Rev Bras Med Esporte Vol. 11, N - PDF document

Rev Bras Med Esporte Vol. 11, Nº 2 – Mar/Abr, 2005 1.Exercise Physiology Laboratory – UniFMU University Center, São Pau-2.Biomedics Sciences Institute – University of São Paulo, São Paulo, Bra-Received in 12/10/04. 2 version received in 5/1/05. Approved in 4/3/05.Correspondence to: Prof. Dr. Marcelo Saldanha Aoki, Prédio 20 – Facul-Rua Galvão Bueno, 707 – 01506-000 – São Paulo, SP. E-mail: salda- Key words:Creatine. Supplementation. Concurrent exercise. Interference. The objective of this study was to verify if creatine Sixteen female university students were divided Vol. 11, Nº 2 – Mar/Abr, 2005high-intensity exercise, the objective of this work was to verify theSixteen female Physical Education students (20.1 ± 1.9 years)of strength exercises at least three times a week as well as endur-adopted for the participation in this study was the minimum periodthe consumption of other nutritional supplements and controlledbeings (CEPSH) of the Biomedics Sciences Institute – Universityused and agreed in participating voluntarily in the study, signing aLater, the percentile value equivalent to 80% of the 1-RM valuestant step rhythm during the entire activity, the test started with acommand voice “ready, go”, with chronometer turned on simulta-neously. The test ended with a whistle sound.tered during seven days. The group placebo was used as controlplemented with creatine; however, this group received only carbo-Two data collections were performed in distinct days 12 daysaway from one another. At the beginning of the supplementation (80% of the1-RM). Twelve days after supplementation (creatine or placebo),both test (1-RM and maximum repetitions) were once again per-exercise (running) on the strength development in groups placeboVA – two way) (time factor x supplementation factor) followed bythe Tukey test (GraphPAD software). The minimum significanceRESULTSexecution of the endurance exercise (table 1). The 1-RM value/body weight ratio also remained unchanged in relation to groups) and at the end of the experiments TABLE 1 inprevious performance of endurance exercises) shortly after the endurance exercisePlacebo (n = 8)Creatine (n = 8)1-RMWeight1-RM:1-RMWeight1-RM:(kg)(kg)Weight(kg)WeightInitial180.4 ± 20.159.2 ± 4.93.0 ± 0.3191.4 ± 22.560.9 ± 5.63.2 ± 0.5 Final179.1 ± 18.358.6 ± 4.53.1 ± 0.4189.7 ± 20.261.8 ± 5.43.1 ± 0.4Values expressed as average ± standard deviation. However, in the maximum repetitions test, a decrease on theperformance of the aerobic exercise was observed in the two last set: 9.0 ± set: 8.9 ± 2.9 and 3 set: 8.3 ± 3.3 set: 7.6 ± 2.6; set: 4.3 ± 2.9*; p set: 4.6 ± 2.3*; p )( set: 9.8 ± 2.9 and 3 set: 9.7 ± 3.5 set: 9.5 ± 2.7 and 3 set: 9.0 ± 3.0). At the endof the experiment, after the endurance exercise, the average num-ber of maximum repetitions performed by the group creatine inthe last two sets was higher than that of the group placebo (table TABLE 2Determination of the number of maximum repetitions performed in leg press and at 80% of the 1-RM value in groups placebo and creatine at the shortly after the endurance exercisePlacebo (n = 8)Creatine (n = 8)Initial9.0 ± 2.48.9 ± 2.910.2 ± 2.29.8 ± 2.9 Final7.6 ± 2.64.3 ± 2.9*4.6 ± 2.3*10.9 ± 2.99.5 ± 2.7Values expressed as average ± standard deviation.*different from the group placebo at the beginning of the experiment (p )different from the group placebo at the end of the experiment (p ) Regarding the 20-minutes running test, no difference was ob-served on the performance of both groups (table 3). Rev Bras Med Esporte Vol. 11, Nº 2 – Mar/Abr, 2005the muscle would have reduced capacity of developing tension who verified that the strength development in theexercise shortly before the resistance training. In the same study,by the previous endurance training. According to the authors, theHowever, previous evidences obtained in our laboratory demon-the performance of the concurrent training (aerobic training per-In the present study, the results observed demonstrate that thethe 1-RM test. Recently, in another study conducted in our labora-the 1-RM test. However, still in this study, we verified that thecreatine intake increased the capacity of performing maximum rep- didsupplementation either. As in our study, Earnest only veri-fied increases on the capacity of performing maximum repetitionsmaximal effort (~6-8 seconds), as in the case of the 1-RM test, bebe able to supply this demand. Consequently, the group submittedto creatine supplementation would not present a better perfor-In relation to the capacity of performing maximum repetitionsmote a depletion of the energetic substrates, thus generating aperforming maximum repetitions (80%-1-RM) in the leg press at ions) and/or the reduction observed thatrest situation) and the muscular acidosis (21.3 mmol.kg of wet series ofmaximum repetition at 80% of the 1-RM value. These authors also ions concentra-that the CP reduction degree (50% in relation to the rest situation) series (62% in relation tothe rest situation). Reinforcing this hypothesis, the lactate produc- series – 21.3 wet weight 3 series – 27.4 mmol.kg wet weight) series may be related withmentioning the buffering capacity exerted by the ATP-CP systemThe immediate re-phosphorylation of ADT into ATP through the CP ionthe performance in the subsequent maximum repetitions test indemonstrated that the previous performance of endurance exer-fied in this study, that the creatine supplementation is able to nul-lify the adverse effect induced by the endurance exercises on theof the 1-RM value. These results suggest that the ATP-CP systemat high intensity.ter, to MS Prof. Vagner Raso for the aid in the statistical analysis and toPhD Prof. Reury Frank P. Bacurau for the aid in the results discussion. All the authors declared there is not any potential conflict of inter- ests regarding this article. TABLE 3Evaluation of the distance covered in the 20-minutes running test performed Placebo (n = 8)Creatine (n = 8) Distance covered (m)3,846 ± 3103,759 ± 275Values expressed as average ± standard deviation. Vol. 11, Nº 2 – Mar/Abr, 20051.Leveritt M, Abernethy PJ, Barry BK, Logan PA. Concurrent strength and endur-ance training. A review. Sports Med 1999;28:413-27.2.Aoki MS, Pontes Jr FL, Navarro F, Uchida MC, Bacurau RFP. Suplementação de sobre o3.Gomes RV, Matsudo SMM, Almeida VCS, Aoki MS. Suplementação de carboi-4.Hickson RC. Interference of strength development by simultaneously training5.Kraemer WJ, Patton JF, Gordon SE, Harman EA, Deschenes MR, Reynolds K, et6.Craig BW, Lucas J, Pohlman R, Stelling H. The effects of running, weightlifting7.Dudley GA, Djamil R. Incompatibility of endurance and strength training modes8.Hennessey LC, Watson AWS. The interference effects of training for strengthand endurance simultaneously. 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