There are generally two schools of thought as to how fast you should lift weights:

  1. You should lift weights slowly.
  2. You should lift weights quickly.

Who’s right? 

Well, not many studies have tried to answer this question, which is why we jumped at the chance to help support emerging research on the topic.

Specifically, last year we donated several bottles of our best-selling 100% natural pre-workout supplement, Pulse, to a team of scientists based at the University of Tampa who were conducting a study on the ideal weightlifting tempo for muscle gain (including Chris Barakat, a member of Legion’s Scientific Review Board). 

So far, studies have gone back and forth on whether you should use a slow or fast weightlifting tempo, with most showing small differences in tempo don’t seem to matter much one way or another. For example, several meta-analyses have found that a slow weightlifting tempo (> 2 seconds) was equally effective for gaining strength and muscle as a fast weightlifting tempo (<1 second). 

In these studies, though, weightlifting tempo was usually measured as the total length of time it took to complete a single rep. That is, if the concentric (raising) portion of the rep took 1 second, the eccentric (lowering) portion of the rep took 2 seconds, and there was a 1-second pause in between, the entire rep would have a tempo of 4 seconds.

Some research had found that the eccentric portion of a rep seems to be responsible for much of the muscle-building benefits, which led the authors of this study to hypothesize that increasing the eccentric portion of the rep (and not just the length of the entire rep) might boost muscle gain. 

In this study, the researchers had 18 men aged 18 to 35 train one leg with a fast weightlifting tempo, and the other leg with a slow weightlifting tempo. 

Here’s how Chris Barakat explains the rationale for this study design: “. . . we utilized a ‘within-subject’ design to minimize confounding variables (e.g. dietary protein/calorie intake, sleep, genetics, etc.) between individuals . . . if you did SLOW tempo on both legs, and I used FAST tempo on my legs, and you outgrew me, it may have been due to the tempo, but also could be due to your genetics, nutrition, sleep, etc.”

Specifically, the fast weightlifting tempo involved doing leg extensions with a tempo of 1-0-1-0 (1-second concentric, no pause, 1-second eccentric, no pause). The slow weightlifting tempo involved doing leg extensions with a tempo of 1-0-3-0 (identical to the first group except with a 3-second eccentric). 

The researchers also randomized which tempo the participants used with which leg. That is, some people trained their right legs with a fast tempo and their left legs with a slow tempo and vice versa. 

All of the men had at least three years of weightlifting experience, and could barbell back squat at least 1.5 times their body weight (pretty stronk!). 

They trained twice per week for eight weeks, and the researchers measured their thigh muscle thickness and leg extension one-rep max before and after the study. Before each workout, the subjects also drank a serving of Legion Pulse to ensure they were fully prepared for their training. 

After collecting and analyzing all of the data, the researchers found that both groups gained about the same amount of strength and muscle overall, but that the fast weightlifting tempo group gained slightly more muscle in the lower portion of their thighs.

This flies in the face of the commonly held belief that slower weightlifting tempos, especially slower eccentric weightlifting, is better for muscle growth, and adds to the body of evidence showing that you’ll likely make equal or faster progress by lifting weights with a fast tempo (while maintaining good form).

Congrats to the team for conducting this study so we can make the most out of our time in the gym!

If this piqued your interest, check out the other research we’ve funded on nutrition, exercise, and supplementation to help advance our collective understanding of how to live fitter, healthier lives.