Effects of strength training movement speed on training results
(1-13-2013) The speed at which repetitions
you perform fitness exercises plays an important role in the effect of strength training. Depending on movement speed, different muscle fibers are targeted and adapt their contraction speed if possible. Most people interested in increasing muscle mass, often use slow movement speeds to increase muscle fatigue and time under tension. To study the effects of strength training movement speed on training results, researchers from Brazil compared training at two different movement velocities.
What have the researchers done?
The researchers recruited a total of 16 young men who had experience with strength training for this study and divided them randomly into two groups of 8 subjects. One fast contraction group and one slow contraction group. Both groups performed 4 sets of 12 repetitions of both the bench press and the incline bench press, with 50 seconds of rest between sets and two minutes between the exercises. However, one repetition in the fast contraction group took just 1,5 seconds, while one repetition in the slow contraction group took six seconds in total.
The researchers adjusted the training weights during training to ensure that each subject could perform 12 repetitions with correct form. A week before the training the scientists tested the subjects on their 1RM strength in the bench press exercise. The total amount of weight that the subjects moved during training was recorded and the subjects performed 1RM bench press tests 24, 48, 72 and 96 hours after finishing the workout.
What were the results?
The results are depicted in Figure 1 and 2 below.
Figure 1: Differences in training volume (in kg)
Figure 2: 1RM strength recovery
The fast contraction group was able to press more weight in total compared to the slow contraction group. The slow contraction group had recovered their 1RM Bench Press strength completely after 24 hours, while the Fast contraction group was significantly weaker at that time, only recovering after 48 hours. The time the muscles were under tension was 720 seconds for the slow moving group and only 144 seconds for the fast moving group.
What did the researchers conclude?
The researchers concluded that higher movement velocities allow greater training volumes and longer recovery times, as a result of more neuromuscular fatigue. Higher training volumes allow for greater gains in muscle mass. However time under tension was 576 seconds for the slow repetition group and only 144 seconds in the fast group. Although both time under tension and total training volume are imporant factors in increasing muscle mass and strength, it would seem that faster movement speeds place more stress on the muscles which should lead to greater training adapatations.
What does this mean for me?
Higher movement speeds can yield larger increases in strength and therefore muscle mass compared with slow movement speeds during training.