What’s the optimal rep speed?

Rep speed

When you walk into a gym, you see some people throwing the weights up while others really take their time. Does it matter which camp you fall into? If so, what’s the best rep speed?



As most of you know, the concentric part of a movement is when you’re fighting gravity (bringing the weight toward your chest when doing a curl), while the eccentric part of a movement is when you’re going with gravity (lowering the weight when doing a curl). When talking about rep speed in this article, the first number will be the concentric speed in seconds and the second number will be the eccentric speed in seconds. So (1:2) would be 1 second up and 2 seconds down. There is an obvious trade-off between rep speed and the amount of weight you can lift. In fact, one study found that going from 1 (1:1) rep speed to (10:5)  necessitated a 37% to 40% reduction in weight in order to perform the same number of reps.


The Studies:

Perhaps for this reason, super slow repetitions have been found to be sub-optimal. In one study, participants either self-selected their own speed or performed 10 second concentric and 10 second eccentric reps. The super slow group elicited less volume, force and power. Maybe a more moderate speed is the way to go then? One study found that a moderate rep speed (2:4) led to greater strength gains than a super slow rep speed. The specific results over a 10 week period were as follows: bench press (34% vs. 11%), torso arm (27% vs. 12%), leg press (33% vs. 7%), leg extension (56% vs. 24%), and leg curl (40% vs. 15%). So moderate appears to be better than slow, but what about faster speeds? Fast reps (1:1) were, in fact, shown to lead to more strength gains than moderate rep speeds (3:3) over a 6 week period. Another study compared a (1:1) to a (2:2) rep speed. Those in the (1:1) group improved more on the vertical jump and long jump than the (2:2) group. In fact, attempting to perform the concentric portion of the exercise as fast as possible has been shown to lead to the greatest strength gains.


Are there exceptions?:

One interesting study split participants into three groups. The first group lifted heavy weights for 6-10 reps at a speed of (1-2: 1-2). The second group lifted less for 20-30 reps at a speed of (1-2: 1-2). The third group lifted the same amount of weights as the second group, but performed 6-10 reps at a speed of (10:4). The results found that only the first and third group had appreciable muscle fiber growth. So, this study show that if you’re lifting light weights, slowing down the rep speed seems to be more beneficial than increasing the number of reps. The group who lifted heavy weights at fast speeds, did however, see the most gains.



Overall, the optimal speed appears to be an explosive concentric movement where you’re attempting to move the weight as fast as possible. On the eccentric movement, be sure to control the weight so that you’re not letting gravity do all the work. Some, also recommend varying your rep speed over time.



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