- 4-6 reps = Effective for building strength but not growth because of the lack of time the muscle is under tension (low reps). It engages all muscle fibres (in order of slow - intermediate - fast) so that the muscle can move the heavy weight. [Strength]
- 6-12 reps = Increases the time in which the muscle is under tension (which is still relatively high tension, since the weight can remain fairly high), thereby stimulating growth of the muscle size through "sarcoplasmic hypertrophy". This rep range often causes 'the pump' sensation (this is called cellular swelling, which is caused by blood flow and known to result in an increase in protein synthesis and decrease in protein breakdown). This range is most effective for increasing size, but not necessarily strength; this is why bodybuilders tend to be more muscular but not as strong as strength/power athletes. [Hypertrophy/Growth]
- 12-15 reps = This rep range is sort of caught between the middle of the the 6-12 rep benefits and the 15-20 rep benefits. It's great for beginning to increase muscular endurance, but also aids in developing some size (though not as effectively as 6-12 reps because the weight won't be as heavy). Many people will include this range as a part of "Hypertrophy", however, I tend to feel this one deserves its own definition. [Power]
- 15 - 20 reps = Increases muscular endurance and encourages cellular hydration (muscles to fill with water) by first depleting the muscles of glycogen (which, in effect, removes water as well) which then causes the body to rush glycogen back into the cells (along with water; every gram of glycogen requires 2.7 grams of water with it). This sudden increase in cellular hydration stretches the cells and leads to greater muscle growth and the release of anabolic hormones. However, it is said that this range fails to recruit fast-twitch type-2 muscle fibres [Endurance/Deload]
Why change my 10-12 rep range routine?
So as I mentioned in the opening, I wasn't WAY off the mark in focusing on 10-12 reps (like most beginners), but here's the thing: I shouldn't have stayed there so long! And this, my friends, explains why my strength and growth results eventually slowed down.
If you've been pushing out 10-12 reps (or maybe even 8-15 reps) for an extended period of time, you're likely experiencing a similar plateau. Yes, you're still burning calories and maintaining your physique, but are you making notable improvements to your size and strength? Chances are, you're not. And here's why: rep ranges are made to be altered! As I've stated before, the body is AMAZING at adapting, and in order to make notable improvements, it's important to continuously challenge the muscles in every way imaginable; this is why I strongly suggest creating a periodization workout. Once I made the switch, my strength and gains sky-rocketed!
What Are Periodization Workouts?
Periodization workouts are routines that encourage you to train utilizing a wide-range of rep ranges. Some people choose to transition from low reps + heavy weight to high reps + light weight, or visa versa; the choice is yours! The idea is, however, that you don't spend a significant amount of time utilizing one rep range; this helps to create a very well-rounded muscle (a healthy balance of strength, size and endurance).
Examples of Periodization Workouts
There are multiple different ways to design your workout, but I'm going to give you two examples:
- Periodization Week - This method means that over the course of one week, you rotate through rep-ranges. Perhaps Monday will be Strength Lower Body, Tuesday will be Strength Upper Body, Wednesday will be Hypertrophy Lower, Thursday will be Hypertrophy Upper, Friday will be Endurance Lower and Saturday will be Endurance Upper. Catch my drift? This can be effective, but also very taxing!
- Periodization Program - This is the method that I prefer, as it allows me to really master each phase. I constantly cycle through a 12-week program whereby I train for 4-weeks in the strength phase, 4-weeks in the hypertrophy phase, 2-weeks in the power phase and 2-weeks in the deload/endurance phase (once completed i start over). Since beginning this program, I have noticed a huge improvement in my strength and I've made some incredible gains!