Training Heavy Best Way to Maximally Recruit Muscle
by: Robbie Durand
A few years ago, super-slow training was the new way to increase muscle growth. Advocates of super-slow recommended that you train with a very light weight with 1 set of 10 repetitions lasting 14 seconds each. Each repetition taking 10 seconds to lift (concentric, or positive) and 5-10 seconds to lower (eccentric, or negative).
The problem with super-slow training is that it does not work!
Researchers had subjects randomly assigned to either a super-slow group or a traditional training group. Strength was assessed for both pre- and post-test using a 1-RM on eight strength exercises. The subjects trained three times per week for ten weeks. At the end of 10 weeks, the results indicated that both groups had a significant training effect for the eight exercises, which is expected untrained subjects. When the researchers compared super-slow to traditional training, the traditional group improved significantly more than the super-slow group in total weight lifted for the leg press, leg curl, leg extension, torso arm, and the chest press. The results for the chest press indicated that the traditional group improved by an average of 26 lbs. compared to the super-slow group improving by an average of 9 lbs.
It was concluded that traditional training is superior to that of super-slow strength training for improving strength as assessed with the 1-RM for the initial phase of strength training.
The latest fad in fitness magazines is the “100-rep workout” to shock muscles into new growth. Proponents of training to failure with light weights is that maximally recruit high threshold muscle fibers without the use of heavy loads. The theory is that when muscles begin to fatigue progressively throughout a set, more motor units will be recruited to build muscle.
Researchers wanted to examine what activated muscle better, training to failure with a lighter weight, or heavy lifting. This investigation examined peak motor unit activity during sets, which differed in resistance (50, 70, or 90% 1-Repetition Maximum (1RM)). Ten resistance-trained men were assessed by electromyography (EMG) on the leg muscles (vastus lateralis and vastus medialis muscles). EMG measures the muscle activation of the muscle while contracting.
Overall, the maximal repetition sets to failure at 50% and 70% 1RM resulted in higher peak EMG amplitude than during sub-maximal repetition sets with the same resistance. However, peak EMG amplitude was significantly greater in the maximal 90% 1RM set than all other sets performed. The results of this investigation indicate that using higher external resistance is a more effective means of increasing motor unit activity than increasing the number of repetitions performed with lighter weights, even when the end point is muscular failure. Accordingly, previous recommendations for the use of heavier loads during resistance training programs to stimulate the maximal development of strength and hypertrophy are further supported.
The study did not measure muscle growth, but assuming that muscle growth is dependent on the greatest amount of muscle activation that occurs during a set, then it would seem logical that heavy lifting is going to be superior for muscle growth compared to light weight high repetition lifting. Many people are looking for the next new workout to increase muscle growth, but it may be as simple as adding more weight to the bar.
Westcott, W. L., Winett, R. A., Anderson, E. S., Wojcik, J. R., Loud, R. L. R., Cleggett, E., & Glover, S. (2001). Effects of regular and slow speed resistance training on muscle strength. Journal of Sports Medicine and Physical Fitness, 41, 154-158.
Looney, DP. et al. (2015) Electromyographical and Perceptual Responses to Different Resistance Intensities in a Squat Protocol: Does Performing Sets to Failure With Light Loads Recruit More Motor Units? Journal of Strength and Conditioning Research. In Press.
Super Slow Resistance Training – University of New Mexico. (n.d.). Retrieved from http://www.unm.edu/~lkravitz/Article%20folder/superslow.html