Repetition Speed and Muscle Growth

 

Does your speed of movement during each repetition of a strength training exercise matter?

A new meta-analysis, published in the Journal of Strength and Conditioning Research, looked at repetition speed aka rep tempo to determine the effects that it has on muscle growth (hypertrophy).  It reviewed 14 separate studies and considered how tempo – both during the lifting and lowering phases – affected muscle growth.

Study Results

The study showed that using slower and faster rep tempos made very little difference on muscle growth.  'In conclusion, resistance training tempo appears to have minimal overall effect on muscle hypertrophy, with potential differences emerging under specific conditions,' researchers stated.

During the lifting portion all studies reviewed showed slightly better results with a quicker, more explosive tempo.

During the lowering/eccentric phase differences in rep tempo proved essentially negligible for hypertrophy. Therefore slowing down the lowering phase does not actually provide more benefits than moving the weight more quickly.

What Does This Mean?

While it proves that focusing solely on tempo is not productive, it does not mean you should disregard the eccentric or lowering phase of lifts. For example, dropping down fast during a heavy squat is a sure-fire way to pick up an injury, so there still needs to be an element of control whenever you're lowering the weight. Plus, it is well established that concentric only training does not stimulate muscle growth as much as concentric-eccentric training.

In addition, there is a place for slower tempo movements to allow you to focus on controlling the movement.   In addition, a slower tempo helps avoid using momentum or throwing the weight.    Throwing the weight paradoxically deloads the muscle in one place and overloads it too much in another.