hey homonunculus, hows life? the study that i was referring to in regards to the negative and the two second lowering is in this study. (med. sci. sports, 33: 196-200, 2001) to give a overview to those who do not feel like looking it up they state that doing negatives fairly quickly with a increased load activated more muscle fiber than using the less weight and doing the negative more slowly. they used mri imaging. the study was performed at the university of southern california. a similar study was performed at a unversity in georgia with the same results. when i find it i will pm ya.
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Found the study (Kulig et al.) and have it here at home, actually. Looks like they used the SAME load for the different conditions, but the # of reps. different. (They compared 1 up , 1 down vs. 1 up, 5 down) There was no effect of the different protocols in activation of the two elbow flexors (b. brachii and brachialis), so the overall activation (both muscles pooled together did not differ. The neat part was that slow protocol preferentially hit the brachialis vs. the biceps. Interestingly, the O-Hagan ref. I think I cited before (see below) found that doing the eccentric during a training program increased brachialis but not biceps size!
BTW, who is your friend? He/ She is lucky to work with Frank Shellock - when it comes to MRI, he's da Man!
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i unfortunately could not pull up the reference study(s) that you had written down. i will try again later at home. can you give me an idea of what the study revealed?
HEre's the Hather et al. ref - probably the strongest in favor of the necessity of the eccentric contraction for increasing muscle (fiber) size.:
1. Hather, B. M., P. A. Tesch, P. Buchanan, and G. A. Dudley. Influence of eccentric actions on skeletal muscle adaptations to resistance training. Acta Physiol Scand 143: 177-185, 1991.
Three different training regimens were performed to study the influence of eccentric muscle actions on skeletal muscle adaptive responses to heavy resistance exercise. Middle-aged males performed the leg press and leg extension exercises two days each week. The resistance was selected to induce failure within six to twelve repetitions of each set. Group CON/ECC (n = 8) performed coupled concentric and eccentric actions while group CON (n = 8) used concentric actions only. They did four or five sets of each exercise. Group CON/CON (n = 10) performed twice as many sets with only concentric actions. Eight subjects did not train and served as controls. Tissue samples were obtained from m. vastus lateralis using the biopsy technique before and after 19 weeks of training, and after four weeks of detraining. Histochemical analyses were performed to assess fibre type composition, fibre area and capillarization. Training increased (P less than 0.05) Type IIA and decreased (P less than 0.05) Type IIB fibre percentage. Only group CON/ECC increased Type I area (14%, P less than 0.05). Type II area increased (P less than 0.05) 32 and 27%, respectively, in groups CON/ECC and CON/CON, but not in group CON. Mean fibre area increased (P less than 0.05) 25 and 20% in groups CON/ECC and CON/CON, respectively. Capillaries per fibre increased (P less than 0.05) equally for Type I and Type II fibres.Capillaries per fibre area for both fibre types, however,increased (P less than 0.05) only in groups CON and CON/CON. The changes in fibre type composition and capillary frequency were manifest after detraining.(ABSTRACT TRUNCATED AT 250 WORDS) Biomedical and Environmental Laboratories Bionetics Corporation Kennedy Space Center FL
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as for the tut study. i know it was in the strength cond. journal. i used to get it when a buddy of mine was studying exercise phys. he would toss them to me. i will e mail him tonight for the info. the study basically looks at olympic lifters and quad mass. the study showed the lifters performing multiple sets of 1- 5 reps , done in fairly explosive fashion produced hypertrophy similar to lighter loads for longer tut. btw none of the work sets lasted more than 10 seconds. their conclusion was, if memory serves, that the higher the tension the lower tut was needed. in other words, tension and load made up for the "lack" of tut. "whats wrong the concept of volume in the context of intensity?"... EXACTLY.
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Would be cool if you could find that ref. SOunds like it was a x-sectional study, though(?)...
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i tyhink the problem lies in the fact that we know negatives produce results. but, it has been taken a bit far. if a person is doing a 10 second concentric and then following it up with a ten second negative...well it is being taken too far. wheres the load? where is the tension? if one can do a ten second positive, i sure as heck guarantee that he is not taxing the fibers on the negative much. i do agree with what you have written in regards to the higher threshold fibers being more activated in the negative. i am just saying that the negative could be faster if the load was higher and still get the fibers we discussed. like we said..CONTROLLED. LOL unfortunately, doing PURE negatives with supra max weights will produce great gains in size and stregth but, now find two of your closest buddies who are willing to help you get it to the top...well they will not be your close friends for long. it just is not very realistic. lol i will try to get you those other studies in regards to tut tonight. stay safe
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Cool, Thanks, man. Here's another you might be interested in. THis one might interest you, too. I think this equipment (I looked, but couldn't find it in the artible) is like the LIfe Fitness Computerized equipment:
1. Brandenburg, J. P., and D. Docherty. The effects of accentuated eccentric loading on strength, muscle hypertrophy, and neural adaptations in trained individuals. J Strength Cond Res 16: 25-32., 2002.
The purpose of this study was to compare the strength and neuromuscular adaptations for dynamic constant external resistance (DCER) training and dynamic accentuated external resistance (DAER) training (resistance training employing an accentuated load during eccentric actions). Male subjects active in resistance training were assigned to either a DCER training group (n = 10) or a DAER training group (n = 8) for 9 weeks. Subjects in the DCER group performed 4 sets of 10 repetitions with a load of 75% concentric 1 repetition maximum (RM). Subjects in the DAER group performed 3 sets of 10 repetitions with a concentric load of 75% of 1RM and an eccentric load of approximately 120% of concentric 1RM. Three measures reflecting adaptation of elbow flexors and extensors were recorded pretraining and posttraining: concentric 1RM, muscle cross-sectional area (CSA), and specific tension. Strength was assessed at midtraining periods. No significant changes in muscle CSA were observed in either group. Both training groups experienced significant increases in concentric 1RM and specific tension of both the elbow flexors and extensors, but compared with DCER training, DAER training produced significantly greater increases in concentric 1RM of the elbow extensors. These results suggest that, for some exercises, DAER training may be more effective than DCER training in developing strength within a 9-week training phase. However, for trained subjects, neither protocol is effective in eliciting muscle hypertrophy.
Ref's for ya:
1. O'Hagan, F. T., D. G. Sale, J. D. MacDougall, and S. H. Garner. Comparative effectiveness of accommodating and weight resistance training modes. Med Sci Sports Exerc 27: 1210-9., 1995.
Hather, B. M., P. A. Tesch, P. Buchanan, and G. A. Dudley. Influence of eccentric actions on skeletal muscle adaptations to resistance training. Acta Physiol Scand 143: 177-185, 1991.
-Randy