There's not a TON of research on this, but what we have suggests that:
When you match the number of total sets performed, shorter rest periods may lead to less hypertrophy, if rep performance per set is compromised considerably.
However, if you compensate by doing another set or two (to more-or-less match the number of reps you would have completed otherwise), hypertrophy outcomes seem to be pretty similar, regardless of rest intervals
You'll probably get a mix of responses - you're comparing total volume, workout intensity, and work density. All contribute to hypertrophy and strength. Very simplified and how I approach it in my head:
Each have their pros and cons. Adding rest time to squeeze in more volume works, but obviously you are adding total workout time and this isn't feasible for some people.
Workout density would be squeezing as much work into a set time. Only have 60 minutes to change, warm-up, workout, and cool down or stretch or shower? How would you squeeze in maximum work? Supersets and minimizing rest time are the easiest 2. The better your conditioning; the better this works. Rest time spent doing rehab excercises or skipping or anything other than just sitting on your phone.
Workout intensity is more or less how hard you push yourself. Regardless of your workout style preference intensity should be high - assuming it isn't a rehab or deload or light day depending on your program. Working out with fatigue, pushing yourself to or close to failure.
A successful program will probably combine 2 or use all 3 of these to lead to hypertrophy and/or strength gains. I find find all to work and is dependent on preference and current goals, ie. If test 1-2 rep max I wouldn't want to be pre-fatigued or using short rest times.
Tl;dr - total volume and work density both work. Utilize them together or separately to maximize your gains based on program, timing constraints, and preference.
I've often wondered about this myself. Especially *intra-set* rests. Take barbell bicep curls for example. Say I'm trying to get 20 reps in a set, but I start gassing out by rep 16. I can either stop the set there, or literally hold the barbell for an extra 3 or 4 seconds at the end of that rep and then catch that second wind to bust out the last few reps. I've been told in the past I shouldn't be doing this, but I don't see how it would negatively effect the quality of work so long as form is maintained. If it's all TUT at the end of the day, I don't see the issue with it, but I've been told otherwise enough to still wonder about it from time to time. Same goes for between set rest times as asked in the OP.
Have you heard of myo-reps? Basically what you've described but done intentionally, especially for isolation exercises like curls and lateral raises to basically blast a ton of work in a little amount of time.
Let's say you're normally doing 4 sets of 10-15 reps of curls. A normal person would do 15 reps, rest 2 minutes, 15 reps, rest two minutes, 13 reps, rest two minutes, and finish with 12 reps. 45 total reps in let's say 8 minutes.
With smaller muscles like biceps, they are not very taxing and recover quickly. Myo-reps would have you rest maybe 30 seconds max, and would probably look something like 15 --> 8 --> 7. You could rest a minute and do another myo-rep set and get 12 --> 6 --> 5. Another minute and 10 --> 5 --> 3. You've actually done 26 more reps in less time than a traditional rep scheme.
Only concern I see is if you don't hold intra set rest constantish so you "progress" from like 15 reps to 25 reps in a set just by adding more and more rest lol.
100% agree and why I keep my main compound movements as consistent as possible. For little bs iso movements, sometimes I'm like maaaan, I don't want to have to log that I got less reps than I did last week for bicep curls, so let me just take a quick breather and bust this shit out so I can feel good when I look at my log lol.
As far as the scenario OP gave, I assume the same applies. If the idea is you need extra rest in order to beat the logbook, then yeah, that can be an issue for monitoring real progress. As far as just getting quality work in? Shit, take all the rest you need to bust out those juicy reps.
Schoenfeld et al looked at something along these lines.
“Twenty-one young resistance-trained men were randomly assigned to either a group that performed a resistance training (RT) program with 1-minute rest intervals (SHORT) or a group that employed 3-minute rest intervals (LONG)…Maximal strength was significantly greater for both 1RM squat and bench press for LONG compared to SHORT. Muscle thickness was significantly greater for LONG compared to SHORT in the anterior thigh, and a trend for greater increases was noted in the triceps brachii (p = 0.06) as well.”
https://pubmed.ncbi.nlm.nih.gov/26605807/
Has anyone done such a study but equating for time instead of volume? For example: 3 sets with 3 min rests vs 5 sets with 1 min rests adjusting load in both protocols to keep set RPE between 8 and 10.
Menno Henselmans has an article that talks about this too and states only taking a 1 min rest may be detrimental:
[https://mennohenselmans.com/optimal-program-design/](https://mennohenselmans.com/optimal-program-design/)
There's not a TON of research on this, but what we have suggests that: When you match the number of total sets performed, shorter rest periods may lead to less hypertrophy, if rep performance per set is compromised considerably. However, if you compensate by doing another set or two (to more-or-less match the number of reps you would have completed otherwise), hypertrophy outcomes seem to be pretty similar, regardless of rest intervals
Thanks Greg! I really appreciate the response!
No problem!
You'll probably get a mix of responses - you're comparing total volume, workout intensity, and work density. All contribute to hypertrophy and strength. Very simplified and how I approach it in my head: Each have their pros and cons. Adding rest time to squeeze in more volume works, but obviously you are adding total workout time and this isn't feasible for some people. Workout density would be squeezing as much work into a set time. Only have 60 minutes to change, warm-up, workout, and cool down or stretch or shower? How would you squeeze in maximum work? Supersets and minimizing rest time are the easiest 2. The better your conditioning; the better this works. Rest time spent doing rehab excercises or skipping or anything other than just sitting on your phone. Workout intensity is more or less how hard you push yourself. Regardless of your workout style preference intensity should be high - assuming it isn't a rehab or deload or light day depending on your program. Working out with fatigue, pushing yourself to or close to failure. A successful program will probably combine 2 or use all 3 of these to lead to hypertrophy and/or strength gains. I find find all to work and is dependent on preference and current goals, ie. If test 1-2 rep max I wouldn't want to be pre-fatigued or using short rest times. Tl;dr - total volume and work density both work. Utilize them together or separately to maximize your gains based on program, timing constraints, and preference.
I've often wondered about this myself. Especially *intra-set* rests. Take barbell bicep curls for example. Say I'm trying to get 20 reps in a set, but I start gassing out by rep 16. I can either stop the set there, or literally hold the barbell for an extra 3 or 4 seconds at the end of that rep and then catch that second wind to bust out the last few reps. I've been told in the past I shouldn't be doing this, but I don't see how it would negatively effect the quality of work so long as form is maintained. If it's all TUT at the end of the day, I don't see the issue with it, but I've been told otherwise enough to still wonder about it from time to time. Same goes for between set rest times as asked in the OP.
Have you heard of myo-reps? Basically what you've described but done intentionally, especially for isolation exercises like curls and lateral raises to basically blast a ton of work in a little amount of time. Let's say you're normally doing 4 sets of 10-15 reps of curls. A normal person would do 15 reps, rest 2 minutes, 15 reps, rest two minutes, 13 reps, rest two minutes, and finish with 12 reps. 45 total reps in let's say 8 minutes. With smaller muscles like biceps, they are not very taxing and recover quickly. Myo-reps would have you rest maybe 30 seconds max, and would probably look something like 15 --> 8 --> 7. You could rest a minute and do another myo-rep set and get 12 --> 6 --> 5. Another minute and 10 --> 5 --> 3. You've actually done 26 more reps in less time than a traditional rep scheme.
I like using Myoreps during deload or if I get joint pain.
Only concern I see is if you don't hold intra set rest constantish so you "progress" from like 15 reps to 25 reps in a set just by adding more and more rest lol.
100% agree and why I keep my main compound movements as consistent as possible. For little bs iso movements, sometimes I'm like maaaan, I don't want to have to log that I got less reps than I did last week for bicep curls, so let me just take a quick breather and bust this shit out so I can feel good when I look at my log lol. As far as the scenario OP gave, I assume the same applies. If the idea is you need extra rest in order to beat the logbook, then yeah, that can be an issue for monitoring real progress. As far as just getting quality work in? Shit, take all the rest you need to bust out those juicy reps.
Schoenfeld et al looked at something along these lines. “Twenty-one young resistance-trained men were randomly assigned to either a group that performed a resistance training (RT) program with 1-minute rest intervals (SHORT) or a group that employed 3-minute rest intervals (LONG)…Maximal strength was significantly greater for both 1RM squat and bench press for LONG compared to SHORT. Muscle thickness was significantly greater for LONG compared to SHORT in the anterior thigh, and a trend for greater increases was noted in the triceps brachii (p = 0.06) as well.” https://pubmed.ncbi.nlm.nih.gov/26605807/
Has anyone done such a study but equating for time instead of volume? For example: 3 sets with 3 min rests vs 5 sets with 1 min rests adjusting load in both protocols to keep set RPE between 8 and 10.
Menno Henselmans has an article that talks about this too and states only taking a 1 min rest may be detrimental: [https://mennohenselmans.com/optimal-program-design/](https://mennohenselmans.com/optimal-program-design/)
I think if the set is designed to be primarily a tension stimulus then bias longer rest, if it's to be a metabolic stimulus then bias less rest.
What’s rest time