscular endurance as you increase the length of your sets with the same (albeit reduced) benefits as above.

Endurance – high reps and low weight

Reps: 15+

Weight: low (50-60% of your one rep max)

This combination isn’t enough weight to promote muscular hypertrophy like we have previously discussed. Instead, this activates and strengthens your slow twitch muscles which are endurance based and fatigue much slower. You are able to burn a lot of calories within this range which can support a ‘more toned’ appearance.  

Your magic number of sets and reps is highly dependent on your goals, the amount of time you have, your body type and genetics. You need to find your optimum balance between load and fatigue. There are many different ways to address problems such as plateaus by increasing weights OR increasing sets to achieve the same results.  

Let’s not forget about volume!

When we talk about volume, we are referring to the number of repetitions in one workout.

Ensuring you have the correct volume is paramount to your training goals and success. For example, if increasing your weight results in a drastic decrease in volume, you could end up with an ineffective training program.

Don’t be afraid to mix things up as this may be your best strategy for long-term success.