To summarize the results, to increase the weight weekly and increasing reps are equally effective for muscle growth, but the increased reps group had a favorable increase in muscle growth of the rectus femoris compared to the increased weight group. Increasing the weight was marginally more effective for increasing 1-RM maximal strength, and both groups equally increased muscular endurance. If you want to gain muscle, you can take periodic breaks from heavy lifting and just focus on adding more reps, and muscle growth will be similar.
STUDY EXAMINES HIGH VOLUME VS HIGH INTENSITY EXERCISE AFFECTS ON MUSCLE GROWTH
HIGH VOLUME VS INTENSITY WORKOUT: RESEARCH FINDS ONE IS BETTER THAN THE OTHER SUMMARY
- Both groups increasing weight and high volume (i.e., increasing reps) had similar increases in muscle growth, but the increased repetitions group had a small advantage in resulting in better muscle growth.
- Greater increases in 1-RM strength leaned in favor of the heavyweight group compared to the increased reps group.
To effectively build muscle, many fitness experts commonly advise adhering to a progressive resistance exercise protocol. Intricately designed, this protocol emphasizes the importance of gradually increasing the weight and/or repetitions throughout a training cycle. By adopting this approach, progressive resistance exercise ensures that the muscle consistently experiences a gradual escalation in tension. This methodical increase in tension is pivotal as it provides a continuous and progressive stimulus for muscle growth. Traditional resistance exercise models either progress the weight while reducing reps based on a percentage of one-repetition maximum (1RM). (2)
Research has previously found that muscle growth/hypertrophy can take place in a wide spectrum of reps (i.e., 5-30 reps) and weight ranges (i.e., 30% -90% of a 1-RM) as long as the total workload is similar. (3) It is currently unknown whether an increase in reps or an increase in weight is the optimal choice to increase muscle growth. Some favor high-volume training, whereas others favor high intensity, but no one has ever examined a head-to-head competition. Check out the Reddit high volume vs high intensity thread. Most would suggest that, based on the research, a high-volume workout would favor muscle growth.
IS HIGH VOLUME REALLY SUPERIOR?
A recent study compared the effects of load increases while keeping repetition range constant vs. increasing repetitions while keeping the load constant on measures of lower body muscle hypertrophy, strength, jump performance, and local endurance in resistance-trained individuals over an 8-week study period. The researchers hypothesized that both groups would have similar increases in muscle growth, but the group that increased weight every week would have better increases in strength, whereas the group that increased reps would have greater increases in muscular endurance.
The resistance training protocol comprised lower body exercises and consisted of four sets of free-weight back squat, leg extension, straight-leg calf raises, and seated calf raise.
Participants were prescribed the same upper body RT program with a traditional progression model to follow on alternate training days (without supervision from the researchers). They were instructed not to perform any additional lower body RT for the duration of the study. One group increased the weight they used every week, whereas the other group kept the weight the same but increased repetitions.
AND THE WINNER IS….
At the end of the study, both groups had similar increases in muscle growth, but the increased repetitions group had a small advantage in resulting in better muscle growth in the rectus femoris. The researchers hypothesized the greater increases in rectus femoris growth were due to the higher repetition group, which resulted in greater muscle recruitment and fatigue at the end of each set of the rectus femoris resulting in greater growth. Greater increases in 1-RM strength leaned in favor of the heavyweight group compared to the increased reps group. Both groups had equal increases in leg extension endurance of about ~7 reps with no meaningful differences between the groups.(4)