This will explain the concept of training with different rep ranges and their impact of muscle strength, growth and endurance. It will also incorporate the idea of time under tension (TUT) and its role in training. All of this pertains to individuals who are focusing on muscle growth rather than powerlifting or Olympic lifting.
Rep ranges are typically broken down into three categories: strength, growth, and endurance. The number of reps is as follows: 1-6, 8-12, and 12-15+. For some reason the 7th rep is never included with these ranges. This is the traditional range list for people to follow to elicit the results they desire. Essentially training heavy creates strength, training with moderate resistance gains size, and training with low resistance builds muscular endurance. Now that we discussed the typical approach to training through certain rep ranges, we can begin to explain the reason behind its inadequate application to training.
Before I begin I want reiterate that counting reps is still essential to track progress and facilitate your training program, however there may be a better approach to involve in training. Time under tension is the amount of time you are placing stress on a particular muscle. Creating this tension is not difficult, but in order to maintain the tension throughout the entire range is an acquired skill. Most people will feel the contraction for the initial concentric movement and once the mid-point is passed the tension diminishes with significant loss at peak concentric contraction. Another issue is that when people lower or begin the eccentric contraction they lose all tension and simply let gravity push them down and do not fight the force to create tension. This is a major mistake when trying to stimulate growth. Eccentric contractions have been scientifically proven to promote the hypertrophic stimulus and thus are perhaps more vital to gains than lifting the weight or resistance that is being applied to the specific muscle group. Overall, neglecting of the eccentric portion of the rep creates a loss of tension and disrupts the effectiveness of the entire set being performed. Producing a constant stress or tension on the working muscle demands an intense response from the body for the muscle to maintain the movement. This facilitates blood flow to the muscle and micro-trauma, which is necessary for muscle hypertrophy. In my personal experience and from other anecdotal evidence from individuals I have encountered, time under tension is vital to maximizing gains. The ranges are as follows 5-20 seconds for strength gains, 40-70 seconds for hypertrophy, and 70-100 seconds for muscular endurance. These ranges suggest that you have certain time frames that relate directly to a specific stimulus. All of these times are in relation to muscular failure meaning you cannot complete anymore reps with good form at the end of the set. For example, you can do a set of 12 reps and say it was a failure set or your 12 rep max, which in a traditional would qualify as a growth set. In reality you probably did your first 4 reps very fast and then slowed down due to fatigue for the next 4-5 and powered through the last 3-4 with loss of form and probably neglected the eccentric portion. This is technically your 12 rep failure set, but how much tension did you create? Very little is the answer. Now using time under tension principles and proper form that keeps tension constant you take the same weight and get a better stimulus with only 6 reps. This is because you are working the muscle the entire set and not just moving weight. 12 rep traditional takes about 30-40 seconds with changes in speed every rep most likely, which keeps tension sporadic and variable. 6 reps TUT take 40-50 seconds with constant tension and an insane pump that you won't get going with traditional form. Your set would be 5s eccentric, 1s stretch at bottom, 1s hold at top that’s 7s per rep for 6 reps and totals at 42s approx. This method takes discipline, focus, and you must get rid of your ego because clearly the weight is going to be lowered or reps whatever way you wish to view it.
In the case above it shows you the ability to utilize 6 reps for muscle hypertrophy. You can also use the same concept for the high end of the range. Maintaining the same principle of constant tension you can perform sets of 15 reps at a faster pace and still stay in that range of 40-70 seconds. Again you should use these numbers as guidelines because your range may vary. You may feel that 30s is enough for you when creating maximal tension throughout a set. Just remember the idea of constant tension and focus on the time rather than the amount of up and downs you do cause that is essentially what everyone else does. You want the pump and to feel the muscle work so work the muscle when lifting and try to feel it rather than just doing 3x8 biceps curls and feeling a little warm in the arms. Personally I can do 2-3 sets of DB Biceps Curls and feel an almost full pump because I actively contract throughout the sets and have conditioned myself to activate that muscle only when performing that motion.
Ultimately, I wanted to explain that rep ranges for particular results is not as simple as most people believe. If you suck at lifting with proper form and creating tension you will struggle to utilize these ranges for any benefit. Bad form on a set of 12 is essentially a strength set for the first 6 reps and 6 reps of complete bullshit. So understand your current capacity and make it difficult for the muscle since that’s you goal. It’s not to get 12 reps it’s to work the muscle with a greater stress. That can be through more resistance or more time under tension. I can personally bench 225 (NFL Combine Weight) 15 times with momentum, loss of form and loss of tension, but with hypertrophy in mind I reduce my reps to about 8 maybe less. Again it’s a choice to decide if you enjoy this tactic and want to focus solely on muscle stress and growth. Hopefully that explains rep ranges and the misconception that will linger on in gyms everywhere. If you are doing it wrong and the muscle is not being activated you are not maximizing your time. Hence why so many people bench and have disproportioned triceps and anterior deltoids compared to chest musculature. IT’S BECAUSE THEY DO NOT WORK THEIR CHEST AND ALL TENSION IS ON ACCESSORY MUSCLES RATHER THAN PRIME MOVER!!! So simple yet so neglected the human ego makes everything difficult. Till next time...