What length of rest is best for hypertrophy/strength

[ILiftBig]

How many times have we heard that short rest periods (~45s) are best for hypertrophy? Is this necessarily true or does the body eventually adapt to this stress level?

Journal of Strength and Conditioning Research:Volume 23(1)January 2009pp 62-71
The Effect of Resistive Exercise Rest Interval on Hormonal Response, Strength, and Hypertrophy With Training

[Original Research]
Buresh, Robert1; Berg, Kris2; French, Jeffrey3

1Department of Health, Physical Education, and Sport Science, Kennesaw State University, Kennesaw, Georgia; 2School of Health, Physical Education, and Recreation, University of Nebraska at Omaha, Omaha, Nebraska; and 3Department of Psychology, University of Nebraska at Omaha, Omaha, Nebraska
Address correspondence to Robert Buresh, [email protected].

Abstract

Buresh, R, Berg, K, and French, J. The effect of resistive exercise rest interval on hormonal response, strength, and hypertrophy with training. J Strength Cond Res 23(1): 62-71, 2009- The purpose of this study was to compare the effects of different between-set rest periods (1 and 2.5 minutes) on changes in hormone response, strength, arm cross-sectional area (CSA), thigh muscular cross-sectional area (MCSA), and body composition during a 10-week training period. Twelve untrained males (24.8 ± 5.9 years) engaged in resistance training using either 1 minute (short rest [SR], n = 6) or 2.5 minutes (long rest [LR], n = 6) of rest between sets, with a load that elicited failure on the third set of each exercise. Body composition, thigh MCSA, arm CSA, and five-repetition maximum (RM) squat and bench press were assessed before and after training. Blood samples were collected after exercise in weeks 1, 5, and 10. In week 1, postexercise plasma testosterone levels were greater in SR (0.41 ± 0.17 mmol·L-1) than in LR (0.24 ± 0.06 mmol·L-1, p < 0.05), and postexercise cortisol levels were greater in SR (963 ± 313 mmol·L-1) than in LR (629 ± 127 mmol·L-1, p < 0.05). Week 1 postexercise GH levels were not different (p = 0.28). The differences between hormone levels in weeks 5 and 10 were not significant. Arm CSA increased more with LR (12.3 ± 7.2%) than with SR (5.1 ± 2.9%, p < 0.05).

Conclusions:There were no differences in strength increases. These results show that in healthy, recently untrained males, strength training with 1 minute of rest between sets elicits a greater hormonal response than 2.5-minute rest intervals in the first week of training, but these differences diminish by week 5 and disappear by week 10 of training. Furthermore, the hormonal response is highly variable and may not necessarily be predictive of strength and lean tissue gains in a 10-week training program.

 

[Pleonastic]

I read in Mens Health once they had a guy form "Worlds Strongest Man" competition say how he trains: He said short rest time and heavy sets to failure. He was training for specific events though where they dont get lots of recovery time moving from different stages of events. So I think he was training with short rest to ttrain his recovery speed as well.


To me pure strength building would best be done with max rest in between sets like 3-5 whole minutes. So you can hit damn near the same workload each time to your best ability.

 

[ILiftBig]

I read in Mens Health once they had a guy form "Worlds Strongest Man" competition say how he trains: He said short rest time and heavy sets to failure. He was training for specific events though where they dont get lots of recovery time moving from different stages of events. So I think he was training with short rest to ttrain his recovery speed as well.


To me pure strength building would best be done with max rest in between sets like 3-5 whole minutes. So you can hit damn near the same workload each time to your best ability.

Yes, most magazines have really promoted this 45 second rest period to stimulate growth. Apparently it is good for a while and then longer rest periods are the ticket. It's probably best to rest 3-5 minutes and up the weight from the get go.

 

[rabican]

so like 1min rest time is best for say a speed day or higher rep day but obviously you will need more time between sets if your going heavy...i know i do.

 

[msucurt]

this is what i do...

power (3-5) rest up to 5min to let ATP regenerate
repetitions (10-12) - 2to3min rest
shock/superset/dropsets - no rest. Just lift for 10reps. drop the weight. Grab another weight and get after it.

 

[ILiftBig]

so like 1min rest time is best for say a speed day or higher rep day but obviously you will need more time between sets if your going heavy...i know i do.

Being an ex-powerlifter. I always said do your next set when you feel ready. With speed work the load should be fairly light so you recovery time should be pretty quick. I know when I did speed work, most of the time I felt ready to go again in 30-45 seconds.

The reason behind this that in order to be able to recover from a set you have to give the body time to regenerate ATP. Naturally the heavier the load the more time it takes. In those heavy sets with load 85%+ it takes about 3-5 minutes to completely regenerate ATP levels. However, it can take up to 8 minutes for phosphocreatine stores to completely recover. Here is where creatine supplementation plays an important factor in quicker recovery times.

High intensity exercise also results in lactic acid and hydrogen ion (H+) accumulation and can disrupt sodium (Na+), potassium (K+), calcium (Ca++), magnesium (Mg++), and chlorine (Cl-1), and other anions such as proteins and phosphate ions resulting in a lowered intracellular pH. These disturbances can contribute to muscle fatigue. Shorter rest periods of less than one minute between sets can also produce marked increases in serum lactate. These buildups can also cause muscle fatigue. The time needed for cellular lactate ion and H+ efflux has been shown to be 4 to 10 minutes.

So to make this simple and use a lot less words, the heavier the weight the more you need to rest. Speed work can be done with no problems with much shorter rest periods. Heavy sets of 85% + should optimally be doe with rest periods of 3-5 minutes.