In fitness, there are some myths that just seem to stick. Even when evidence to the contrary emerges, there’s always a delay between the truth emerging and people changing their training habits. One of the tried and tested ‘truths’ we’re going to explore to day is the need to train heavy in order to gain muscle.
Is it true, or is it time we updated our thinking on the matter?
For decades the thinking has been that in order to grow muscle, you really should be lifting medium-heavy weights in an 8-12 rep range. Whilst there’s plenty of research supporting this approach, one question we can ask is ‘is it the only way, or can you build muscle with high repetition weight training?’
That’s what we’re about to explore in this blog post…
Muscle is a varied tissue…
A quick physiology lesson…
Not all muscle tissue is the same. In a given muscle, there’s a mixture of different fibre types, each with their own unique properties. Without going into serious detail, you can largely divide these into type 1 muscle fibres, and type 2 muscle fibres.
Type 1 fibres are commonly known as ‘slow twitch’ fibres. They take longer to fatigue, but their capacity to generate force and increase in size is limited. People who have great endurance are usually type 1 dominant in the sense that type 1 fibres make up more of their muscle mass. They’re less likely to be big, strong and powerful, but they’d run a 10k race without trying!
Type 2 fibres are spilt into several different types (but that’s not especially important here). They’re known as ‘fast twitch’ fibres. These are the opposite of slow twitch fibres. They have a greater capacity for growth, force generation and strength, but they fatigue quickly. Fast twitch dominant people excel in strength and power events, but would find a 10k race a challenge.
Training the different muscle fibre types…
Just as they have different capacities, the different fibre types respond well to different types of training. Given most of us aren’t at the extremes of fibre type distribution (like we see in the above examples), we would respond better to a varied type of training.
Bolt may be 80% fast twitch fibre, Kipchoge the same for slow twitch fibres. The rest of us will be much closer to 50% each (with some variation of course).
If we solely focus on one type of training, we leave behind the other fibres. That’s exactly what we’re doing though if we train within the same rep range all of the time. We don’t give much opportunity for the fibres we’re neglecting to maximise their capacity for growth. Imagine the possibility for improvement if we make the other 50% of our muscle work as it should!
What does the research show about high rep training and muscle growth?
There has been a few research studies around the effectiveness of lighter weight, higher repetition weight training for muscle growth (hypertrophy). The results have been clear - it works!
One of the pre eminent researchers in the space is Brad Schoenfeld and his research team identified in a 2015 study that lower weight, higher rep training approach helped to increase muscle growth. It also had the secondary benefit of improving muscle endurance. Whilst the research clearly stated that in order to maximise strength you have to lift heavy, when it comes to muscle growth, there’s certainly a place for higher rep work.
This isn’t the only study to conclude these results either…
A 2017 meta analysis of the data around low load training for hypertrophy concluded that muscle hypertrophy can be equally achieved across a spectrum of loading ranges.
Finally (because we’re at risk of labouring the point too much), research as recently as 2021 has analysed significant amounts of data and previous studies and has concluded yet again that… the compelling body of literature indicates that similar whole muscle growth (i.e., muscle thickness, CSA) can be achieved across a wide spectrum of loading ranges ≥ ~30% 1RM. These findings are independent of age and training status.
The point being, the science is showing us that yes, you can build muscle with lighter weights and previous assumptions that you couldn’t, are wrong.
Tips to maximise muscle growth with lighter weights
A few tips to getting the most from your lighter weight hypertrophy training…
Stick with full body workouts - stimulate more muscle with each session. Forget split routines here and go the whole hog! Whole body every time.
Train to failure - if you’re going to build muscle with lighter weights, you’ve got to go to failure. No half measures. This is especially important when it comes to isolation exercises.
Use compound movements - these are the big, multi-joint movements. Think squats, bench press, deadlifts, rows, overhead presses etc.
Train frequently - lighter weights will mean less recovery. Shoot for 4-6 workouts per week, making sure you follow all of the advice above.
Using lighter weights to build muscle in an excellent way to shake up your training. It also helps to give your body a break, it aids with connective tissue strength and health and gives you a new challenge to focus on!
It could be just the change your training needed…
The AdMac Fitness personal training studio is in Bow, E3. We have personal trainers with a range of specialities, so we can offer the ideal personal trainer to help you achieve your goals. For more information on who we are, what we do and how we can help you achieve your health and fitness goals, contact us on… 07921465108 or email us at admacfitness@gmail.com. We look forward to hearing from you!