Effect of static and dynamic exercises on muscular strength and hypertrophy.
Explore the source record for details and available documents.
Exercise↗
SEARCH · PubMed Health
Results for “Strength exercises”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Longitudinal improvement of self-regulation through practice: building self-control strength through repeated exercise.
This study examined the results of repeated exercises of self-control in relation to self-regulatory strength over time. A sample of 69 U.S. college students spent 2 weeks doing 1 of 3 self-control exercises: monitoring and improving posture, regulating mood, or monitoring and recording eating. Compared with a no-exercise control group, the participants who performed the self-control exercises showed significant improvement in self-regulatory capacity as measured by quitting faster on a hand-grip exercise task following a thought-suppression exercise.
Adult↗
Exercise effect on strength and range of motion of hand intrinsic muscles and joints.
The intrinsic muscles of the hand are largely neglected in training, mainly because certain biomechanical principles must be applied in order for these muscles to be involved in hand exercises. Following these principles, a system of stretching and isometric exercises was developed. Twelve men exercised for four weeks, three times daily. Significant improvement in seven out of the 12 strength measurements was noted. Exercise seemed to affect just the metacarpophalangeal joints range of motion, while distal and proximal interphalangeal joints remained largely unaffected.
Finger Joint↗
Site specificity of regular health club exercise on muscle strength, fitness, and bone density in women aged 29 to 45 years.
OBJECTIVE: To determine the effect of regular exercise with use of stepper or skier machines on muscle strength, cardiovascular fitness, bone mineral density, and markers of bone turnover in women aged 29 to 45 years. SUBJECTS AND METHODS: We evaluated 14 women: 5 who used a stepper machine for at least 3 hours each week for 2 years, 4 who used a skier machine for at least 3 hours each week for 2 years, and 5 who did not exercise (controls). All women were healthy, had no history of disease or medication use known to affect bone metabolism, and had normal levels of estradiol-17beta. Differences between the exercise and control groups were analyzed with the Kruskal-Wallis test. RESULTS: No significant differences were noted between the exercise groups and the control group with respect to age, height, total body bone mineral density, calcium intake, and metabolic bone markers. Significant differences were noted between the groups in body weight (stepper vs control, P=.03; skier vs control, P=.02), body mass index (stepper vs control, P=.03; skier vs control, P=.02), Physical Activity Score (stepper vs control, P=.009; skier vs control, P=.01), percentage body fat (stepper vs control, P=.03; skier vs control, P=.02), and maximum oxygen consumption (stepper vs control, P=.009; skier vs control, P=.009). Bilateral hip extensor strength was significantly stronger in the stepper group than in the skier group (P=.03). Grip strength was significantly stronger in the stepper group than in the skier group (right, P=.01; left, P=.049). CONCLUSION: Although comparable health club exercises can contribute to fitness, their site-specific effect varies. Stepper machines are preferred over skier machines for improving hip extensor strength.
Adult↗
Effects of long term Tai Chi practice and jogging exercise on muscle strength and endurance in older people.
OBJECTIVES: To investigate the influence of regular Tai Chi (TC) practice and jogging on muscle strength and endurance in the lower extremities of older people. METHODS: Twenty one long term older TC practitioners were compared with 18 regular older joggers and 22 sedentary counterparts. Maximum concentric strength of knee flexors and extensors was tested at angular velocities of 30 degrees/s and 120 degrees/s. Ankle dorsiflexors and plantar flexors were tested at 30 degrees/s and the dynamic endurance of the knee flexors and extensors was assessed at a speed of 180 degrees/s. RESULTS: The differences in the muscle strength of the knee joint amongst the three experimental groups were significant at the higher velocity. The strengths of knee extensors and flexors in the control group were significantly lower than those in the jogging group and marginally lower than those in the TC group. For the ankle joint, the subjects in both the TC and jogging groups generated more torque in their ankle dorsiflexors. In addition, the muscle endurance of knee extensors was more pronounced in TC practitioners than in controls. CONCLUSION: Regular older TC practitioners and joggers showed better scores than the sedentary controls on most muscle strength and endurance measures. However, the magnitude of the exercise effects on muscles might depend on the characteristics of different types of exercise.
Age Factors↗
The impact of a repeated bout of eccentric exercise on muscular strength, muscle soreness and creatine kinase.
The purpose of this study was to determine if there were any beneficial or detrimental effects regarding delayed onset muscle soreness (DOMS), serum creatine kinase (CK), and maximum concentric strength at 80% of 1-RMconc, if a bout of eccentric exercise was repeated at 48 h after an initial bout. A secondary purpose was to determine whether unaccustomed eccentrics might affect plasma cholesterol (TC). Twenty-six men were randomly assigned to a control (Group 1) or experimental group (Group 2). Both groups performed three sets (12 repetitions per set) of the eccentric phase of a chest press, at 80% of one repetition maximum (1-RMconc); Group 2 repeated this exercise 48 h later. DOMS and CK were measured before, and every 24 h for 8 days after; TC was measured before, and every 24 h for 4 days. Maximum strength during the concentric phase of a chest press (1-RMconc) was measured before and at 48-h intervals after. A repeated measures analysis of variance revealed a significant time effect (P < 0.05) for DOMS, CK and strength, but no significant difference between groups (P < 0.05). An interesting finding was the significant (P < 0.05) reduction in TC at 24, 48 and 72 h, after exercise in both groups, which we hypothesized was associated with cellular repair. From these results we concluded that when a bout of eccentrics is repeated 48 h after an initial bout, there is no change in the characteristic time-course and/or intensity of DOMS, CK or 1-RMconc.
Adult↗
"Task-oriented" exercise improves hamstring strength and spastic reflexes in chronic stroke patients.
BACKGROUND AND PURPOSE: Despite the belief that after cerebral infarction only limited functional gains are possible beyond the subacute period, we tested the hypothesis that a 12-week program of "task-oriented" treadmill exercise would increase muscle strength and decrease spastic reflexes in chronic hemiparetic patients. METHODS: Fourteen subjects, aged 66+/-3 (mean+/-SEM) years, with residual gait deviations due to remote stroke (>6 months), underwent repeated measures of reflexive and volitional (concentric and eccentric) torque with use of isokinetic dynamometry on the hamstring musculature bilaterally. Torque output was measured at 4 angular velocities (30(o), 60(o), 90(o), and 120(o)/s). RESULTS: After 3 months of 3 times/wk low-intensity aerobic exercise, there were significant main effects (2 legs [P<0.01]x2 times [P<0. 01]x4 angular velocities [P<0.05]) for concentric torque production. Torque/time production in the concentric mode also improved significantly in the paretic (50%, P<0.01) and nonparetic hamstrings (31%, P<0.01). Eccentric torque/time production increased by 21% (P<0.01) and 22% (P<0.01) in the paretic and nonparetic hamstrings, respectively. Passive (reflexive) torque/time generation in the paretic hamstrings decreased by 11% (P<0.027). Reflexive torque/time was unchanged in the nonparetic hamstrings (P=0.45). CONCLUSIONS: These findings provide evidence that progressive treadmill aerobic exercise training improves volitional torque and torque/time generation and reduces reflexive torque/time production in the hemiparetic limb. Strength changes associated with improved functional mobility in chronic hemiparetic stroke survivors after treadmill training will be reported in future articles.
Aged↗
Effects of microcurrent treatment on perceived pain and muscle strength following eccentric exercise.
OBJECTIVE: The purpose of this study was to assess the effect of low-volt, microamperage stimulation (LVMAS) on perceived pain and muscle strength following an intense bout of eccentric exercise. DESIGN AND SETTING: An experimental pretest-posttest control group design was used for the study. The experiment was conducted in the Lower Extremity Research Laboratory at Georgia State University. SUBJECTS: Twelve females and six males (mean age 27 +/- 5 yr). MEASUREMENTS: Subjects, randomly assigned to experimental (EXP, n = 6), sham (SHAM, n = 6), and control (CON, n = 6) groups, were tested before, and at 24, 48, and 72 hours following, an intense bout of eccentric exercise. RESULTS: Three two-way (group x time) analyses of variance (ANOVAs) with repeated measures on the last factor were used to analyze the data. A significant time main effect was identified. Results indicated that perceived pain was not reduced in the EXP group as compared with the SHAM and CON groups. Muscle strength in the EXP group did not return to the initial baseline measure more rapidly than in the SHAM and CON groups. CONCLUSIONS: We conclude that the use of LVMAS alone is not effective in reducing pain and increasing muscle function following an exhaustive bout of eccentric exercise.
Journal Article↗
Isokinetic muscle strength predicts maximum exercise tolerance in renal patients on chronic hemodialysis.
Patients with end-stage renal disease receiving chronic hemodialysis have impaired exercise tolerance. To distinguish between a central cardiorespiratory and a peripheral skeletal muscular origin for this fatigue, we measured exercise performance and peak oxygen consumption during a maximum exercise test in 10 patients receiving chronic hemodialysis. Skeletal muscle function was measured with an isokinetic cycle ergometer and a Cybex II isokinetic dynamometer. Peak rates of oxygen consumption (17.7 +/- 3.6 [mean +/- SD] mL O2/kg/min), blood lactate concentrations (3.4 +/- 0.9 mmol/L), peak heart rates (168 +/- 12 beats/min), and rates of ventilation (37.3 +/- 14.6 L/min) were low, but respiratory exchange ratios (1.1 +/- 0.1) were compatible with maximal effort. There was a significant correlation between isokinetic muscle strength and VO2 peak, exercise duration, peak ventilation, and peak blood lactate concentrations (P less than 0.05 to less than 0.001), but not between hemoglobin concentration, total blood hemoglobin content, or hematocrit and these variables. Therefore, in renal dialysis patients, isokinetic muscle strength is a better predictor of exercise capacity than are variables determining blood oxygen carrying capacity. This suggests that altered skeletal muscle function explains the impaired exercise tolerance of anemic patients with end-stage renal disease receiving chronic hemodialysis.
Adult↗
Thigh-muscles strength training, dance exercise, dynamometry, and anthropometry in professional ballerinas.
The purpose of the present study was to assess the effects of 12 weeks of quadriceps and hamstring strength training on torque levels after a dance exercise and on selected anthropometric parameters. The sample consisted of 22 (ages, 25 +/- 1.3 years) full-time professional ballerinas who were randomly assigned into experimental (n = 12) and control (n = 10) groups. A dance routine designed to cause fatigue within 5 minutes, isokinetic dynamometry, and anthropometric assessments were conducted before and after strength training in both groups. Before strength training, the dance routine resulted in significant reductions of hamstring (p < 0.001) and quadriceps (p < 0.001) peak torques in both subject groups. However, after strength training, only control subjects demonstrated such torque decrements (p < 0.001) after the dance routine. Furthermore, the experimental group revealed greater knee extension (119 vs. 138 N.m; p < 0.001) and flexion (60 vs. 69 N.m; p < 0.001) torques, smaller sum of skinfolds (33.6 vs. 27.8 mm; p < 0.01), more fat-free mass (37.7 vs. 39.4 kg; p < 0.05), but unchanged body mass (p > 0.05) and thigh circumferences (p > 0.05). A negative relationship (p < 0.001) was found between initial strength levels and improvements measured at the end of the 12-week program. These results suggest that supplementary strength training for hamstring and quadriceps muscles is beneficial to professional ballerinas and their dancing; weaker individuals are more likely to benefit from such regimens than their stronger counterparts, whereas increases in thigh-muscle strength do not alter selected aesthetic components.
Adult↗
Comparison of changes in testosterone concentrations after strength and endurance exercise in well trained men.
Changes in the testosterone concentrations after single sessions of endurance and strength training were measured in seven well trained men, experienced in both forms of training. Both training sessions were rated as hard to very hard on the Borg scale. Blood samples for testosterone measurements were taken before, immediately after, and 2, 4 and 6 h after the training sessions as well as the next morning. The mean testosterone concentration increased 27% (P less than 0.02) and 37% (P less than 0.02) during the strength and endurance training session, respectively. Two hours after the training sessions the mean testosterone concentration had returned to the pre-training level and remained at that level for the length of the observation period. There were no significant differences in the changes in testosterone concentration after strength and endurance training but there were large differences in the testosterone response at the level of the individual. A high correlation (r = 0.98; P less than 0.001) for individuals was found between increases in testosterone concentration after strength and after endurance training. It was concluded that the changes in mean testosterone values followed the same timecourse after single sessions of strength and endurance training of the same duration and perceived exertion. The interindividual differences in testosterone response may be of importance for individual adaptation to training.
Adult↗
'Highstepping' exercise program promotes strength, self-esteem.
Explore the source record for details and available documents.
Aged↗
Myofibrillar disruption following acute concentric and eccentric resistance exercise in strength-trained men.
We have previously quantified the extent of myofibrillar disruption which occurs following an acute bout of resistance exercise in untrained men, however the response of well-trained subjects is not known. We therefore recruited six strength-trained men, who ceased training for 5 days and then performed 8 sets of 8 uni-lateral repetitions, using a load equivalent to 80% of their concentric (Con) 1-repetition maximum. One arm performed only Con actions by lifting the weight and the other arm performed only eccentric actions (Ecc) by lowering it. Needle biopsy samples were obtained from biceps brachii of each arm approximately 21 h following exercise, and at baseline (i.e., after 5 days without training), and subsequently analyzed using electron microscopy to quantify myofibrillar disruption. A greater (P < or = 0.05) proportion of disrupted fibres was found in the Ecc arm (45 +/- 11%) compared with baseline values (4 +/- 2%), whereas fibre disruption in the Con arm (27 +/- 4%) was not different (P > 0.05) from baseline values. The proportion of disrupted fibres and the magnitude of disruption (quantified by sarcomere counting) was considerably less severe than previously observed in untrained subjects after an identical exercise bout. Mixed muscle protein synthesis, assessed from approximately 21-29 h post-exercise, was not different between the Con- and Ecc-exercised arms. We conclude that the Ecc phase of resistance exercise is most disruptive to skeletal muscle and that training attenuates the severity of this effect. Moreover, it appears that fibre disruption induced by habitual weightlifting exercise is essentially repaired after 5 days of inactivity in trained men.
Adult↗
Effect of recombinant human growth hormone on the muscle strength response to resistance exercise in elderly men.
Normal aging is characterized by detrimental changes in body composition, muscle strength, and somatotropic function. Reduction in muscle strength contributes to frailty and risk for fracture in the elderly. Although older adults increase muscle strength as a result of resistance exercise training, the strength gains quickly level off, with only modest increases thereafter despite continued training. To investigate whether age-related deficits in the somatotropic axis limit the degree to which muscle strength can improve with resistance training in older individuals, we conducted a double blind, placebo-controlled exercise trial. Eighteen healthy elderly men (65-82 yr) initially underwent progressive weight training for 14 weeks to invoke a trained state. Subjects were then randomized to receive either 0.02 mg/kg BW.day recombinant human GH (rhGH) or placebo, given sc, while undertaking a further 10 weeks of strength training. Sequential measurements were made of muscle strength (one repetition maximum), body composition (dual energy x-ray absorptiometry), and circulating levels of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3. For each exercise, strength increased for both groups (P = 0.0001) through 14 weeks of training, with little improvement thereafter. Increases in muscle strength ranged from 24-62% depending on the muscle group. Baseline plasma IGF-I concentrations were similar in both groups (mean +/- SEM, 106 +/- 9 micrograms/L), approximately half that observed in healthy young adults. In the rhGH group, IGF-I levels increased to 255 +/- 32 micrograms/L at week 15 and 218 +/- 21 micrograms/L at week 24 (P < 0.001). In the placebo group, IGF-I increased slightly to 119 +/- 6 micrograms/L at 24 weeks. IGF-binding protein-3 also increased in the rhGH group (P < 0.05). rhGH had no effect on muscle strength at any time, and no systematic difference in muscle strength was observed between groups throughout the study. Body weight did not change in either group, but lean body mass increased, and fat mass decreased (P < 0.05) in the rhGH group. Supplementation with rhGH does not augment the response to strength training in elderly men. These results suggest that deficits in GH secretion do not underlie the time-dependent leveling off of muscle strength seen with training in the elderly and provide no support for the popular view of GH as an ergogenic aid.
Aged↗
What works. Exercising creativity: cardio, strength equipment is linked to patient records.
Explore the source record for details and available documents.
Exercise↗
The effect of low-intensity aerobic exercise on muscle strength, flexibility, and balance among sedentary elderly persons.
An experimental group of 20 elderly subjects participated in 8 weeks of low-intensity aerobic exercise while 27 subjects in a comparison group maintained their usual level of activity. The program consisted of stretching and strengthening chair exercises. A significant difference between the groups was found for flexibility of the ankles and the right knee. No significant difference was found between the groups for muscle strength or balance, although the experimental group improved their balance by 22%.
Accidental Falls↗
Severe exercise alters the strength and mechanisms of the muscle metaboreflex.
Previous studies have shown that in dogs performing mild to moderate treadmill exercise, partial graded reductions in hindlimb blood flow cause active skeletal muscle to become ischemic and metabolites to accumulate thus evoking the muscle metaboreflex. This leads to a substantial reflex increase in mean arterial pressure (MAP) mediated almost solely via a rise in cardiac output (CO). However, during severe exercise CO is likely near maximal and thus metaboreflex-mediated increases in MAP may be attenuated. We therefore evoked the metaboreflex via partial graded reductions in hindlimb blood flow in seven dogs during mild, moderate, and severe treadmill exercise. During mild and moderate exercise there was a large rise in CO (1.5 +/- 0.2 and 2.2 +/- 0.3 l/min, respectively), whereas during severe exercise no significant increase in CO occurred. The rise in CO caused a marked pressor response that was significantly attenuated during severe exercise (26.3 +/- 7.0, 33.2 +/- 5.6, and 12.2 +/- 4.8 mmHg, respectively). We conclude that during severe exercise the metaboreflex pressor response mechanisms are altered such that the ability of this reflex to increase CO is abolished, and reduced pressor response occurs only via peripheral vasoconstriction. This shift in mechanisms likely limits the effectiveness of the metaboreflex to increase blood flow to ischemic active skeletal muscle. Furthermore, because the metaboreflex is a flow-raising reflex and not a pressure-raising reflex, it may be most appropriate to describe the metaboreflex magnitude based on its ability to evoke a rise in CO and not a rise in MAP.
Animals↗
The benefits of strength training for older adults.
Aging is associated with a number of physiologic and functional declines that can contribute to increased disability, frailty, and falls. Contributing factors are the loss of muscle mass and strength as age increases, a phenomenon called sarcopenia. Sarcopenia can result or be exacerbated by certain chronic conditions, and can also increase the burden of chronic disease. Current research has demonstrated that strength-training exercises have the ability to combat weakness and frailty and their debilitating consequences. Done regularly (e.g., 2 to 3 days per week), these exercises build muscle strength and muscle mass and preserve bone density, independence, and vitality with age. In addition, strength training also has the ability to reduce the risk of osteoporosis and the signs and symptoms of numerous chronic diseases such as heart disease, arthritis, and type 2 diabetes, while also improving sleep and reducing depression. This paper reviews the current research on strength training and older adults, evaluating exercise protocols in a variety of populations. It is clear that a variety of strength-training prescriptions from highly controlled laboratory-based to minimally supervised home-based programs have the ability to elicit meaningful health benefits in older adults. The key challenges as this field of exercise science moves forward are to best identify the most appropriate strength-training recommendations for older adults and to greatly increase the access to safe and effective programs in a variety of settings.
Accidental Falls↗