Recent studies have shown some controversial findings that high-rep training appears to be as effective as the traditional medium rep training for muscle growth. If you missed it, you can find out more in my two previous articles:
In this article I will show some examples of how high-rep sets can be implemented in a serious weight lifting program, and look at the results of some studies that have investigated this.
Periodized weight training and training variety - a necessary strategy for continued progress
I will save an in-depth discussion on periodized weight training for a separate article. The take home from studies on periodized weight training is that training periodization, or variation, is key for breaking through training plateaus and for making continued progress in both strength, power and muscle growth 1. Benefits with periodized weight training have been seen in both beginners 1-4 and experienced athletes 1, 2, 5-9, but it is especially critical for advanced weight lifters, bodybuilders and other athletes.
Training periodization can be accomplished in many ways; the training variables that are most commonly manipulated are intensity (weight lifted and number of repetitions), number of sets, rest between sets, and lifting speed. In this article I will cover training intensity and lifting speed, since these training variables are directly related; the slower you lift the lighter the weights you can move, and vice versa.
High-rep finishing sets after heavy, high intensity workouts in a periodized training program - how does it affect gains in muscle mass and strength?
An interesting study investigated muscular adaptations to a combination of high- and low-intensity resistance exercise in a periodized training program 4.
The following 3 different types of workouts were tested:
- Hypertrophy (classic muscle building)
9 sets of medium intensity (10 repetition maximum [RM]) short inter-set rest period (30 s) with progressively decreasing load.
5 sets of a high-intensity (90% of 1RM) and low-repetition exercise.
1 set of low-intensity and high-repetition exercise added immediately after the last (5th) set in the strength-type regimen.
The hypertrophy type phase consisted of nine sets at 80–40% of 1RM. The each workout was divided into three parts with three sets each, and the rest periods between sets and parts were 30 seconds and 3 minutes, respectively. In each part, the intensity was gradually lowered set-by-set (multi-poundage or descending set system).
The diagrams below outline the training periodization, and the workout protocol in each phase.
The subjects were young men (20-23 years) with a couple of months of recreational resistance training experience, but they had not taken part in any regular training program for at least 6 months prior to the study.
Before the start of the 10 week training program, acute changes in blood levels of growth hormone (GH) were measured after one bout single of each workout type, using leg extension. As illustrated in figure 2, there were significant differences in post-exercise increases in GH levels: hypertrophy-type > combi-type > strength-type.
Next, the long-term effects of a periodized training protocol with these different types of workouts was conducted. The subjects were assigned to either a hypertrophy/combi (HC) or hypertrophy/strength (HS) group and performed leg press and extension exercises twice a week for 10 weeks.
During the first 6 weeks, both groups used the hypertrophy-type training to gain muscular size.
During the subsequent 4 weeks, the HC group performed combi-type training, and the HS group performed strength-type training.
Muscular strength, endurance, and cross sectional area (muscle size) were examined.
After the initial 6 weeks, no significant between group differences was seen in the percentage changes in any of these outcomes.
However, after the subsequent 4 weeks, 1RM of leg press and muscular endurance of leg extension showed significantly larger increases in the HC group than in the HS group. In addition, increases in muscle growth (cross sectional area) after this period also tended to be larger in the HC group than in the HS group. It was also found that adding low-intensity high-repetition set didn't interfere with neuromuscular adaptations 4.
Lifting speed and time under tension (TUT) - another variable to consider in high-rep sets
High-rep sets differ from low-rep sets in that they allow more control of lifting (repetition) speed, due to the lower weight lifted. And lifting speed deserves way more attention than it has been getting...
Lifting speed is important because it determines time under muscle tension, which is the amount of time muscles must contract to complete a set. According to one of the most successful strength training coaches in the world, Charles Poliquin, in order to develop maximum muscle mass, every set should provide muscle tension (contraction) for 20-70 seconds 10.
Am interesting recent study compared the effects of difference lifting speeds on synthesis of different muscle protein fractions 11. The subjects (recreationally resistance-trained young men) did an exercise bout consisting of 3 sets of unilateral leg extension (one leg lifting slowly, the other fast), at 30% 1RM, with 2 min rest between sets:
Slow lifting speed: 6 seconds up and 6 seconds down, no pauses until failure
Fast lifting speed: 1 second up and 1 second down, no pauses
The fast lifting speed condition was matched to the slow condition for contraction volume (meaning that the leg performed an identical number of reps at the same load), but not to failure.
Participants ingested 20 g whey protein immediately after the exercise bout. The number of repetitions performed was 12, 7 and 6 for set 1, 2 and 3. As planned, the muscle time under tension (measured in seconds) was greater for each set in the slow condition compared to the fast:
Slow lifting speed time under tension: set 1 - 144 s (12x12); set 2 -84 s (12x7) and set 3 - 72 s (12x6)
Fast lifting speed time under tension: set 1 - 24 s (2x12); set 2 -14 s (2x7) and set 3 - 12 s (2x6)
The interesting finding in this study was that myofibrillar protein synthetic rate was about 30% higher in after the slow lifting speed bout versus the fast lifting speed bout after 24-30 h recovery, and correlated to p70S6K phosphorylation (which is a marker for anabolism and hypertrophy 12). The slow lifting speed bout also significantly increased both sarcoplasmic and mitochondrial protein synthesis rate 6 hours post-exercise, compared to the fast lifting speed bout.
A slightly faster lifting speed than used in this study, 3 s up and 3 s down (this is still slower than the usual 1 s up - 1 s down), with a slightly heavier load (around 40-50% of max strength) would be more anabolic towards the myofibrillar fraction (which is the muscle protein fraction that is responsible for muscle growth) 13. This agrees nicely with Poliquin's suggestion that muscles should contract 20-70 seconds during a set to develop maximum muscle mass.
Another study compared a slow lifting speed of 3 seconds up and 3 seconds down at an intensity of 40% 1RM to failure, with a fast lifting speed of 1 second up and 1 second down at an intensity of 80% 1RM to failure, in 5 sets of leg extension 14. The subjects were heavy-resistance exercise trained young men. A striking finding in this study was that the slow lifting speed bout resulted in almost a 3 fold higher elevation in free testosterone than the fast lifting speed bout 14.
It has also been shown that low-intensity exercises with different slow lifting speeds on the up (concentric) and down (eccentric) phases of contractions (3 s up - 3 s down, 5 s up - 1 s down, 1 s up - 5 s down) all significantly result in greater GH elevation compared to fast lifting speeds (1 s up - 1 s down), regardless of the time to complete up and down actions 15.
Finally, there are indications that going faster on the lowering (eccentric) part of contractions than the lifting (concentric) part, leads to greater hypertrophy and strength gains than slow lengthening contractions 16.
Oki, let try to make sense out of all this...
The above mentioned studies, in conjunction with the findings that high-rep training is as effective as the traditional medium rep training for muscle growth (as outlined in part 1 and 2), underscore the effectiveness of incorporating lighter higher rep sets with slower lifting speeds into your workouts for muscle growth.
In a periodized training program, adding some light high reppers to the end of heavy lifting sets actually increases strength more than just doing the heavy lifting sets alone. However, this might only apply to novice trainers. However, in recreationally resistance-trained men, light high reppers, especially when performed with a slow lifting speed, have been shown to stimulate muscle growth. It is not necessary to follow that classic linear periodization model where one trains in a specific way for several weeks. Actually, making program alterations on a daily basis is more effective in eliciting strength gains than doing so every 4 weeks 17. The increase in exercise induced elevations of GH seen with lighter high rep sets done with a slow lifting speed is especially interesting for you if your goal is to lose fat, since GH plays a key role in metabolism and boosts fat burning and energy expenditure18-22.
To add variety to your typical workouts, doing lighter high rep sets with a slow lifting speed, especially on the up (concentric) part of the contractions, not only markedly increases exercise induced elevations GH and free testosterone, but also leads to greater hypertrophy and strength gains. This can be explained by a greater muscle time under tension, which increases muscle protein synthesis. For maximum muscle mass development, aim for sets that keep your muscles contracted at least contract 20-70 seconds.
Ok, here's the final exam question:
- What's the difference between an exercise novice old fragile lady who does 30 rep sets, and a muscular bodybuilder who does 30 rep sets?
the old lady does light high rep sets in order to practice correct exercise form, develop basic conditioning, and avoid injuries. The muscular bodybuilder does light high rep sets in order to add variety to his relatively intense training program and thereby get muscle stimulus from a new type exercise stress, which is necessary for continued training progress.
Even though both the old lady and the muscular bodybuilder might periodically be working out at the same relative intensity (that is, the same percentage of their respective 1RM), the bodybuilder will of course be moving much heavier weight than the old lady because his maximal strength is so much higher. Hey guys, remember that when your egos start acting up!
When looking at bodybuilders and other athletes it's important to keep in mind that the type of training they did in the past to get where they are in the present isn't necessarily the best for taking their physiques and performance to the next level. Training variety is essential for continued physical (and mental!) development.
Bottom line, lighter high rep sets with slow lifting speeds, when taken to failure, are not a waste of time in the gym, like many bodybuilders and strength athletes think. To the contrary, lighter high rep sets with slow lifting speeds add two new training variables to your workout, which can help you to break through training plateaus and boredom that arise from constantly doing the same thing in the gym. Thereby, high reppers and sets with slower lifting speeds will help ensure continuous training progress and propel you towards your weight lifting goals.
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- Monteiro AG, Aoki MS, Evangelista AL, et al. Nonlinear periodization maximizes strength gains in split resistance training routines. Journal of strength and conditioning research / National Strength & Conditioning Association. 2009;23(4):1321-1326.
- Poliquin C. The Poliquin Principles: Successful Methods for Strength and Mass Development 1997.
- Burd NA, Andrews RJ, West DW, et al. Muscle time under tension during resistance exercise stimulates differential muscle protein sub-fractional synthetic responses in men. The Journal of physiology. 2012;590(Pt 2):351-362.
- West DW, Burd NA, Staples AW, et al. Human exercise-mediated skeletal muscle hypertrophy is an intrinsic process. The international journal of biochemistry & cell biology. 2010;42(9):1371-1375.
- Burnd N. Muscle time under tension - personal communication. 2012.
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- Shepstone TN, Tang JE, Dallaire S, et al. Short-term high- vs. low-velocity isokinetic lengthening training results in greater hypertrophy of the elbow flexors in young men. J Appl Physiol. 2005;98(5):1768-1776.
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