The Benefits of Mixing in High Rep Days for Muscle Growth

When it comes to building muscle, most gym-goers immediately think of heavy weights and low reps. And while that classic formula works well, it’s not the only route to gains. Adding high-rep training days into your routine can offer some serious benefits, both for muscle growth and overall progress.

If you’ve been lifting heavy for a while, here’s why it might be time to mix things up with some high-rep sessions…

High Reps Build Muscle

Yes, really. While lifting heavier weights with lower reps targets strength and fast-twitch muscle fibres, higher-rep sets (think 15–20 reps or more) also stimulate muscle growth, particularly when taken close to failure. This type of training increases time under tension, metabolic stress, and muscular fatigue, all of which are key drivers of hypertrophy (muscle size gains).

Research from 2015 titled Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men concluded… ‘These findings indicate that both HL and LL training to failure can elicit significant increases in muscle hypertrophy among well-trained young men’.

So, don’t assume high reps are just for toning — they’re a legitimate way to grow.

There’s Less Connective Tissue Damage

Heavy lifting can take a toll on your joints, tendons, and ligaments, especially if you’re training hard and often. Mixing in high-rep days allows you to give your connective tissue a break while still training with intent. The lighter loads used in high-rep work are generally easier on the body while still delivering a powerful training effect for your muscles.

It’s a smart way to reduce injury risk and keep your body feeling good for the long haul.

They’re a New Challenge to Mix Up Your Workouts

Stuck in a rut with your training? Changing rep ranges is a great way to keep things fresh. High-rep sets challenge your muscles (and your mind!) in a different way. You’ll feel the burn, work your endurance, and probably find a few weaknesses you didn’t know you had.

This variety can reignite motivation and help break through plateaus, giving your muscles a new reason to grow.

High Reps Challenge Slow-Twitch Muscle Fibres

Most traditional weight training targets fast-twitch muscle fibres — the ones responsible for strength and explosive power. But your body also has slow-twitch fibres, which are more endurance-focused. High-rep training targets these fibres, promoting more balanced development across your muscle groups.

By training both types of fibres, you’re building a more complete, functional physique — and potentially increasing your muscle endurance too.

High Rep Days for Muscle Growth

Adding high-rep days to your routine isn’t about replacing heavy lifting — it’s about complementing it. By combining different rep ranges across your training week, you’ll challenge your body in new ways, reduce wear and tear, and tap into all the mechanisms of muscle growth.

So, next time you’re planning your workouts at AdMac Fitness, consider going lighter with higher reps. Your muscles (and your joints) will thank you.

Want to improve your health and fitness? Let the AdMac Fitness Personal Trainers help…

AdMac Fitness has been helping the people of East London transform their health and fitness for nearly a decade.

We help people using tried and tested fitness approaches. Our expert team of personal trainers, based in both Bow and South Woodford can help you get a grip of your health forever. With our guidance and experience, you can relax knowing that your fitness journey is going to be guided by some of the best personal trainers in East London.

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!

Our locations are…

AdMac Fitness: Arch 457 Robeson St, London E3 4JA

AdMac Fitness South Woodford: Unit 4 Marlborough Business Centre, 96 George Lane, South Woodford, London, E18 1AD