The jury is out on the rep range that causes the most muscle size. Some professionals swear by the higher rep range of 15-20 reps, whilst others swear by reps as low as 3-5. The most common consensus is that a typical 8-12 rep range is ideal. However, the question remains: can a 15-20 rep range elicit great muscle growth?
Reasons why high rep ranges are great for muscle growth
1) Increasing muscle glycogen storage
High rep training is often referred to as hypertrophy-focused weight training while low rep training is often referred to as strength training. High rep training requires more glycogen, a form of energy stored in the muscles, because more energy is spent by the muscles to complete more repetitions of movement. The individual muscles will adapt by storing more glycogen in the muscle tissue. Increased glycogen storage translates to increased muscle size. This is the biggest (see the pun?) reason why high rep training increases muscle size.2) Increased joint strength
Low rep training places a heavy burden on joints, which over time can lead to injury as sufficient rest is not given specifically for joints to recover and rebuild. Joints take longer to strengthen in response to training than muscles do. High rep training strengthens joints because the muscle can be maximally taxed without overloading the joint with weights that are too heavy for them to handle. High rep training is therefore best used to build stronger joints (or recover joint strength from a previous low rep training program) before following a low rep exercise routine.
3) High reps build muscular endurance
High reps build muscular endurance, which is important for getting bigger guns.
4) Longer time under tension
Muscle grows as a response to stimulus. The amount of time a muscle is tensed on order to execute or hold a movement determines the amount of stimulus it gets, which determines the growth it will attempt to achieve. Higher reps naturally have a greater time under tension than lower reps, giving the muscle enough stimuli to prompt it to grow further.
Even though high reps can build bigger muscles, there are reasons why high rep training is not always the best muscle building rep range.
Reasons why high rep training is not the best muscle building rep range
1) High reps activate mid-twitch muscle fibers
High repetitions do not activate fast twitch muscle fibers as well as low repetitions do. This is a very important point because fast twitch muscle fibers have the ability to grow the largest, compared to mid twitch and slow twitch muscle fibers. The type of muscle fiber that is activated depends on the duration of the exercise. Low-rep weight training activates fast twitch muscle fibers, while long-distance running activates slow twitch muscle fibers, for example. This is why the leg muscles of bodybuilders are much larger than those of marathon runners. Therefore, in order to achieve the best possible muscle size, a lower rep range (lower than 15-20 reps) is ideal as they will better target the potentially bigger, fast twitch muscle fibers.
2) High reps require more calories
High rep training uses up glycogen stores, which the body gets from carbohydrates. More calories are needed to sustain a high rep training routine, meaning that less of these calories are actually used for building muscle. This is easily avoided, though, by consuming more calories through the diet.
3) High rep training places stress on the Central Nervous System
Since muscles are placed under tension for longer periods of time, the central nervous system is also placed under stress for a longer period of time, especially if worked until failure after every set. This point is not as important as the first 2 points because ALL exercise places stress on the central nervous system, including low-rep training. The central nervous system will adapt to exercise by getting stronger and more able to cope with the stress, but this takes time and too much stress placed on the central nervous system can lead to over training.
If high rep training is great for muscle growth but not the best rep range, then what is the best rep range?
The best rep range is the one you haven't done. This is because the best thing to do is vary between rep ranges for the best muscle growth over time.
Why should you vary your rep ranges?
1) Muscle confusion
The number 1 reason why you should vary your rep ranges is because of muscle confusion. The muscle grows by being forced adapt to a stimulus. Muscle growth will plateau over time as it gets accustomed to a certain stimulus and therefore does not feel the urgent need to grow and adapt anymore. This is why people who change from a low rep range to a higher rep range (and vice versa) experience greater muscle growth. It is advised to change your workout program every 3rd month or so for the best results, altering things like your rep range, number of sets, exercise order, rest in between sets, style of training, etc. or a combination of the above.
2) Joint strength
Lower reps activate fast twitch muscle fibers the best, but can take their toll on joints over time. Higher reps strengthen joints the best but don't activate the fast twitch muscle fibers as well as lower repetitions. By alternating between rep ranges, muscle can optimally strengthened as well as joints. To read more on joint pains from exercise and recovery, click here.
3) Muscle strength and size
By alternating between different rep ranges, you can focus on building muscle strength as well as size. Some rep ranges will increase the one more than the other, even though both will increase with both rep ranges. Strength and size are very closely interlinked (strength is needed to lift heavier to grow and size is needed to house more strength), but different exercises and rep ranges affect the balance of this spectrum differently.
Which rep range is best suited for beginners?
The higher rep range is best suited for beginners for the following reasons:
1) Form
Beginners need to focus on using the right form (executing the exercise the right way) more than anything else to stimulate muscle growth and avoid injury. After a while, lifters start to get a feel for what form is correct and what form is not. By using higher repetitions and therefore lower weights, more emphasis can be placed on learning, practicing and getting the feel for the right form.
2) Joint Strength
As discussed above, high reps will be needed to strengthen joints so that heavier weights can be lifted later on.
3) Mind-to-muscle connection
Beginners need to develop a mind to muscle connection, which is the ability to force a muscle to perform at its maximal output for an extended period of time. Low rep ranges rely heavily on an already developed mind to muscle connection in order to get the most out of every rep. High reps are a great way to develop this connection.
4) Muscular Endurance
Higher reps develop muscular endurance, which is greatly needed to push the muscle to a point where it is optimally stimulated to grow. High reps develop this faster than lower reps do.
We hope that you have learned something from this article. High reps can indeed increase muscle mass, but the best way to do so is through a varied rep range. STAY STRONG!
