Safety Of Resistance Exercise Research Articles

Cardiac Responses to Prenatal Resistance Exercise with and without the Valsalva Maneuver.

Exercise guidelines recommend incorporating resistance exercise (RE) into a regular aerobic training program during pregnancy. However, few women do so because of uncertainties about the safety of prenatal RE, particularly regarding the Valsalva maneuver (VM). The aim of this study was to determine the acute cardiovascular responses to prenatal RE at different intensities, with and without VM. Healthy pregnant (n = 15; 22.9 ± 5.9 wk of gestation) and nonpregnant women (n = 15) were recruited. Maximal strength over 10 repetitions (10RM) for semireclined leg press was determined. Women underwent standardized assessments of cardiac structure, function and mechanics (echocardiography), heart rate (ECG), and blood pressure (photoplethysmography) at baseline, during RE at 20%, 40%, and 60% 10RM while free-breathing, and at 40% 10RM with VM. Significant differences were identified between subjects at baseline (independent t-tests), between and within subjects during free-breathing RE (general linear model, baseline as a covariate), and between and within subjects for 40% 10RM free-breathing versus VM (mixed-effects model). Resting cardiac output, heart rate, and stroke volume were greater in pregnant women, without differences in blood pressure, ejection fraction, or cardiac mechanics. During free-breathing RE, pregnant women had a greater ejection fraction compared with nonpregnant women; however, all other hemodynamic variables were not different between groups. Cardiac mechanics during free-breathing RE across all intensities were not different between groups, with the exception that pregnant women had a lower apical circumferential strain that did not affect global cardiac function. No differences were observed between groups during 40% 10RM RE with and without VM. Pregnant women have proportionate cardiac responses to light-moderate RE, both with and without the VM. These findings reinforce the safety of RE in healthy pregnancy.

Exercise and physical activity in cirrhosis: opportunities or perils.

Reduced exercise capacity and impaired physical performance are observed in nearly all patients with liver cirrhosis. Physical activity and exercise are physiological anabolic stimuli that can reverse dysregulated protein homeostasis or proteostasis and potentially increase muscle mass and contractile function in healthy subjects. Cirrhosis is a state of anabolic resistance, and unlike the beneficial responses to exercise reported in physiological states, there are few systematic studies evaluating the response to exercise in cirrhosis. Hyperammonemia is a mediator of the liver-muscle axis with net skeletal muscle ammonia uptake in cirrhosis causing signaling perturbations, mitochondrial dysfunction with decreased ATP content, modifications of contractile proteins, and impaired ribosomal function, all of which contribute to anabolic resistance in cirrhosis and have the potential to impair the beneficial responses to exercise. English language-publications in peer-reviewed journals that specifically evaluated the impact of exercise in cirrhosis were reviewed. Most studies evaluated responses to endurance exercise, and readouts included peak or maximum oxygen utilization, grip strength, and functional capacity. Endurance exercise for up to 12 wk is clinically tolerated in well-compensated cirrhosis. Data on the safety of resistance exercise are conflicting. Nutritional supplements enhance the benefits of exercise in healthy subjects but have not been evaluated in cirrhosis. Whether the beneficial physiological responses with endurance exercise and increase in muscle mass with resistance exercise that occur in healthy subjects also occur in cirrhotics is not known. Specific organ-system responses, changes in body composition, or improved long-term clinical outcomes with exercise in cirrhosis need evaluation.

Exercise in patients with lymphedema: a systematic review of the contemporary literature

Controversy exists regarding the role of exercise in cancer patients with or at risk for lymphedema, particularly breast. We conducted a systematic review of the contemporary literature to distill the weight of the evidence and provide recommendations for exercise and lymphedema care in breast cancer survivors. Publications were retrieved from 11 major medical indices for articles published from 2004 to 2010 using search terms for exercise and lymphedema; 1,303 potential articles were selected, of which 659 articles were reviewed by clinical lymphedema experts for inclusion, yielding 35 articles. After applying exclusion criteria, 19 articles were selected for final review. Information on study design/objectives, participants, outcomes, intervention, results, and study strengths and weaknesses was extracted. Study evidence was also rated according to the Oncology Nursing Society Putting Evidence Into Practice® Weight-of-Evidence Classification. Seven studies were identified addressing resistance exercise, seven studies on aerobic and resistance exercise, and five studies on other exercise modalities. Studies concluded that slowly progressive exercise of varying modalities is not associated with the development or exacerbation of breast cancer-related lymphedema and can be safely pursued with proper supervision. Combined aerobic and resistance exercise appear safe, but confirmation requires larger and more rigorous studies. Strong evidence is now available on the safety of resistance exercise without an increase in risk of lymphedema for breast cancer patients. Comparable studies are needed for other cancer patients at risk for lymphedema. With reasonable precautions, it is safe for breast cancer survivors to exercise throughout the trajectory of their cancer experience, including during treatment.

Pression artérielle et musculation

Aim. – Heavy resistive training is associated with a markedly increase of blood pressure. This review aims to evaluate the mechanism of the blood pressure rise and its consequences. Current. – Resistance training include the use of both concentric and eccentric muscle actions and the performance of both single- and multiple-joint exercises. During heavy exercise, blood pressure increases significantly. Pressure response is related to the size of the muscular mass and strength, the number of recruited motor units, the type of contractions, the number of repetitions, the joint angle, the Valsalva maneuver. Blood pressure rise is reflexly elicited by a central control mechanism. Regular practice induce a modest blood pressure lowering effect, at rest, similar in dynamic exercise. Resistance training exerts favorable effects on cardiovascular function, muscle strength, bone and metabolism. Conclusion. – The safety of resistance exercise in healthy persons and men with low-risk cardiovascular disease is well established. Proper preliminary screening and close monitoring are important. Detailed participation criteria and prescriptive guidelines has been provided by the AHA and endorsed by the ACSM in 2000.