In order to evaluate how mechanical power relates to athletic performance in weight lifting, specific movement power (SMP) was investigated using a newly developed dynamometer. Four simulated pull movements in weight lifting were measured: weight lifting pull (WL), second pull, back strength pull, and shoulder shrug pull. Subjects included 12 elite (EL) and 14 district (DI) level Japanese weight lifters. Athletic performance was defined as the highest total combined weight (snatch plus clean and jerk) lifted during competition. The highest SMP was observed in the WL. Force, velocity, and power relations were derived from the WL, showing higher velocity and power values in EL than DI at an identical force level. SMP in WL was found to be significantly correlated to athletic performance. SMP measured as a simulated pull movement in weight lifting employing the present dynamometer appears useful in evaluating athletic performance. Furthermore, this dynamometer provides force-velocity relationships during multiarticular explosive movements.
Kazuo Funato, Akifumi Matsuo, and Tetsuo Fukunaga
Thomas W. Balon, Jeffrey F. Horowitz, and Karen M. Fitzsimmons
Bodybuilders have used different carbohydrate loading regimens in conjunction with resistance exercise prior to competition in the belief that this would result in increased muscle size. To investigate this possibility, muscle girth measurements were obtained from nine weight-trained males before and after a control (standard isocaloric diet) and an experimental trial (carbohydrate loading). The latter regimen consisted of 3 days of intense weight-lifting while the subjects ingested a diet of 10% carbohydrate (CHO), 57% fat (F), and 33% protein (P), followed by 3 days of light weight-lifting and a day of rest while ingesting a diet of 80% CHO, 5% F, and 15% P. The control trial consisted of an identical weight-lifting regimen while subjects ingested an isocaloric (45 kcal/kg BWIday) diet. Body weight and girths (forearm, upper arm, chest, thigh, waist, and calf) were obtained before and after each trial in a relaxed and flexed state. The results indicated that an exercise/carbohydrate loading regimen had no significant effect on muscle girth as compared to the control trial. It is concluded that CHO loading has no additional advantage to enhancing muscle girth in bodybuilders over weight-lifting alone.
Timothy J. Suchomel and Christopher J. Sole
The force-production characteristics of 3 weight-lifting derivatives were examined by comparing the force–time curves of each exercise. Sixteen resistance-trained men performed repetitions of the hang power clean (HPC), jump shrug (JS), and hang high pull (HHP) on a force platform at several relative loads. Relative peak force (PFRel), relative impulse (IMPRel), peak rate of force development (PRFD), and time-normalized force–time curves of each exercise were compared. The JS produced greater PFRel than the HPC (P < .001, d = 1.38) and HHP (P < .001, d = 1.14), while there was no difference between the HPC and HHP (P = .338, d = 0.26). Similarly, the JS produced greater IMPRel than the HPC (P < .001, d = 0.52) and HHP (P = .019, d = 0.36). The HHP also produced greater IMPRel than the HPC (P = .040, d = 0.18). Finally, the JS produced greater PRFD than the HPC (P < .001, d = 0.73) and HHP (P = .001, d = 0.47), while there was no difference between the HPC and HHP (P = .192, d = 0.22). The HPC, JS, and HHP force–time profiles were similar during the first 75–80% of the movement; however, the JS produced markedly different force–time characteristics in the final 20–25% of the movement. The JS produced superior force-production characteristics, namely PFRel, IMPRel, and PRFD, as well as a unique force–time profile, compared with the HPC and HHP across several loads.
Christian Collet, Aymeric Guillot, Olivier Bolliet, and André Dittmar
To examine the preparation phase for the snatch lift in Olympic weight lifting. Two behavioral periods were studied, each corresponding to specific mental processes: a stance in front of the bar and placement of hands on the bar. Each period was hypothesized to elicit different responses of autonomic-nervous-system activity.
Twelve elite male subjects completed 12 lifts at 90% to 95% of their best grade after warm-up (80% of their best grade). Because peripheral autonomic-nervous-system activity is related to arousal and activation variation, 6 variables were continuously recorded: electrodermal (skin resistance and potential), thermovascular (skin temperature and skin blood flow), and cardiorespiratory (heart rate and respiratory frequency).
Responses (ie, phasic activities) were evident during the fi rst behavioral period. Decrease in heart rate (mean = 19 beats/min) or in respiratory frequency (mean = 8.6 beats/min) was related to attention processes. These responses were weaker (−0.16°C vs −0.25°C in skin temperature) and shorter (2.7 seconds vs 4.3 seconds in skin resistance) than those recorded during execution. The second phase showed variations in basal levels (mean increase in heart rate of 25%), related to increase in activation, thus attesting the muscle system’s process of preparation for effort.
Weight lifters separated the preparation phase into 2 stages that were closely matched by different physiological activities. Weight lifting requires participants to share their mental resources among the 2 demanding concentration phases by first focusing their attention on the execution and then mobilizing energizing resources.
Rick W. Wilson
Suprascapular nerve palsy has been frequently reported in athletes, particularly baseball pitchers, volleyball players, and weight lifters, but it is easily overlooked during the evaluation of shoulder pain. Entrapment of the suprascapular nerve is usually suspected only after atrophy is noted. The presence of painless weakness of the external rotator muscles should alert the clinician to the presence of nerve damage, which can be confirmed by electromyography. This case study demonstrates the usefulness of isokinetic testing and magnetic resonance imaging in identifying cystic lesions causing neuropathy among athletes who have failed conservative treatment for shoulder pain.
Karen L. Nau, Victor L. Katch, Robert H. Beekman, and Macdonald Dick II
Intraarterial blood pressure (BP) response to bench press weight lifting (WL) was evaluated in 11 children. Aortic systolic and diastolic pressures and heart rate (HR) were measured during WL. Baseline systolic and diastolic pressures were 120 and 81 mmHg, and HR was 86 bpm. Subjects lifted to voluntary fatigue weights equaling 60, 75, 90, and 100% of their predetermined one-repetition maximum (1RM). For each weight lifting condition, BP and HR increased as more repetitions were completed. Peak systolic pressure was 168, 177, 166, and 162 mmHg, peak diastolic pressure was 125, 139, 133, and 130 mmHg, and peak heart rate was 142, 148, 142, and 139 bpm at 60, 75, 90, and 100% 1RM, respectively. Peak BP and HR were greater during WL than rest but did not differ between conditions. The relative BP response to WL in children was similar to adult values. For all conditions, pressures increased as more repetitions were completed. It was concluded that peak pressures occur at voluntary fatigue, independent of the combination of resistance and repetitions used to achieve fatigue.
Frank C. Bakker, Marc S.J. Boschker, and Tjuling Chung
Investigating emotional imagery, Lang (1977, 1979) proposed a dichotomy between stimulus and response propositions. In this study, Lang’s model is applied to movement images of lifting of 4.5 and 9 kg weights. Twenty-two male and 17 female students participated in the study. During the imaginary lifting of the weights, the electromyographical activity (EMG) of both biceps brachii muscles were assessed. Imagery ability was measured with the Movement Imagery Questionnaire (MIQ) and another self-report rating scale. When response propositions were emphasized in the script, imaginary weight lifting resulted in greater muscle activity than when stimulus propositions were emphasized. During imagined lifting, EMG activity of the active arm was greater than that of the passive arm. In addition, in the active arm, a significant difference in EMG activity was found between 9 kg and 4.5 kg. It was concluded that Lang’s model is also applicable to emotionally neutral movement imagery.
Tadao Isaka, Junichi Okada, and Kazuo Funato
The purpose of this study was to describe the kinematic characteristics of the snatch technique from the viewpoint of barbell trajectory. Subjects included 6 elite male Asian weight lifters who participated in the first Japan International Friendship Tournament in 1993. Trajectories of the barbell during snatch lifts in the competition were video-taped. Three vertical acceleration peaks of the barbell during the pull movement were observed and corresponded to the first pull transition, and second pull phases. The angle of the resultant acceleration (ARA) of the barbell averaged 85° in the first pull and transition pull phases. In the second pull phase, the ARA was almost 140°, indicating that the barbell was accelerated anteriorly, away from the lifter. The results of this study suggest that during the first pull and transition pull phases, elite lifters pulled the barbell toward themselves to produce the needed vertical acceleration and that the resulting posterior movement of the barbell was controlled by the forward acceleration produced in the second pull phase.
W. Jack Rejeski, Karen M. Neal, Martine E. Wurst, Peter H. Brubaker, and Walter H. Ettinger Jr.
An elderly patient population was used to investigate whether an acute bout of aerobic exercise (AE) would reduce systolic blood pressure (SBP) to a greater extent than would a bout of weight lifting (WL). SBPs were studied in the context of a laboratory Stressor as well as during activities of daily living using ambulatory monitoring devices (AMBPs). Patients participated in a laboratory Stressor and were monitored via AMBP for 8 hr. SBPs were lower for up to 5 hr postexercise for the AE treatment only. In addition, in comparison to no-exercise control data, baseline SBP was lower for the AE group than the WL group prior to the Stressor. Subjects in the AE condition also tended to have lower SBP responses following exercise than patients in the WL group, although these differences did not reach a conventional level of statistical significance. These data provide evidence that single bouts of AE, but not WL, may lower SBP in elderly patients, even for those who have compromised function due to osteoarthritis of the knee.
Erika Zemková, Michal Jeleň, Zuzana Kovác̆iková, Gábor Ollé, Tomáš Vilman, and Dušan Hamar
The study evaluates the effect of weight lifted on power in the concentric phase of resistance exercises on stable and unstable surfaces. A group of 19 fit men performed randomly on different days 3 reps of (a) barbell chest presses on the bench and Swiss ball, and (b) barbell squats on stable base and BOSU ball. Exercises were performed without and with countermovement (CM) using maximal effort in concentric phase. Initial weight of 20 kg was increased by 10 kg or 5 kg (at higher loads) up to at least 85% of previously established 1RM under stable conditions. Results showed no significant differences in mean power in the concentric phase of stable and unstable CM chest presses at lower weights lifted (from 20 to 50 kg). However, its values were significantly higher during chest presses on the bench than on Swiss ball while lifting higher weights (from 60 to 90 kg). Similarly, mean power in the concentric phase of squats was significantly higher on stable base than on BOSU ball at higher weights lifted (from 60 to 90 kg). Though a set of data showed significant differences, the effect sizes ≤ 0.7 suggest no practically meaningful differences. It may be concluded that unstable base compromises the power in the concentric phase of resistance exercises, however, only at higher weights lifted.