Maria M. Anton

Age-related declines in anaerobic muscular performance: weightlifting and powerlifting.

PURPOSE One approach to studying the effects of aging on physiological functional capacity (PFC) in humans is to analyze the peak physical performance of trained athletes with increasing age. The primary aim of the present study was to determine weightlifting and powerlifting performance with increasing age in both men and women. METHODS We performed a retrospective analysis of top age-group weightlifting and powerlifting records compiled from the U.S. Weightlifting and U.S. Powerlifting Organizations. RESULTS Regression analyses showed that in both men and women weightlifting and powerlifting performance declined curvilinearly and linearly, respectively. The rate and the overall magnitude of declines in performance with age were markedly greater (P < 0.05) in weightlifting than in powerlifting. The rates of age-related decline in muscular power were not different between upper body (bench press) and lower body (squat). Similarly, the age-related declines were not different between snatch and clean and jerk in weightlifting events. The magnitude of the declines with age was greater (P < 0.05) in women than in men in weightlifting; no such sex-related differences were observed in powerlifting performance. CONCLUSIONS The findings in this cross-sectional study indicate that 1) peak anaerobic muscular power, as assessed by peak lifting performance, decreases progressively even from earlier ages than previously thought; 2) the overall magnitude of decline in peak muscular power appears to be greater in tasks requiring more complex and powerful movements; 3) the age-related rates of decline are greater in women than in men only in the events that require more complex and explosive power; and 4) upper- and lower-body muscular power demonstrate similar rate of decline with age.

Effects of Combined Resistance and Endurance Training Versus Resistance Training Alone on Strength, Exercise Capacity, and Quality of Life in Patients With COPD.

PURPOSE: To compare the effects of 12-week training periods (2 d·wk−1) involving resistance training only with the effects of 12-week training periods involving combined resistance (once weekly) and endurance (once weekly) training on strength, endurance performance, and quality of life. METHODS: Thirty-six patients with moderate-to-severe chronic obstructive pulmonary disease were randomized to combined training (REG), resistance training alone (RG), or control (CG) groups. Patients were tested for maximal strength of the upper and lower extremities, power output of the lower extremities, maximal (W max) and submaximal exercise capacity, performance on a 6-minute walk test (6MWT), and quality of life. RESULTS: REG and RG induced similar maximal strength gains. Muscle power increased 19% (P ⩽ .01) and W max improved 13% (P < .05) in REG. Reductions (P < .05) in the heart rate and blood lactate at a given submaximal workload were observed in REG. Improvements in 6MWT and quality of life were similar in both training groups. CONCLUSIONS: Compared with a twice-weekly resistance training program, the combination of once-weekly resistance and once-weekly endurance training not only produced similar gains in maximal strength, 6MWT performance, and quality of life but also produced improvements in muscle power and endurance performance. These findings may have implications for the prescription of resistance and endurance exercise for patients with chronic obstructive pulmonary disease.

The effect of aging on adrenergic and nonadrenergic receptor expression and responsiveness in canine skeletal muscle

We tested the hypothesis that adrenergic and nonadrenergic receptor responsiveness and protein expression would be altered with advancing age. Young (n = 6; 22 ± 1 mo; mean ± SE) and old (n = 6; 118 ± 9 mo) beagles were instrumented with flow probes and an indwelling catheter for continuous measurement of external iliac blood flow and arterial blood pressure. Vascular conductance (VC) was calculated as hindlimb blood flow/mean arterial pressure. Selective agonists for α-1, α-2, neuropeptide-Y (NPY), and purinergic (P2X) receptors were infused at rest and during treadmill running at moderate (2.5 mph) and heavy (4 mph with 2.5% grade) exercise intensities. Feed arteries were dissected from gracilis muscles, and α-1D, α-1B, α-2A, P2X-4, P2X-1, and NPY-Y1 receptor protein expression was determined. Phenylephrine produced similar decreases (P > 0.05) in VC in young and old beagles at rest (young: -62 ± 5%; old: -59 ± 5%) and during moderate (young: -67 ± 5%; old: -62 ± 4%) and heavy (young: -54 ± 4%; old: -49 ± 3%) exercise. Clonidine caused similar (P > 0.05) decreases in VC in old compared with young dogs at rest (young: -59 ± 8%; old: -70 ± 6%) and during moderate (young: -52 ± 6%; old: -47 ± 5%)- and heavy (young: -42 ± 5%; old: -43 ± 5%)-intensity exercise. NPY infusion resulted in a similar decline in VC in young and old beagles at rest (young: -40 ± 7%; old: -39 ± 9%) and during moderate (young: -47 ± 6%; old: -40 ± 6%)- and heavy (young: -40 ± 3%; old: -38 ± 4%)-intensity exercise. α-β-Methylene-ATP also produced similar decreases in VC in young and old beagles at rest (young: -36 ± 6%; old: -40 ± 8%) and during exercise at moderate (young: -42 ± 5%; old: -40 ± 9%) and heavy (young: -47 ± 5%; old: -42 ± 8%) intensities. α-1B receptor protein expression was elevated (P < 0.05) in old compared with young dogs, whereas there were no age-related differences in α-1D or α-2A receptor expression and nonadrenergic P2X-4, P2X-1, and NPY-Y1 receptor expression. The present findings indicate that postsynaptic adrenergic and nonadrenergic receptor responsiveness was not altered by advancing age. Moreover, the expression of adrenergic and nonadrenergic receptors in skeletal-muscle feed arteries was largely unaffected by aging.

The Relationships Between Muscle Power and Physical Activity in Older Men With Chronic Obstructive Pulmonary Disease

The purpose of this study was to determine the potential relationship between muscle power of the lower extremities and the physical activity in older men with chronic obstructive pulmonary disease (COPD). Forty-four men (70.3 ± 6.7 years old) with moderate-to-severe COPD completed the 6-min walk test (6MWT), BODE (body mass index, obstruction, dyspnea, and exercise), a one-repetition maximum strength of the quadriceps femoris (1RMQF), and muscle power at 50% and 70% 1RMQF. Physical activity was measured using an accelerometer. The 6MWT was associated with muscle power at 50% 1RMQF (r = .40; P = .013) but not muscle power at 70% 1RMQF (r = .24; P = .15) or 1RMQF (r = .13; P = .44). Light-intensity activity was positively correlated with muscle power at 50% 1RMQF (r = .52; P = .001). Lower limb muscle power is associated with the 6MWT and light-intensity activities in older men with COPD.

Muscle power output in older adults with COPD

Introduction: Skeletal muscle power of the lower extremities decreases earlier than muscle strength with advancing age and is more strongly associated with functional performance of activities of daily living (e.g. rising from a chair, walking speed, and climb stairs) than maximal strength in the elderly population. In addition, increasing skeletal muscle power has been associated with a reduction in falls in older adults. It was hypothesized that skeletal muscle power would more strongly associated with functional exercise capacity than maximal strength in older men with chronic obstructive pulmonary disease (COPD). Objective: To determine the relationship between lower extremity skeletal muscle power and functional exercise capacity. Methods: Thirty-five men (aged 70 ± 5) with moderate to severe COPD were tested for thigh muscle mass, maximal strength (1RM), power output of the lower extremities at 50% and 70% 1RM, six minute walking (6MW) distance, and peak oxygen uptake. Results: The 6MW distance was positively associated with power output at 50% 1RM (r= 0.64; p Conclusions: Muscle power output is strongly associated with the 6MW distance than maximal strength. Furthermore, pulmonary rehabilitation programs that include lower extremity muscle power training should be prescribed to older adults with COPD. Support by of the Spanish Ministry of Education and Science DEP2011-30042-C02-01; DEP2011-30042-C01-02.

Arterial Compliance of Rowers: Implications for Combined Aerobic and Strength Training on Arterial Elasticity

Regular endurance exercise increases central arterial compliance, whereas resistance training decreases it. It is not known how the vasculature adapts to a combination of endurance and resistance training. Rowing is unique, because its training encompasses endurance- and strength-training components. We used a cross-sectional study design to determine arterial compliance of 15 healthy, habitual rowers [50 +/- 9 (SD) yr, 11 men and 4 women] and 15 sedentary controls (52 +/- 8 yr, 10 men and 5 women). Rowers had been training 5.4 +/- 1.2 days/wk for 5.7 +/- 4.0 yr. The two groups were matched for age, body composition, blood pressure, and metabolic risk factors. Central arterial compliance (simultaneous ultrasound and applanation tonometry on the common carotid artery) was higher (P < 0.001) and carotid beta-stiffness index was lower (P < 0.001) in rowers than in sedentary controls. There were no group differences for measures of peripheral (femoral) arterial stiffness. The higher central arterial compliance in rowers was associated with a greater cardiovagal baroreflex sensitivity, as estimated during a Valsalva maneuver (r = 0.54, P < 0.005). In conclusion, regular rowing exercise in middle-aged and older adults is associated with a favorable effect on the elastic properties of the central arteries. Our results suggest that simultaneously performed endurance training may negate the stiffening effects of strength training.