The debate about whether high reps or low reps are better for muscle growth has been going forever. In fact, my thesis was on this exact question and I am yet to see any good evidence to favor either side.
Finally, a recent study which compared high reps and low reps sheds some light to the long- standing question.
Why are high reps (8-12 reps) better?
Bodybuilders: Bodybuilders always use low weight, high reps: 8-12 rep range .Power lifters always use high weight, low reps: 1-3 repetition range.
Growth Hormone Increase: Number of studies show that low weight, high reps (8-12 reps) with short rest increases GH significantly compared to high weight, low reps.
Based on the above evidence low weight, high reps (8-12 reps) is considered the standard recommendation for muscle growth or hypertrophy.
So why is there a debate on low weight, high reps and high weight, low reps?
Muscle Growth Studies: Surprisingly, the studies which looked at low weights, high reps and high weights, low reps show no significant difference in muscle growth.
GH ineffective: The GH hormone hypothesis of muscle growth doesn’t hold water anymore considering number of recent direct and indirect studies showing that exercise-induced increases in growth hormone (systemic hormones) do not help in muscle growth.
Greater Load: As reps decrease, the weight lifted increases. So theoretically greater the weight (low reps) , greater the potential for growth.
But what about protein synthesis & rep range?
Your muscle increase in size because of an increase in protein synthesis. So the most simple question to ask is does low weight, high reps ( 8-12) show greater protein synthesis than high weights, low reps?.
Surprisingly, nobody ever bothered to look at protein synthesis and exercise intensity until this latest study.
The study compared different intensities ( 15%, 30% 1RM, 45%1RM, 60% 1RM, 90% 1RM) to see if there is a dose response relationship to weight lifted or reps and protein synthesis. The subjects were beginners and the volume was kept similar in all groups.
What were the results of the high reps & low reps study?And guess what, there was no significant difference in protein synthesis for the 60%, 75%, & 90% 1RM! Simply put, there was no significant difference for high reps and low reps.The study showed the same results for older individuals but the levels of protein synthesis were depressed which further confirms the above results.This study finally shows why studies which looked at outcome measures couldn’t find any significant difference in muscle growth with high reps and low reps.What about trained lifters?
There no magic in the 8-12 repetition range for muscle growth. If you are using a weight above 60% 1RM, you are getting the maximum level of your protein synthesis.There is no increase in protein synthesis as the weight goes up or the reps decrease. So 5RM (low reps) is no better than a 10RM (high reps) to increase protein synthesis.Theoretically, a high rep range (low weight) would work the best for muscle growth considering there is less damage and nervous system fatigue compared to high weight, low reps but the low reps and high weight will help in building of lifting strength especially when incorporated into the compound movement. Hence we see that low reps and high reps both can give equal gain in muscle with high reps being the safer way to preserve the central nervous system and the joints whereas the low reps help in getting the strength up.
My name is Shivanjan Srivastava and i am an Engineering student in Computer Science from MIT Manipal India. I am also an ACTION certified Personal Fitness Trainer,sportsman,boxer,powerlifter and bodybuilder…I am an athlete for Protime Fitness,Division Supply Co. and startyourhealth.com and also an affiliate for rtn supplements and isupp and have been lifting for over 4 years now..above is an article i have composed and would like you all to have a look at and publish if you find it useful and worthy enough.My social media links are below