I remember when I saw Ronnie Coleman’s training DVD Cost of Redemption, I highly recommend purchasing this DVD if you haven’t. It includes Ronnie’s workouts include 160 lbs Dumbbell shoulder presses, 800 lbs Squats, 2,250+ lbs Leg Presses, 495 lbs Bench Presses, 75 lbs Alternate Curls and more!! Here is what’s really interesting, Ronnie sure as hell does not train like a bodybuilders in those DVD’s and yet he was a 310 pound mass monsters. He trained incredibly heavy, yet he was not following the traditional 60 second rest periods for muscle mass principle. In Blood and Guts, Dorian would rest sometimes up to 5 minutes after squats, after spending some time with Branch and talking to Bryan Dobson at Metroflex Gym in Arlington, TX about how Ronnie trained, they trained very hard but often took anywhere from 3 to 5 minute rest periods. All of these champions certainly don’t train with the traditional bodybuilding routine that used moderate weight with short rest periods (60 seconds or less) yet all of these guys are built like brick shithouses!! So if short rest periods as preached for some many years are the guy to muscle growth than why the fuck are these guys so big?. In this month’s Journal of Sports Medicine, there was a review of 35 studies examining the both acute responses and chronic adaptations, with rest interval length as the experimental variable. By tweaking your rest interval duration, you can make some serious gains in strength and size, but it not what has been traditionally thought of by bodybuilders. By tweaking your training routine, now you can!
The existing research demonstrates that altering the rest periods between sets can cause both acute and chronic adaptations in both the endocrine and nervous system5-7. By getting stronger, you will gradually begin to be able to use heavier weights which will allow for greater tension on a muscle and more muscle growth. One of the more intriguing study regarding resistance exercise and rest duration involved college football players; one group rested 1 minute between sets while the other group rested 3 minutes between sets. The group that rested 3 minutes between sets was able to complete 10 repetitions between sets while the 1 minute group was not able to complete the required 10 reps8. This suggests that resting longer will allow you to handle a greater workload during a workout…I am sure you are saying..well no shit! Let’s examine some of the research studies examining the role of rest period duration on the amount of weight you can handle in a session:
- Researchers compared 30-second and 1- and 2-minute rest intervals on the number of repetitions completed for the squat and bench press over five sets with a constant 15RM load. Significant declines in the number of repetitions occurred between the first and the fifth sets, irrespective of the rest interval. For both exercises, the 2-minute rest interval resulted in significantly greater repetitions versus the 30-second rest interval. These results suggest that when short rest intervals are utilized to develop muscular endurance, the intensity (i.e. load) may need to be progressively lowered over subsequent sets to sustain repetitions within the range conducive to this training goal. Future research should establish the extent to which the resistance should be lowered between sets in order to sustain repetitions for muscular endurance training9. So bodybuilders are not looking to build endurance in the offseason so why use short rest periods?
If you are wondering what influences muscle recuperation between sets for maintaining power it mostly points to phosphocreatine (PCr) levels in muscle. Physiological levels of PCr take 4 minutes to recover10; if you start a set when PCr levels have not recovered than hydrogen ions or lactic acid builds up in the muscle and muscle strength is reduced. So remember that, if you want full Creatine reserves for your next lift, you need at least 4 minutes of rest between sets! It is well established that a reduction in pH which causes large increases in lactic acid reduces muscle strength11. From a time perspective, using short rest periods allows for greater volume at the cost of using lowered weights; yet you may be able to significantly enhance muscle hypertrophy by a spending longer amount of time in the gym but using longer rest periods to spur new increases in muscle growth as you would be able to place more tension on the muscle by using heavier weights yet resting longer between sets so you can keep using the heavier poundage’s. For example, a study examined the effect of rest period duration on squat performance using 1, 3, and 5 minute rest periods. After 1 minute rest periods, 75% of the groups using 1 minute rest periods completed the full second set; whereas 88% of the of the group completed the second set while 94% of the group completed the second set in the 5 minute rest group12. I often change my rest period duration throughout the week, if I am rushed for time, those 1 minute rest periods are great for getting in and out of the gym, but on Saturday if I have a little bit more time, I extend my rest duration to 3-5 minutes which means I am in the gym longer but I was able to complete more reps with a heavier weight which results in more tension overload on that day.
Do acute Increases in Anabolic Hormones affect Muscle Hypertrophy?
Back in the 90’s every trained which 60 second rest periods because it was overwhelming clear that short rest periods increased GH and testosterone1-3, however as years went by only a few studies have been able to validate that short rest periods increase muscle hypertrophy. Remember, the acute anabolic hormone response lasts very shortly before returning to baseline again. When I was in graduate school, my graduate advisor Dr. Bammon opened my eyes to intramuscular growth factors being the key for muscle growth. In this month’s Journal of Applied Physiology, another study came out suggesting that short rest periods do not increase muscle hypertrophy. They had men train in either a low exercise training condition or a high exercise training condition. The way the researchers designed the study was brilliant! The experimenters assigned men in the low hormone condition (LH) to one arm performed arm curl exercise only, while in the high hormone condition (HH) the contralateral arm performed the same arm curl exercise followed immediately by a bout of leg resistance exercises designed to elicit large increases in circulating hormones. Participants consumed 18 g of whey protein immediately before exercise and 18 g at 90 min after absence and presence of elevated hormone concentrations as well as to reduce variability in nutrition surrounding the exercise bout. Blood samples were taken immediately after the end of each trial. The researchers found that including legs at the end of the arm workout increased GH, IGF-1, and testosterone as expected, but there no increases in strength or muscle hypertrophy in the high hormone group as exposed to the low hormone group. They did also not find out changes in protein synthesis despite the marked increases in acute anabolic hormones. This data suggest that exercise-induce hormone elevations do not stimulate muscle protein synthesis and are not necessary for hypertrophy13. The researchers concluded just as my graduate professor Dr Bammon told me; local mechanisms (intramuscular IGF-1, myostatin, androgen receptor, ect )are of far greater relevance in regulating muscle protein accretion occurring with resistance training, and that acute changes in hormones, such as GH, IGF-1, and testosterone, do not predict or in any way reflect a capacity for hypertrophy. I have no doubt that using short rest periods is useful for burning fat as you approach the upcoming contest and maybe helpful for stripping that last bit of fat off, but I don’t see how incorporating short rest periods year round could be helpful.
Throwing the weights on the bar can lead to some use of muscle fibers that can’t be recruited during lighter weight exercises. In exercise physiology there is the Size Principle which states whereby smaller motor units that typically innervate the less fatigable type I muscle fibers are activated with low effort activities (e.g. lower percentages of 1RM) whereas larger motor units that primarily innervate the greater force-generating type II fibers are recruited with higher effort activities (e.g. higher percentage of 1RM or with fatigue); more importantly type II fibers, which generally exhibit a greater hypertrophic response than type I fibers. With this basic fact, realize that when you lift lighter, first all the type I fibers are activated first, then the type II fibers are activated as the muscle fibers tire out. When you lift heavier, the muscle fibers begin to immediately utilize type II fibers for activation. Interestingly, vascular occlusion studies which are found to result in large increases in type II muscle fibers when performed. Vascular occlusion accelerates local metabolically induced fatigue and hastens the recruitment of type II muscle fibers to maintain work output, has been demonstrated to elicit an increase in muscle protein synthesis.
In conclusion, if you’re not changing your rest period length, you may be missing out on some gains in both strength and size. Using shorter rest periods might be advantageous when competitions are coming closer so you can enhance GH secretion for fat loss, however the research can validate that short rest periods are useful for adding muscle mass and size. It’s important to change up your routine, which means your rest period length as well. Try spending some time using longer rest periods and see if you can’t get some added size out of it. The review paper mentioned in the introduction mentioned that when training for muscular strength with loads smaller than 90% of 1RM (up to 50%) for multiple sets, 3- to 5-minute rest intervals are necessary to maintain the number of repetitions performed per set within the prescribed zone without great reductions in training intensity. The acute expression of muscular power was best maintained when including 3- or 5-minute rest intervals versus 1-minute rest intervals between sets.
by Robbie j Durand, M.A.
source:musculardevelopment.com
