Recovery of skeletal muscle contractility after high- and moderate-intensity strength exercise |
| |
Authors: | Truls Raastad Jostein Hallén |
| |
Institution: | (1) The Norwegian University of Sport and Physical Education, P.O. Box 4014 U.S., 0806 Oslo, Norway e-mail: trulsr@brage.idrettshs.no Fax: +47-22234220, NO |
| |
Abstract: | To examine neuromuscular fatigue and recovery, ten male strength athletes mean (SE) 27.5 (1.4) years] performed a moderate-
and a high-intensity strength exercise protocol. In the high-intensity protocol, the load was 100% of the subject's three-repetition
maximum (3-RM) for squats and front squats, and 100% of the subject's 6-RM for knee extensions. In the moderate-intensity
protocol, the load was 70% of the high-intensity protocol, and both protocols lasted 90 min. The contractile properties of
the leg extensor muscles were tested using isokinetic knee extensions, electrical stimulation, and squat jumps. Tests were
done before exercise, 5–20 min after exercise, and frequently for 33 h after exercise. The decrements in knee extension performance
were greater after the high-intensity protocol (12–14%), as compared to the moderate-intensity protocol (6–7%, P < 0.01). Similar decrements were seen in squat-jumping performance after the high-intensity protocol. Decrements in electrically
evoked force were also greatest after the high-intensity protocol (P < 0.05), and were more pronounced at 20 Hz stimulation than at 50 Hz stimulation (P < 0.05). The recovery of performance showed a biphasic pattern, with a rapid recovery within the first 11 h after exercise,
followed by a leveling off or a second drop in performance 11–22 h after exercise. All variables were back to baseline by
3 h after the moderate-intensity protocol, while all variables were back to baseline by 33 h after the 100% protocol. The
role of structural changes (excitation-contraction coupling and contractile proteins) in the long-lasting performance decrements
seen after the high-intensity protocol is discussed.
Accepted: 14 February 2000 |
| |
Keywords: | Strength exercise Fatigue Recovery Urea Creatine kinase |
本文献已被 PubMed SpringerLink 等数据库收录! |
|