Bodybuilders and fitness fanatics can build up three times as much muscle mass and five times more strength if they take three seconds to do their return movements instead of just one second when doing reps. Brazilian sports scientists at the Universidade Federal de Sao Paulo write about this in the International Journal of Applied Exercise Physiology. Study The researchers got 12 healthy men, all experienced strength trainers, to train their biceps by doing Scott curls twice a week for 12 weeks. Each workout consisted of three sets of 8 reps. The men trained to failure. Half of the men made relatively fast movements. They took one second each to do the lifting and lowering movements [Fast Speed]. The other half did their reps more slowly. They took one second for the upward movement, but three seconds to do the lowering movement [Slow Speed]. The researchers made scans so they could measure the circumference of the participants' biceps, before and after the twelve weeks. In addition they measured the amount of weight with which the men were just able to complete one rep of the curl [1RM]. Results At the end of the 12 weeks, the participants in the slow speed group had made almost five times more progression than the participants in the other group. In terms of muscle mass, the slow-speed group had done three times better than the high-speed group. Conclusion "We conclude that slow speed training is more effective to improve hypertrophy in well-trained adults", the Brazilians wrote.
I always found it was harder going slower. Now I know it's also better! I've seen so many folks at the gym rushing through their reps. I guess they figure "a rep is a rep".
Can't comment on the numbers, but the general idea makes sense. A lot of people pay little or no attention to the negative/eccentric half of an exercise movement, which sells the set short. But I think the one-second positive/concentric movement in the study is also somewhat too fast. I'm not a fan of SuperSlow by any stretch, but I think there is more benefit to be had with a more deliberate movement. One second suggests speed and momentum, which reduces intensity.
Baron, is this a new study? Have a link to the scientific data? Time under tension is a real thing. Many studies have been done over the years. From what I can remember, the optimal time for a 8-12 rep set is 40-60 secs. I like to follow a 1-1-3 tempo on all my body weight and isolation exercises. 1 sec push/pull as explosive as possible, 1 sec pause/squeeze and a 3 sec negative. It's made a big difference for me.
Well, the movement has to still be controlled and not jerky so it's more of a mindset than actual speed. Point is to not think about slowing down the movement and if the weight is heavy enough nothing will be exploding anyway.
Okay. I was just a bit concerned about a rep being characterized as explosive. By definition, an explosive rep employs momentum and therefore has more force at the beginning of the concentric phase and substantially less at the end of the concentric. I would think that a uniform distribution of force throughout the rep would maximize intensity, thereby optimizing results.* So I agree with you about the movement being controlled rather than jerky. Even so, a one-second concentric phase seems rather short for anything other than calf raises. __________________________ * One researcher suggested that explosive lifts would likely recruit fewer muscle fibres due to momentum and that the diminished recruitment through most of the range of motion would be less effective for enhancing muscle function. (Johnston BD. Moving too rapidly in strength training will unload muscles and limit full range strength development adaptation: a case study. J Exerc Physiol 2005; 8: 36-45.) Another study suggests that "persons should maintain steady force production throughout a range of motion and reduce external forces such as momentum; movements should be of a pace that maintains muscular tension, not explosive or ballistic in nature. Faster movements cause greater peaks in both muscular and ground reaction forces which likely transfer through joints and connective tissue, potentially causing injury." http://ssudl.solent.ac.uk/3127/1/Evidence Based Resistance Training Recommendations.pdf
Yes, I've read that as well. However, there are those who disagree. "...There is very little evidence to suggest that a specific range of repetitions (e.g., 3-5 versus 8-10) or time-under-load (e.g., 30s versus 90s) significantly impacts the increase in muscular strength, hypertrophy, power, or endurance." I'm inclined to agree with this conclusion. As long as the reps are being done in good and deliberate form to failure for a reasonable rep range, I would imagine that is all that is required to provide the necessary overload for improvement.