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1.
P. AAGAARD E. B. SIMONSEN M. TROLLE J. BANGSBO K. KLAUSEN 《Acta physiologica (Oxford, England)》1996,156(2):123-129
The present study investigated the effects of three different strength training regimes on the isokinetic strength profile of the knee extensors (quadriceps, Q) and flexors (hamstrings, H) and if increases in isokinetic strength were accompanied by an enhanced performance during a more complex leg movement, the soccer kick. Twenty-two elite soccer players performed 12 weeks of strength training (three times per week) at either high resistance (HR group: 4 sets, 8 reps, 8RM loading), low resistance (LR group: 4 sets, 24 reps, 24RM loading), loaded kicking movements (LK group: 4 sets, 16 reps, 16RM loading) while one group served as controls (CO group). Isokinetic concentric and eccentric moment of force was obtained (KinCom) as peak moment (Mpeak) and moment at 50° knee flexion (M50) at angular velocities of 30, 120, 240° s-1. Isokinetic knee joint strength was unchanged in groups LR, LK, CO. However, after the HR strength training, concentric Mpeak (±SD) increased (P<0.01) at 30° s-1 (Q, 258±37 to 297±57 Nm; H, 122±22 to 140±21 Nm). Furthermore, eccentric Mpeak increased at 30, 120 and 240° s-1 (Q, 274±60 to 345±57 Nm (P<0.01), 291±56 to 309±49 Nm and 275±43 to 293±36 Nm (P<0.05), respectively; H, 143±32 to 158±25 Nm, 152±39 to 169±31 Nm and 148±27 to 163±19 Nm (P<0.05)). Corresponding increases (P<0.05) were observed for M50. The H/Q ratio calculated as eccentric hamstring strength divided by concentric quadriceps strength (Hecc/Qcon, representative for knee extension) at 240° s-1 increased (P<0.05) from 107 to 118% (based on Mpeak) and from 90 to 105% (M50). Kicking performance estimated by maximal ball flight velocity was unaffected by any of the strength training regimes investigated. In conclusion, only heavy-resistance strength training induced increases in isokinetic muscle strength in the absence of learning effects. Concentric strength gains were observed at the actual velocity of training, while eccentric strength gains were found over the entire range of velocities examined. The capacity of the hamstring muscles for providing stability to the knee joint during fast extension was augmented as a result of the heavy-resistance strength training. Strength training should be integrated with other types of training involving the actual movement pattern in order to increase the performance within more complex movement patterns. 相似文献
2.
Summary Six healthy women (21.8±0.4 y) did isometric strength training of the left plantarflexors at an ankle joint angle of 90°. Training sessions, done 3 times per week for 6 weeks, consisted of 2 sets of ten 5 s maximal voluntary contractions. Prior to and following the training, and in random order, voluntary and evoked isometric contraction strength was measured at the training angle and at additional angles: 5°, 10°, 15°, and 20° intervals in the plantarflexion and dorsiflexion directions. Evoked contraction strength was measured as the peak torque of maximal twitch contractions of triceps surae. Training increased voluntary strength at the training angle and the two adjacent angles only (p<0.05). Time to peak twitch torque was not affected by training. Twitch half relaxation time increased after training (p=0.013), but the increase was not specific to the training angle. There was a small (1.1%, p<0.05) increase in calf circumference after training. Evoked twitch torque did not increase significantly at any joint angle. It was therefore concluded that a neural mechanism is responsible for the specificity of joint angle observed in isometric training. 相似文献
3.
Effects of equivolume isometric training programs comprising medium or high resistance on muscle size and strength 总被引:1,自引:0,他引:1
Kanehisa H Nagareda H Kawakami Y Akima H Masani K Kouzaki M Fukunaga T 《European journal of applied physiology》2002,87(2):112-119
Isometric unilateral elbow extension training was conducted for 10 weeks (3 times per week) on 12 young adult men to investigate
the effects of equivolume exercise programs with different combinations of intensity and duration on the morphological and
functional aspects of the triceps brachii muscle. One group of 6 subjects trained by developing maximal voluntary contraction
(MVC) for 6 s per set with 12 sets per session (100%G), while the other group of 6 subjects trained at 60% of MVC for 30 s
per set with 4 sets per session (60%G). Training significantly increased the muscle volume (V
m), fascicle pennation angle of the triceps brachii, and torque output during concentric and eccentric elbow extensions at
three constant velocities of 0.52, 1.57, and 3.14 rad·s–1 as well as under the training condition, with no significant differences in the relative gains between the two programs.
However, 100%G showed significantly greater V
m than 60%G after training, when V
m before training was normalized. Thus, only 60%G significantly increased the ratio of torque to V
m developed in the eccentric actions at the three velocities and concentric action at 1.57 rad·s–1. The present results indicate that isometric training programs of medium resistance/long duration and high resistance/short
duration produce different effects on V
m and dynamic strength relative to V
m, even if the training volume is equalized between the two protocols.
Electronic Publication 相似文献
4.
John L. Ewing Jr. D. Roy Wolfe Marc A. Rogers Mark L. Amundson G. Alan Stull 《European journal of applied physiology》1990,61(1-2):159-162
Summary Twenty young men trained the right knee extensors and flexors on an isokinetic dynamometer three times weekly over a 10-week period. During each session, 10 men in the slow training group completed three sets of 8 maximal contractions at a rate of 1.05 rad s–1, whereas the other 10, the fast group, completed three sets of 20 contractions at a rate of 4.19 rad s–1. Subjects were pre- and post-tested for peak torque and power on an isokinetic dynamometer at 1.05, 3.14, and 4.19 rad s–1. Proportions of muscle fibre-types and fibre cross-sectional areas were determined from biopsy specimens taken before and after training from the right vastus lateralis. When testing was conducted at 1.05 rad s–1, the slow group improved (P<0.05) peak torque by 24.5 N m (8.5%), but no change was noted for the fast group. Power increased (P< 0.05) by 32.7 W (13.6%) in the slow group and 5.5 W (2.5%) in the fast. At 3.14 rad s–1, both groups increased (P<0.05) peak torque and power. At 4.19 rad s–1, the fast group increased (P<0.05) peak torque by 30.0 N m (19.7%), whereas no training effect was observed in the slow group. There was no significant change in power in either group at 4.19 rad s–1, No significant changes were observed over the 10-week training period in percentages of type I, IIa and IIb fibres, but both groups showed significant increases (P<0.05) in type I and IIa fibre areas. No differences were noted between groups, and no hypertrophy of type IIb fibres was observed. 相似文献
5.
The purpose was to investigate if shoulder muscle strength in post-rehabilitated persons with spinal cord injury (SCI) was affected by kayak ergometer training and to compare shoulder strength in persons with SCI and able-bodied persons. Ten persons with SCI (7 males and 3 females, injury levels T3–T12) performed 60 min kayak ergometer training three times a week for 10 weeks with progressively increased intensity. Maximal voluntary concentric contractions were performed during six shoulder movements: flexion and extension (range of motion 65°), abduction and adduction (65°), and external and internal rotation (60°), with an angular velocity of 30° s−1. Position specific strength was assessed at three shoulder angles (at the beginning, middle and end of the range of motion) in the respective movements. Test–retests were performed for all measurements before the training and the mean intraclass correlation coefficient was 0.941 (95% CI 0.928–0.954). There was a main effect of kayak ergometer training with increased shoulder muscle strength after training in persons with SCI. The improvements were independent of shoulder movement, and occurred in the beginning and middle positions. A tendency towards lower shoulder muscle strength was observed in the SCI group compared to a matched reference group of able-bodied persons. Thus, it appears that post-rehabilitated persons with SCI have not managed to fully regain/maintain their shoulder muscle strength on a similar level as that of able-bodied persons, and are able to improve their shoulder muscle strength after a period of kayak ergometer training. 相似文献
6.
James J. Hoffmann Steven F. Loy Brian I. Shapiro George J. Holland William J. Vincent Stephen Shaw Deborah L. Thompson 《European journal of applied physiology》1993,67(1):43-47
Summary This study compared the effects of 9 weeks of run (RT) versus cycle (CT) training on ventilatory threshold (Thv) determined during treadmill (TM) and cycle ergometer (CE) graded exercise testing. Sixteen college age men were assigned to a RT or CT group and performed a TM and a CE test before and after training. Both training groups performed similar training protocols which initially consisted of continuous exercise 4 days·week–1 at 75–80% maximum heart rate (fc,max) for 45 min. Training intensity was later increased to 80–85% fc
max and interval training (90–95% fc,max) was incorporated 2 days·week–1 into the continuous training. Both groups showed significantly improved maximal oxygen consumption (
O2max) on both TM and CE tests (P<0.01) with no significant differences between the groups. Significant Thv increases (P<0.05) were found on TM tests for RT (n=8) and CT (n=8) groups [mean (SD); 443 (438) and 373 (568) ml O2·min–1, respectively] with no difference between the groups. Results from the CE tests revealed a significant Thv increase (P<0.01) for the CT group [566 (663) ml O2·min–1] with no change for the RT group. The Thv improvement noted for the RT group was significantly different (P< 0.05) comparing CE with TM tests but not for the CT group. The results indicate that CT and RT improvement in Thv for runners is dependent upon mode of training and testing, and there is an apparent dissociation of
O2maxand Thv specific to training. 相似文献
7.
Summary This study investigated whether isokinetic strength training might induce changes in static and dynamic power already achieved as a result of isometric strength training. The subjects were twelve males. The isometric strength and dynamic power of elbow flexors were tested by means of an electric dynamometer and fly-wheel every two weeks. During the first 8 weeks all subjects trained the elbow flexors isometrically at four different positions of elbow joints. This training produced 27–36% gains in isometric strength and 34–46% in power. Thereafter the subjects were divided into two groups: the FG group who trained isokinetically at a fast velocity of 157·s–1, and the SG group at slow velocity of 73·s–1. After 6 weeks of training, the FG group produced a significant gain in power with light equivalent masses and the SG group did so with heavy equivalent masses. Neither group showed change in isometric strength. 相似文献
8.
Serum hormones in male strength athletes during intensive short term strength training 总被引:1,自引:0,他引:1
Summary Training-induced adaptations in the endocrine system and strength development were investigated in nine male strength athletes during two separate 3-week intensive strength training periods. The overall amount of training in the periods was maintained at the same level. In both cases the training in the first 2 weeks was very intensive: this was followed by a 3rd week when the overall amount of training was greatly decreased. The two training periods differed only in that training period I included one daily session, while during the first 2 weeks of period II the same amount of training was divided between two daily sessions. In general, only slight and statistically insignificant changes occurred during training period I in mean concentrations of serum hormones examined or sex hormone-binding globulin as well as in maximal isometric leg extensor force. However, during training period II after 2 weeks of intensive strength training a significant decrease (P<0.05) was observed in serum free testosterone concentration [from 98.4 (SD 24.5) to 83.8 (SD 14.7) pmol · l–1] during the subsequent week of reduced training. No change in the concentration of total testosterone was observed. This training phase was also accompanied by significant increases (P<0.05) in serum luteinizing hormone (LH) and cortisol concentrations. After 2 successive days of rest serum free testosterone and LH returned to (P<0.05) their basal concentrations. Training period II led also to a significant increase (P<0.05) [from 3942 (SD 767) to 4151 (SD 926) N] in maximal force. These findings suggest that in male strength athletes dividing the amount of training into smaller units may create more effective training stimuli leading to further strength development. 相似文献
9.
A. F. Mannion P. M. Jakeman P. L. T. Willan 《European journal of applied physiology》1992,65(4):370-375
Summary Isokinetic training of right and left quadriceps femoris was undertaken three times per week for 16 weeks. One group of subjects (n=13) trained at an angular velocity of 4.19 rad·s–1 and a second group (n=10) at 1.05 rad·s–1. A control group (n=10) performed no training. Maximal voluntary contraction (MVC) of the quadriceps, and peak pedal velocity (p,peak) and peak power output (W
peak) during all-out cycling (against loads equivalent to 9, 10, 11, 12, 13 and 14% MVC) were assessed before and after training. The two training groups did not differ significantly from each other in their training response to any of the performance variables (P>0.05). No significant difference in MVC was observed for any group after the 16-week period (P=0.167). The post-training increases in averageW
peak (7%) and p,peak (6%) during the cycle tests were each significantly different from the control group response (P=0.018 andP=0.008, respectively). It is concluded that 16 weeks of isokinetic strength training of the knee extensors is able to significantly improve p,peak andW
peak during sprint cycling, an activity which demands considerable involvement of the trained muscle group but with its own distinct pattern of coordination. 相似文献
10.
Adaptation to chronic eccentric exercise in humans: the influence of contraction velocity 总被引:1,自引:0,他引:1
Paddon-Jones D Leveritt M Lonergan A Abernethy P 《European journal of applied physiology》2001,85(5):466-471
We compared changes in muscle fibre composition and muscle strength indices following a 10 week isokinetic resistance training
programme consisting of fast (3.14 rad.s–1) or slow (0.52 rad.s–1) velocity eccentric muscle contractions. A group of 20 non-resistance trained subjects were assigned to a FAST (n=7), SLOW (n=6) or non-training CONTROL (n=7) group. A unilateral training protocol targeted the elbow flexor muscle group and consisted of 24 maximal eccentric isokinetic
contractions (four sets of six repetitions) performed three times a week for 10 weeks. Muscle biopsy samples were obtained
from the belly of the biceps brachii. Isometric torque and concentric and eccentric torque at 0.52 and 3.14 rad.s–1 were examined at 0, 5 and 10 weeks. After 10 weeks, the FAST group demonstrated significant [mean (SEM)] increases in eccentric
[29.6 (6.4)%] and concentric torque [27.4 (7.3)%] at 3.14 rad.s–1, isometric torque [21.3 (4.3)%] and eccentric torque [25.2 (7.2)%] at 0.52 rad.s–1. The percentage of type I fibres in the FAST group decreased from [53.8 (6.6)% to 39.1 (4.4)%] while type IIb fibre percentage
increased from [5.8 (1.9)% to 12.9 (3.3)%; P<0.05]. In contrast, the SLOW group did not experience significant changes in muscle fibre type or muscle torque. We conclude
that neuromuscular adaptations to eccentric training stimuli may be influenced by differences in the ability to cope with
chronic exposure to relatively fast and slow eccentric contraction velocities. Possible mechanisms include greater cumulative
damage to contractile tissues or stress induced by slow eccentric muscle contractions.
Electronic Publication 相似文献
11.
Spurway NC Watson H McMillan K Connolly G 《European journal of applied physiology》2000,82(5-6):374-380
Ten male and ten female young adults trained the knee extensors of one leg eccentrically and those of the other concentrically
for 6 weeks, using a gymnasium leg-extension machine. Before and after training, both legs of each subject were tested isometrically
for maximum voluntary knee-extensor force, and in both eccentric and concentric isokinetic modes at 30–250° · s−1. All limbs showed improvements in mean eccentric force (ranging from 18% in the concentrically trained legs of the females
to 31% in the eccentrically trained legs of the males, P < 0.01–0.001). Upward trends in isometric and concentric forces were smaller and less- or non-significant. In three of the
four groups, mean eccentric forces after training were significantly greater than mean isometric forces, a difference that
was not evident before training. Ten further subjects of each gender, not trained but tested isometrically and isokinetically
three times in 2 weeks, showed no significant improvement over the series of tests. The explanation suggested is that the
increased percentage activation (“decreased inhibition”), often regarded as the main mechanism of strength gain in the early
weeks of training, had been displayed particularly in the subjects' eccentric performance. This implies that the activation-shortfall,
which is reduced by the initial phase of strength training, is largely or completely the same as that responsible for the
fact that untrained, voluntary eccentric force is less than that of isolated muscle.
Accepted: 18 February 2000 相似文献
12.
13.
Kuruganti U Parker P Rickards J Tingley M Sexsmith J 《European journal of applied physiology》2005,94(1-2):175-179
The bilateral limb deficit (BLD) describes the difference in maximal or near-maximal force generating capacity of muscles when they are contracted alone and in combination with the contralateral muscles. This study examined the effects of a 6-week (three times per week) bilateral leg strength training programme on BLD in younger and older adults. Data were collected from 33 subjects during slow (45°/s) isokinetic knee extensions and flexions before and after the training programme. After training, the BLD was reduced for extension (73.3–86.9%; P<0.001) but not for flexion (67.5–71.2%; P=0.13) regardless of age and gender. This study suggests that difficulty in recruiting all muscle units during a task involving bilateral activation can be improved by training, although such an effect appears to depend on the muscle group appreciated. 相似文献
14.
Summary Thirty young male adults matched in two experimental groups (n=12) and a control group (n=6) were investigated before and after an 8-week strength training period. Group A trained with few repetitions and maximal loads, whereas group B had more repetitions with smaller loads. Both groups lifted the same total load during each training period, four times a week. Maximal voluntary strength (MVS) of a shot-put arm movement, muscular excitability and contractile properties (time to peak of contraction with threshold stimuli, half relaxation time) were measured in M. deltoideus and M. triceps brachii, C. longum, for two durations of stimulation. Increases of 14.8% (group A) and 12.2% (group B) in MVS were observed. Muscle excitability significantly increased in all types of training and both muscles. Significant shortening of the contraction time, dependent on the type of training, was observed in both studied muscles. It appears that the strength training in group A involved the fast fibers of both muscles, whereas in group B the training influence was less marked, and affected both fast and slow fiber types. 相似文献
15.
踝关节等速肌力训练对老年脑卒中患者平衡功能的影响 总被引:1,自引:0,他引:1
目的 探讨应用等速肌力训练加强踝关节屈伸肌群的肌力,对老年脑卒中患者平衡功能的影响。 方法 选取40例老年脑卒中患者随机分为对照组(n=20)、治疗组(n=20),对照组接受常规康复治疗,治疗组在对照组基础上,增加针对踝关节背伸与跖屈肌群的等速肌力训练。2组患者治疗前和治疗3周后均进行Berg平衡量表(Berg balance scale, BBS);“起立-走”计时测试(Timed up and go test, TUGT);以及ProKin平衡仪的评估,参数包括Y-COP标准差、运动轨迹长度、运动轨迹面积、踝关节背伸与跖屈肌群的等速峰力矩等平衡功能相关指标的测量。 结果 2组患者经过平衡训练后,平衡功能的各项指标均较治疗前有改善(P<0.05);治疗组患者治疗后平衡功能与对照组比较,各项评估指标均优于对照组(P<0.05)。 结论 踝关节等速肌力训练,可以明显改善老年脑卒中患者踝关节背伸与跖屈肌群的肌力及平衡功能。 相似文献
16.
We evaluated the effects of different training frequencies on arterial stiffness. 77 elderly women (mean 68.8 years and 7.0
SD) were divided into two training (1DW and 2DW) and a CONTROL group (n = 23). 1DW (n = 29) participated in 90-min group training once a week for 12 weeks, while 2DW (n = 25) attended twice a week. Each training program included recreational activities, six to eight resistance exercises for
circuit training, and leg exercises for chair-based exercise. Brachial systolic and diastolic blood pressures and the brachial-to-ankle
pulse-wave velocity (baPWV) were obtained in the supine position. Muscle strength and ventilatory threshold were also measured.
After the training program, a reduction (P < 0.01) in baPWV was observed in 2DW (−7.8 ± 7.0%) but not in 1DW (−1.5 ± 7.5%) and CONTROL (−0.4 ± 7.5%) without any changes
in other measurements. The results suggest that, in order to improve arterial stiffness, an exercise frequency of at least
twice a week is to be recommended for elderly. 相似文献
17.
Brian R. MacIntosh Walter Herzog Esther Suter J. Preston Wiley Jason Sokolosky 《European journal of applied physiology》1993,67(6):499-506
It has been reported that there is a relationship between power output and fibre type distribution in mixed muscle. The strength of this relationship is greater in the range of 3–8 rad · s–1 during knee extension compared to slower or faster angular knee extensor speeds. A mathematical model of the force: velocity properties of muscle with various combinations of fast- and slow-twitch fibres may provide insight into why specific velocities may give better predictions of fibre type distribution. In this paper, a mathematical model of the force: velocity relationship for mixed muscle is presented. This model demonstrates that peak power and optimal velocity should be predictive of fibre distribution and that the greatest fibre type discrimination in human knee extensor muscles should occur with measurement of power output at an angular velocity just greater than 7 rad · s–1. Measurements of torque: angular velocity relationships for knee extension on an isokinetic dynamometer and fibre type distribution in biopsies of vastus lateralis muscles were made on 31 subjects. Peak power and optimal velocity were determined in three ways: (1) direct measurement, (2) linear regression, and (3) fitting to the Hill equation. Estimation of peak power and optimal velocity using the Hill equation gave the best correlation with fibre type distribution (r > 0.5 for peak power or optimal velocity and percentage of fast-twitch fibres). The results of this study confirm that prediction of fibre type distribution is facilitated by measurement of peak power at optimal velocity and that fitting of the data to the Hill equation is a suitable method for evaluation of these parameters. 相似文献
18.
Muscle strength and, to a greater extent, power inexorably decline with ageing. Quantitative loss of muscle mass, referred to as sarcopenia, is the most important factor underlying this phenomenon. However, qualitative changes of muscle fibres and tendons, such as selective atrophy of fast-twitch fibres and reduced tendon stiffness, and neural changes, such as lower activation of the agonist muscles and higher coactivation of the antagonist muscles, also account for the age-related decline in muscle function. The selective atrophy of fast-twitch fibres has been ascribed to the progressive loss of motoneurons in the spinal cord with initial denervation of fast-twitch fibres, which is often accompanied by reinnervation of these fibres by axonal sprouting from adjacent slow-twitch motor units (MUs). In addition, single fibres of older muscles containing myosin heavy chains of both type I and II show lower tension and shortening velocity with respect to the fibres of young muscles. Changes in central activation capacity are still controversial. At the peripheral level, the rate of decline in parameters of the surface-electromyogram power spectrum and in the action-potential conduction velocity has been shown to be lower in older muscle. Therefore, the older muscle seems to be more resistant to isometric fatigue (fatigue-paradox), which can be ascribed to the selective atrophy of fast-twitch fibres, slowing in the contractile properties and lower MU firing rates. Finally, specific training programmes can dramatically improve the muscle strength, power and functional abilities of older individuals, which will be examined in the second part of this review. 相似文献
19.
Interference of strength development by simultaneously training for strength and endurance 总被引:4,自引:0,他引:4
Robert C. Hickson 《European journal of applied physiology》1980,45(2-3):255-263
Summary The purpose of this study was to determine how individuals adapt to a combination of strength and endurance training as compared to the adaptations produced by either strength or endurance training separately. There were three exercise groups: a strength group (S) that exercised 30–40 min·day–1, 5 days·week–1, an endurance group (E) that exercised 40 min·day–1, 6 days·week–1; and an S and E group that performed the same daily exercise regimens as the S and E groups. After 10 weeks of training, VO2 max increased approx. 25% when measured during bicycle exercise and 20% when measured during treadmill exercise in both E, and S and E groups. No increase in VO2 max was observed in the S group. There was a consistent rate of development of leg-strength by the S group throughout the training, whereas the E group did not show any appreciable gains in strength. The rate of strength improvement by the S and E group was similar to the S group for the first 7 weeks of training, but subsequently leveled off and declined during the 9th and 10th weeks. These findings demonstrate that simultaneously training for S and E will result in a reduced capacity to develop strength, but will not affect the magnitude of increase in VO2 max.This research was supported by a University of Illinois at Chicago Circle Research Board Grant and by a NIH Biomedical Research Support Grant (HEW RR07158-2) to the University of Illinois at Chicago Circle 相似文献
20.
Summary The purpose of this study was to evaluate metabolic and circulatory responses to interval training of legs or arms during steady-state, submaximal cycling. 15 college males cycled on a bicycle ergometer twice with arms (63 and 83 W) and twice with legs (100 and 125 W) before and following 5 weeks of daily interval training. Seven subjects trained with arm cycling and eight with leg cycling. Significant post-training decreases in submaximal oxygen consumption (
O2), heart rate (HR), and venous blood lactate (LAv) were noted when cycling with trained and untrained muscles with the magnitude of change significantly greater with trained muscles. These results indicate metabolic and circulatory adaptations to interval training that are mediated centrally and peripherally. With respect to HR, but not
O2, training a larger muscle mass (legs) produced a greater central but lesser peripheral effect whereas the opposite was true for the smaller arm muscles. The data also suggested that the peripheral adaptation involves a common mechanism controlling both HR and LAv changes with a separate mechanism controlling
O2.Supported by a grant from the Central Ohio Heart Chapter 相似文献