Rep ranges are all the fuss in the fitness community. Everyone has different training goals. Some train for strength, some train for endurance and some train for hypertrophy. Rep ranges will vary according to what you are training for and thus why you are hearing different opinions on it.
Let’s talk basics
Our muscles respond to “new” or “novel” adaptations. If you are a beginner and an untrained individual, any load will act as a shock and a novel stimulus on your muscles. In other words, our muscles respond to a new stimulus, so if you have never stepped a foot in the gym, any rep range or load will shock your muscles and will lead to an adaptation and muscle growth. If you have been training for a while; however, this is when it gets tricky. If you are training for hypertrophy, then you are most probably sticking to higher rep ranges 8-12 or 20+. Higher rep ranges will ask for a lighter load than if you were to train for fewer reps. The higher the rep range the lighter the load would be (you can not squat 200 Kgs for 35 reps). Eventually, muscle adaptation will occur and the rep range will stop providing stimulus. Higher reps require you to focus for a longer time than if you were to train for fewer reps. Think about it, it is hard to stay focused and have proper form with a high load for 35 reps. For the majority of people training for hypertrophy, a rep range of 8-12 works best. BUT again remember! Your muscles react best to a novel stimuli. Here is when lower rep ranges come into play.
Lower rep ranges are known for their efficiency for strength (think powerlifters). The rep range you are sticking to somewhat dictates your load. In order to “shock” your muscles, a different (higher load) is the best route. This will only be possible with a lower rep range. A repetition range of 6-12 can certainly be heavy enough to stimulate strength improvement BUT for best efficiency heavier loading in the 1-5 rep range is necessary. Lower rep ranges allow you to load a lot heavier than higher rep ranges. This allows you to easily provide a new stimulus for your muscles and will lead to increased strength.
Regardless of what you are training for, you must be seeking to provide your body with new stimuli. With the right conditions, both high and low rep ranges will lead to hypertrophy. for maximal strength adaptations, you must incorporate heavy loading with fewer repetitions. Whether you are seeking hypertrophy, strength or endurance; find out the best rep range that works for you but remember to mix low, intermediate and high reps in your training.