Slow-twitch fibers are geared more towards endurance and thrive in sustained, low-intensity activity. Fast-twitch fibers are used for explosive, high-intensity movements but fatigue quickly.
If strength and power is your aim, Veal recommends one to five repetitions per set at a higher intensity (around 85-100 per cent of one-rep max). If you’re trying to build size, up it to 8-12 repetitions per set at a moderate intensity (around 65-85 per cent of one-rep max). To stimulate those slow-twitch fibres and build resistance, aim for 13-20 repetitions per set at a lower intensity (around 50-65 per cent of one-rep max).
Vary reps depending on the workout
Not all workouts are created equal, so why are you still doing four sets of ten for every single exercise?
“In the case of workouts designed to enhance muscular endurance, like pushups or squats, I would recommend 15 reps max,” says Tomi Akande, PT at UNTIL.
Sure, you might be able to do more than 15 push-ups, but Akande says that going too far combined with inadequate recovery can lead to microtraumas in the muscles, and even hormonal imbalances that can mess up your cortisol levels, impacting muscle growth and overall health.
As a rule of thumb: focus on form and quality over quantity.
Start low to build functional strength
Following on from the last point, specialist equipment, like the TRX rig, may require an even more considered approach to reps, as Joanna Dase, a fitness coach at Curves, explains.
“If you’re new to TRX, it’s important to start with 8-12 reps per set to build foundational strength. Focus on practicing your form and achieving a full range of motion, even if it means you can’t perform as many reps.”
If you’re bored with that, upping to 12 to 15 reps will help tone your muscles, as well as enhancing your stability. For the advanced TRX practitioner, Dase recommends 15-20 reps per set, incorporating more challenging variations of the exercises while maintaining form.