Repetition speed – how fast you lift a weight and how fast you lower a weight – has always been somewhat of a controversy among lifters.
Some say that the eccentric, or lowering phase, is everything when it comes to hypertrophy and the concentric, or lifting phase, is everything when it comes to strength. And there are plenty of really annoying guys who don't know the difference between the two phases, don't give a shit, and still grow.
But all you have to do is use a bit of Sherlock Holmesian deduction the next time you go in the gym. You'll likely observe that many of the guys who lift purely for speed, strength, and explosivity don't look as muscular as many of the bodybuilders, who, at least some of the time, play around with their lifting speeds.
It's undeniable – despite the success of the annoying guys who grow regardless of what they do – that lifting speed alters important factors affecting hypertrophy and strength development; things like time under tension, muscle activation, and metabolic and hormonal responses.
How much does speed alter strength and hypertrophy? Scientists in Sao Paulo, Brazil, say "slow speed" reps can help you build muscle up to 3 times faster than "fast speed" lifting. However, in a surprising twist of accepted lifting principles, they also found that slow speed lifts can progress strength up to five times faster than fast-speed reps.
The scientists rounded up 12 experienced male lifters and got them to do Scott curls twice a week for 12 weeks. Half of the men performed "slow speed" reps where they lifted the weight in one second, but lowered it over the course of three seconds.
The other half did "fast speed" reps where they took a second to lift the weight and a second to lower the weight.
The workouts consisted of the standard 3 sets of 8 reps (of which the 8th rep constituted failure). As far as testing methods, they employed ultrasound examination of cross-sectional area of the brachialis biceps muscle, along with before and after 1-rep curl maxes of each of the test subjects.
After 12 weeks, the men in the slow speed group showed nearly five times the progression of strength than that shown by the fast speed lifters. The slow speed lifters also built three times as much muscle as the fast speed lifters.
The results, while hugely impressive, don't necessarily mean you should automatically turn into Eddy Eccentric and measure your sets in geological time. Instead, the lesson should be that it's a great idea to periodically employ slow tempo lifting into your workouts for periods perhaps as long as 12 weeks, after which you can go back to faster tempos for a while.
- Pereira PE et al. Resistance training with slow speed of movement is better for hypertrophy and muscle strength gains than fast speed of movement. International Journal of Applied Exercise Physiology. 2016 Jul;5(2):37-43.