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Purpose: Walking net V ˙ O2 tends to increase with advancing age; however, factors contributing to this relationship have not been widely described. The implications of such findings could inform targeted strategies to promote independent mobility in older adults. Herein, we evaluated the relationship between net V ˙ O2 and age at two submaximal workloads while exploring potential moderators of this relationship. Methods: Secondary analyses were performed on 35 older (65 ± 3 years) women who completed a battery of physical assessments including fixed-speed, non-graded and graded (+ 2.5%) treadmill walking with indirect calorimetry to determine net V ˙ O2. Maximal oxygen uptake ( V ˙ O2max), knee extensor maximal isometric voluntary contraction (MVC), peak rate of torque development (RTD), and plantar flexor range-of-motion (PFROM) were also measured. Results: Bivariate correlations showed non-graded (r = 0.403, p = 0.017) and graded (r = 0.413, p = 0.014) net V ˙ O2 were positively related to age. Notably, these relationships strengthened after adjusting for V ˙ O2max. Regression modeling showed age, RTD:MVC ratio (composite of muscle performance), and PFROM together explained 49% and 34% of the variance in non-graded and graded net V ˙ O2, respectively. Further analyses suggested knee extensor MVC moderates the relationship between non-graded net V ˙ O2 and age, accounting for 9% of the variance [ΔR2 = 0.090, F (1,31) = 4.13, p = 0.05]. Conclusion: These data support the premise that, in older women, walking net V ˙ O2 rises with advancing age, and additionally, the RTD:MVC ratio and PFROM are independent correlates of non-graded net V ˙ O2. Exercise interventions with a high degree of training specificity including explosive, velocity-based elements may promote independent mobility in older women. [ABSTRACT FROM AUTHOR]

Eccentric muscle contractions can cause structural damage to muscle cells resulting in temporarily decreased muscle force production and soreness. Prior work indicates pasture-raised dairy products from grass-fed cows have greater anti-inflammatory and antioxidant properties compared to grain-fed counterparts. However, limited research has evaluated the utility of whey protein from pasture-raised, grass-fed cows to enhance recovery compared to whey protein from non-grass-fed cows. Therefore, using a randomized, placebo-controlled design, we compared the effect of whey protein from pasture-raised, grass-fed cows (PRWP) to conventional whey protein (CWP) supplementation on indirect markers of muscle damage in response to eccentric exercise-induced muscle damage (EIMD) in resistance-trained individuals. Thirty-nine subjects (PRWP, n = 14; CWP, n = 12) completed an eccentric squat protocol to induce EIMD with measurements performed at 24, 48, and 72 h of recovery. Dependent variables included: delayed onset muscle soreness (DOMS), urinary titin, maximal isometric voluntary contraction (MIVC), potentiated quadriceps twitch force, countermovement jump (CMJ), and barbell back squat velocity (BBSV). Between-condition comparisons did not reveal any significant differences (p ≤ 0.05) in markers of EIMD via DOMS, urinary titin, MIVC, potentiated quadriceps twitch force, CMJ, or BBSV. In conclusion, neither PRWP nor CWP attenuate indirect markers of muscle damage and soreness following eccentric exercise in resistance-trained individuals. [ABSTRACT FROM AUTHOR]

Background/Objectives To test the effects of weight loss with and without exercise training (aerobic or resistance) on intra-abdominal adipose tissue (IAAT) and risk factors for cardiovascular disease (CVD). Additionally, CVD risk factors was evaluated before and after weight loss using previously established IAAT cut-points. Subjects/Methods One hundred twenty-two overweight premenopausal women were randomly assigned to one of three groups: (1) diet only (Diet); (2) diet and aerobic training (Diet + AT); or (3) diet and resistance training (Diet + RT); until a BMI of < 25 kg/m.sup.2 was reached. Computerized tomography was used to measure IAAT and blood lipids were measured by assay. Evaluations were made before and after weight loss. Results Though no group-by-time effects were found after weight loss, we observed significant time effects for: IAAT (-38.0%, P < 0.001), total cholesterol (TC) (-2.2%, P = 0.008), low-density lipoprotein cholesterol (LDL-C) (-4.8%, P < 0.001), high-density lipoprotein cholesterol (HDL-C) (+20.2%, P < 0.001), triglycerides (-18.7%, P < 0.001), TC/HDL-C (-16.3%, P < 0.001), and LDL-C/HDL-C (-18.0%, P < 0.001). Following weight loss, 40.2% of all participants reduced IAAT to < 40 cm.sup.2 (IAAT associated with low CVD risk). Furthermore, only 2.5% of participants had an IAAT > 110 cm.sup.2 (IAAT associated with high CVD risk) after weight loss. We also observed that decreases of IAAT were associated with decreased CVD risk factors after weight loss independent of race, changes in %fat mass and changes in maximal oxygen uptake. Conclusions Caloric restriction leading to significant weight loss with or without exercise training appears to be equally effective for reducing IAAT and CVD risk factors., Author(s): Juliano H. Borges [sup.1] [sup.2] , Stephen J. Carter [sup.1] , David R. Bryan [sup.1] , Gary R. Hunter [sup.1] Author Affiliations: (1) Department of Nutrition Sciences, University of [...]

We tested the hypothesis that women may be more at risk of becoming dehydrated during physical work in the heat in the early follicular phase (EF), compared with the late follicular (LF) and mid-luteal (ML) phases of the menstrual cycle when allowed free access to drink. Twelve healthy, eumenorrheic, unacclimated women (26 ± 5 yr) completed three trials (EF, LF, and ML phases) involving 4 h of exposure to 33.8 ± 0.8 °C, 54 ± 1% relative humidity. Each hour, participants walked on a treadmill for 30 min at a rate of metabolic heat production of 338 ± 9 W. Participants drank a cool, flavor-preferred non-caloric sport drink ad libitum. Nude body weight was measured pre- and post-exposure, and percent changes in body weight loss were interpreted as an index of changes in total body water. Total fluid intake and urine output were measured and sweat rate was estimated from changes in body mass corrected for fluid intake and urine output. Fluid intake was not different between phases (EF: 1,609 ± 919 mL; LF: 1,902 ± 799 mL; ML: 1,913 ± 671; P = 0.202). Total urine output (P = 0.543) nor sweat rate (P = 0.907) differed between phases. Percent changes in body mass were not different between phases (EF: -0.5 ± 0.9%; LF: -0.3 ± 0.9%; ML: -0.3 ± 0.7%; P = 0.417). This study demonstrates that the normal hormonal fluctuations that occur throughout the menstrual cycle do not alter fluid balance during physical work in the heat. [ABSTRACT FROM AUTHOR]