Date: Wed, 19 Jun 96 From: aleck@alexandros.cperi.forth.gr (Alecksandros Alexopoulos) Subject: Re: Rest Periods On the subject of rest time between sets. It is well known that the rest time depends on the weight intensity of the exercise (%1-rep-max). The higher the intensity the more rest you need. {I dont believe in increasing intensity by trying to reduce the rest period. Sure tests have shown this gives you elevated GH-levels, but so does starvation or illness or any stress situation. The question is does it help you get stronger/bigger (or, when your GH goes up what happens to your cortisol/testosterone ratio over the next 24 to 48 hrs?). I dont believe in fatigue. I follow a moderate volume high intensity program. } So if we aim to rest just enough that our next set is effective how much should we rest? A general rule follows: ---------------------------------- | For 8-12 rep sets rest 1-2 min | | For 5-8 rep sets rest 2-3 min | | For 1-5 rep sets rest 3-5 min | ---------------------------------- If this is good enough fine - skip the rest of this post. --- What follows is some thoughts on how to figure out the "best" rest-time. Lets consider two measures of intensity: Iw = weight/1RM weight intensity Ir = reps/max-reps rep intensity (another important measure is volume intensity but thats another story...) Iw indicates the % of the max weight you can use Ir indicates the % of the max reps you can use at a certain weight If your 1RM is 200lbs and you're working at 150lbs then Iw=150/200=0.75 If your max reps at 150 is 12 and you're doing sets of 8 then Ir=8/12=0.67. Obviously you would need more rest if you increased Iw or Ir. But what if you increase one and decrease the other? Compare the following two 4set workouts: Iw=0.90% Ir=0.70% (max reps 3): 4X2 @ 180 lbs Iw=0.70% Ir=0.90% (max reps 15): 4x13 @ 140 lbs Whats the least rest you need in each case in order to complete all 4sets? (In similar workouts I've used about 4min for the first and 3min for the second workout.) Suppose you need 6min rest between two consecutive 1RMax sets. Then one is tempted to define a combined intensity I=Iw*Ir and assume a linear variation of rest-time with combined intensity. This would give: Time = 6*Iw*Ir min For the above two workouts you would get Time=3.78min. Not bad... This may not be good enough (maybe Iw should be weighted more than Ir) so one can consider a general expression: Time = MaxTime * Iw^p * Ir^q where p>q. Instead of trying to determine an estimate for p and q (p=1.2 and q=0.8 look good....) I'll just give a table with the rest-times in minutes that I used in my last cycle. -------------------------------------------- % weight | max | % rep - intensity intensity|reps | 100 90 80 70 60 -------------------------------------------- 100 | 1 | 6 95 | 2 | 5 4 91 | 3 | 5 4 3.5 88 | 4 | 5 4 3.5 3 84 | 5.5 | 4.5 4 3.5 3 3 81 | 7.5 | 4 3.5 3 2.5 78 | 10 | 4 3 2.5 74 | 12 | 4 3 2.5 2 72 | 14 | 3 69 | 17 | 3 2.5 2 60 | 25 | 1.5 Now I'm not saying that these are optimal rest-times. The one main point that I think should be made is that rest-time should increase not only when weight-intensity increases, but also when rep-intensity increases. Thats all for now. Aleck ------------------------------ From: TMccull230@aol.com Date: Fri, 28 Jun 1996 Subject: Re: Rest Periods > >It is well known that the rest time depends on the weight intensity of the > >exercise (%1-rep-max). The higher the intensity the more rest you need. >>p=1.2 and q=0.8 Time = MaxTime * Iw^p * Ir^q where p>q.Time = 6*Iw*Ir >>min I=Iw*Ir >Is that so? I had never heard it before, to this date I always believed it >had to do with set intensity ( = Ir, rep intensity). Please, elaborate. >This is complete garbage. With 8-12 rep sets it's much easier to approach >maximum "Ir", which will definitely increase the need for rest. Guys...quit trying to make a rocket science out of weight training. Weight lifting is much simpler than a bunch of formulas and theories. There are reasons why bodybuilders and powerlifters have always trained the way they do. Simple, BECAUSE IT WORKS. Scientist only attempt to justify these training protocols through complicated formulas and theories. The fact is, despite science these training protocols still work. Let's look at things this way. I squat over 700lbs for a single, now if I were to load up the bar to say, 135 lbs and do a set of 12, am I going to have to rest as long as if I loaded up the bar and squatted a set of 725 lbs for a single? According to you 135 x 12 reps = 1350 lbs a total set volume 53% higher than 725 lbs., therefore, I should need to rest longer. My suggestion is that you go try this for yourself and then reexamine your statement. Does it really matter why? Do we really feel the need to justify this with scientific formulas and theories? Well, here are some scientific theories for you: PCr has been shown to degrade at its quickest during the first 10 seconds of exercise. I would certainly think that it would be very hard to do more than 3-5 good reps in 10 sec. After this time glycogen becomes of more and more importance to resynthesizing ATP as the exercise moves more towards the aerobic phase. In any case, the degradation rate however, is very dependent on the intensity or resistance of the exercise. Now there are other things that could possibly determine how long we need to rest before full recovery. (Actually, science has yet to determine optimal rates). Anaerobic capacity, meaning the availability of immediate PCr and the availability of muscle glycogen would probably make a big difference, huh? What about the state of training? Someone that is highly anaerobically trained might recover a little quicker. What about the individual training protocol used by the athlete. It has been shown that powerlifters (who train with high intensity and low reps) demonstrate selective hypertrophy of more type II muscle fibers than a bodybuilder (who trains lower intensity and higher reps). Bodybuilders have been shown to demonstrate a little less selective hypertrophy of type II muscle fibers and little more type I fibers. It is a well thought that PCr is degraded at a much quicker rate in type II fibers that type I and resynthesized at a much slower rate too. Could that possibly effect rest periods? How about the number of sets done. Would 3 sets require anymore time than one set? Of course it would! Now we don't have to worry too much about lactate accumulations in one short duration set, but 2 and 3 we surely may. Not only is it increasingly harder to get rid of lactate, but ATP resynthesis also slows. Does intensity (resistance) affect this? Again, of course it does. Now for suggested times to replenish ATP, I have found anything from 2.5 m - 5 min. suggested. Of course, once again, this is very dependent on the intensity of the exercise. You also need to take into consideration what your training goals are. These longer time periods might be optimal for those who are interested in gaining power and strength, but they may not be ideal for those who are interested in hypertrophy. Research studies have shown that 30s - 1.5 m rest periods may be more optimal for hypertrophy gains only because the stress better stimulates anabolic hormone production. Here are some other suggested times for replenishing energy stores I have found. Recovery of ATP requires three to five minutes, and PCr recovery occurs within eight minutes. Without complete recovery, subsequent exercise intensity will be effected. Now, with body building this may not be of any importance because it may be more beneficial to stimulate GH and testosterone production. However, to a strength or power athlete this certainly will make a big difference. I also found that high intensity exercise also results in lactic acid accumulation, as mentioned earlier, which will cause disturbances in the muscle (H+ and K+) contributing to muscle failure. It is thought that the time needed for cellular lactate efflux is from four to ten minutes. This simply means that it may take from four to ten minutes to completely get rid of the lactic acid accumulations in the muscle after a set of high intensity work. The optimum rest period length, yet to be determined, likely depends on the type of exercise, number of repetitions per set, and other factors. By looking at what we do know, it is probable that the higher the intensity and the lower the volume, the more rest would be required between sets. Thus, it would seem that if it is those big strength gains you are after, more time spent resting between sets may be better than less time. Tom McCullough Excel Sports Fitness, Inc. "A New Dimension in Weight Training and Nutrition" 5675 Purple Sage Suite # 506 Houston, Tx 77049 (713)458-4313 voice/fax/page E-mail: TMccull230@aol.com From: TMccull230@aol.com Date: Sun, 25 Aug 1996 Subject: Rest Periods Revisited A few months ago there was a discussion going on about proper rest periods between sets. To me this answer to this question is very simple, although a bit anecdotal. However, if you have ever walked into a gym and actually lifted weights, you should easily find that the closer you get to your 1RM (single rep max) the more recovery you need for the next set. Never the less, there were some that insisted on answering this question by turning weight lifting into a rocket science. We toss about several magical formulas and never did reach any conclusions. Well for all of those that are still interested in proper rest periods, it's explained in the literature as follows: As strength gains increase, rest periods also increase, which is related to relative training intensity. For those of us who absolute insist on a scientific explanation, the available research explains this theory by saying that ATP recovery actually requires 3 to 5 minutes, and phosphocreatine recovery occurs within 8 minutes. Both directly influence subsequent exercise intensity. 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 produce marked increases in serum lactate. The time needed for cellular lactate ion and H+ efflux has been shown to be 4 to 10 minutes. So in order to be complete recovered for the next set one must surely consider the above mentioned facts. It should be noted that optimum rest periods for a given intensity have not been established. But it is obvious that the type of exercise, number of reps per set, and other factors may will affect this time. However, if you are working with 90%+ 1RM, I would say it would be a safe bet to wait between 3-5 minutes. If you are doing multiple sets at that intensity I would push the time up to around 6-8 minutes to allow for complete efflux of lactic acid accumulations. 1. Fleck, SJ and Kramer, NH (1987). Designing Resistance Training Programs. Champaign, IL: Human Kinetics. 2. Garhammer, J (1987). Strength Training. New York: Harper & Row. 3. Gorden, SC, et.al. (1994). Effect of acid base balance on GH response to acute high-intensity cycle exercise. Journal of Applied Physiology. 76(2):821-829. 4. Harris, RC, et.al. (1976). The time course of phosphocreatine resynthesis during recovery of quadriceps muscle in man. Pfug. Arch. 97:392-397. 5. Hermansen, RC, et.al. (1972). Blood and muscle pH after maximal exercise in man. Journal of Applied Physiology. 32:304-308. 6. Hultman, E and Sjoholm, H. (1986). Biomechanical Causes of Fatigue. In:Human Muscle Power. NL Jones, N McCartney, and AJ McComas, eds. Champaign, IL: Human Kinetics. 7. Jones, NL (1990). [H+] control in exercise: Concepts and controversies. In: Biochemistry of Exercise VII. Taylor, Gollnick, Green, Ianuzzo, Noble, Metivier, and Sutton, eds. Champaign, IL: Human Kinetics. 8. Kraemer, WJ, et.al. (1990). Hormonal and growth factor responses to heavy resistance exercise protocols. Journal of Applied Physiology. 69:1442-1450. 9. Kowalchuk, JM, et.al. (1988). Factors influencing hydrogen ion concentration in muscle after intense exercise. Journal of Applied Physiology. 65:2080-2089. 10. Saltin, B (1990). Past, present, and prospective. In: Biochemistry of Exercise VII. Taylor, Gollnick, Green, Ianuzzo, Noble, Metivier, and Sutton, eds. Champaign, IL: Human Kinetics. Tom McCullough Excel Sports Fitness, Inc. 5675 Purple Sage, Suite # 506 Houston, TX 77049 (713) 458-4313 voice/fax/page E-mail: TMccull230@aol.com