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Purpose: While several studies have documented isokinetic knee strength in junior and senior rugby league players, investigations of isokinetic knee and hip strength in professional rugby union players are limited. The purpose of this study was to provide lower-extremity strength profiles and compare isokinetic knee and hip strength of professional rugby league and rugby union players. Participants: 32 professional rugby league and 25 professional rugby union players. Methods: Cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque and strength ratios of the dominant and nondominant legs during seated knee-extension/ flexion and supine hip-extension/flexion actions at 60°/s. Results: Forwards from both codes were taller and heavier and had a higher body-mass index than the backs of each code. Rugby union forwards produced significantly (P < .05) greater peak torque during knee flexion in the dominant and nondominant legs (ES = 1.81 and 2.02) compared with rugby league forwards. Rugby league backs produced significantly greater hip-extension peak torque in the dominant and nondominant legs (ES = 0.83 and 0.77) compared with rugby union backs. There were no significant differences in hamstring-to-quadriceps ratios between code, position, or leg. Rugby union forwards and backs produced significantly greater knee-flexion-to-hip-extension ratios in the dominant and nondominant legs (ES = 1.49-2.26) than rugby union players. Conclusions: It seems that the joint torque profiles of players from rugby league and union codes differ, which may be attributed to the different demands of each code. [ABSTRACT FROM AUTHOR]

The purpose of this study was to quantify the inter-session reliability of force–velocity–power profiling and estimated maximal strength in youth. Thirty-six males (11–15 years old) performed a ballistic supine leg press test at five randomized loads (80%, 100%, 120%, 140%, and 160% body mass) on three separate occasions. Peak and mean force, power, velocity, and peak displacement were collected with a linear position transducer attached to the weight stack. Mean values at each load were used to calculate different regression lines and estimate maximal strength, force, velocity, and power. All variables were found reliable (change in the mean [CIM] = − 1 to 14%; coefficient of variation [CV] = 3–18%; intraclass correlation coefficient [ICC] = 0.74–0.99), but were likely to benefit from a familiarization, apart from the unreliable maximal force/velocity ratio (CIM = 0–3%; CV = 23–25%; ICC = 0.35–0.54) and load at maximal power (CIM = − 1 to 2%; CV = 10–13%; ICC = 0.26–0.61). Isoinertial force–velocity–power profiling and maximal strength in youth can be assessed after a familiarization session. Such profiling may provide valuable insight into neuromuscular capabilities during growth and maturation and may be used to monitor specific training adaptations. [ABSTRACT FROM PUBLISHER]

Background: Vitamin C (ascorbate) is likely to be essential for skeletal muscle structure and function via its role as an enzyme cofactor for collagen and carnitine biosynthesis. Vitamin C may also protect these metabolically active cells from oxidative stress. Objective: We investigated the bioavailability of vitamin C to human skeletal muscle in relation to dietary intake and plasma concentrations and compared this relation with ascorbate uptake by leukocytes. Design: Thirty-six nonsmoking men were randomly assigned to receive 6 wk of 0.5 or 2 kiwifruit/d, an outstanding dietary source of vitamin C. Fasting blood samples were drawn weekly, and 24-h urine and leukocyte samples were collected before intervention, after intervention, and after washout. Needle biopsies of skeletal muscle (vastus lateralis) were carried out before and after intervention. Results: Baseline vastus lateralis ascorbate concentrations were ~16 nmol/g tissue. After intervention with 0.5 or 2 kiwifruit/d, these concentrations increased 3.5-fold to 53 and 61 nmol/g, respectively. There was no significant difference between the responses of the 2 groups. Mononuclear cell and neutrophil ascorbate concentrations increased only ~1.5- and ~2-fold, respectively. Muscle ascorbate concentrations were highly correlated (P < 0.001) with dietary intake (R = 0.61) and plasma concentrations (R = 0.75) in the range from 5 to 80 μmol/L. Conclusions: Human skeletal muscle is highly responsive to vitamin C intake and plasma concentrations and exhibits a greater relative uptake of ascorbate than leukocytes. Thus, muscle appears to comprise a relatively labile pool of ascorbate and is likely to be prone to ascorbate depletion with inadequate dietary intake. [ABSTRACT FROM AUTHOR]

The prevalence of overweight and obesity is increasing worldwide at an alarming rate. An Internet-based weight-loss programme has the potential to reach larger numbers of people than traditional face-to-face programmes. A growing body of evidence supports the use of low glycaemic load (GL) diets for weight loss. The present study aimed to investigate the efficacy of an Internet-based weight-loss programme that included foods with a low GL. One hundred and three volunteers, with a body mass index (BMI) ≥28 kg m, enrolled into an Internet weight-loss programme. A dietitian counselled participants over the Internet via weekly interactive chat rooms and monthly e-mails. Participants self-recorded body weight and food intake directly on to the Internet site. Weight, BMI and waist circumference were measured, and dietary data collected, at baseline and 6 months. Seventy participants completed the 6-month weight-loss programme. Among these, mean weight, BMI and waist circumference significantly decreased by 3.5 kg (95% CI = 2.3-4.7), 1.2 kg m (95% CI = 0.8-1.7) and 4.8 cm (95% CI = 2.8-6.8), of baseline values respectively ( P < 0.001). Twenty-five (36%) of the 70 participants lost a clinically significant amount of weight (>5% of initial body weight). This descriptive study has shown that an Internet-based weight-loss programme with low GL principles can promote weight loss. This type of intervention and approach could be used to enhance other weight-loss strategies. [ABSTRACT FROM AUTHOR]

Research measuring whole-body protein turnover (WBPT) after both exercise and nutrition has generally focused on resistance exercise; however, there is a paucity of data regarding the effect of postaerobic exercise nutrition, especially in older adults. It is not known if postexercise protein feeding has a beneficial effect on protein turnover after low- to moderate-intensity exercise. We investigated whether consuming protein plus carbohydrate (PRO) immediately after an acute bout of aerobic exercise has an additive effect over carbohydrate alone (CHO) on WBPT in older individuals. Twelve healthy older adults (age, 59 ± 4 years) were studied on 2 separate occasions after 1 h of exercise at approximately 50% of maximal rate of oxygen uptake, followed by 4 h of recovery. Immediately following exercise, subjects ingested a CHO (60 g) or an isocaloric PRO beverage (40 g carbohydrate, 20 g whey protein). Whole-body protein metabolism was determined using [1-13C]leucine infusion (60 mg prime; 75 mg·h-1 continuous), and sampling blood and expired breath. Rates of whole-body leucine appearance and oxidation, and nonoxidative leucine disposal during the third and fourth hours of postexercise recovery were higher in the PRO group (2.51 ± 0.55, 0.78 ± 0.37, and 1.71 ± 0.44 µmol·kg-1·min-1, respectively) than in the CHO group (1.81 ± 0.27, 0.33 ± 0.14, and 1.47 ± 0.25 µmol·kg-1·min-1, respectively; p = 0.001). Our results indicate that consumption of a PRO beverage after aerobic exercise increased WBPT to a greater extent than a CHO beverage. Les études s'intéressant à la mesure du renouvellement global des protéines dans l'organisme (WBPT) à la suite d'un exercice physique et d'un apport alimentaire traitent généralement du rôle des exercices de force; néanmoins, il y a peu d'études sur les effets d'un apport alimentaire à la suite d'un exercice aérobie particulièrement chez les personnes âgées. On ne sait pas si un apport protéique après un exercice suscite un effet bénéfique sur le renouvellement protéique consécutif à un exercice d'intensité légère à modérée. Cette étude se propose de vérifier si, comparativement à un apport de sucres seulement (CHO), un apport protéique combiné à des sucres (PRO) immédiatement après un bref effort aérobie apporte des effets additionnels concernant le WBPT chez des personnes âgées. On invite en deux occasions douze adultes en bonne santé et âgés de 59 ± 4 ans à participer à une séance d'exercice d'une durée de 60 min et d'intensité suscitant 50 % du consommation d'oxygene maximale suivie d'une récupération d'une durée de 4 h. Immédiatement après la fin de l'exercice, les sujets consomment soit une boisson contenant des sucres (CHO; 60 g) soit une boisson contenant des sucres et des protéines (PRO; 40 g de sucres et 20 g de protéines lactosériques) totalisant la même quantité d'énergie. On évalue le métabolisme protéique de l'organisme en entier par l'administration de [1-13C] leucine (infusion immédiate de 60 mg suivie d'une perfusion à raison de 75 mg·h-1) et l'analyse des échantillons de sang et des gaz expirés. Les taux corporels d'apparition de la leucine, de son oxydation et de l'élimination de la fraction non oxydée au cours de la 3e et de la 4e heure de la période de récupération postexercice sont plus importants dans la condition PRO (2,51 ± 0,55, 0,78 ± 0,37 et 1,71 ± 0,44 μmol·kg-1·min-1 respectivement) que dans la condition CHO (1,81 ± 0,27, 0,33 ± 0,14 et 1,47 ± 0,25 μmol·kg-1·min-1 respectivement) (p = 0,001). Nos observations révèlent qu'un apport de protéines à la suite d'un exercice aérobie suscite une plus grande augmentation du WBPT que ne le fait un apport de sucres. Un apport protéique à la suite d'un exercice semble favorable à l'amélioration de la qualité des protéines contenues dans l'organisme en entier et pourrait apporter des gains en matière de capacité physique chez les personnes âgées. [ABSTRACT FROM AUTHOR]

Aim: To investigate the bone health and associated risk factors of a group of South Asian women living in New Zealand. Studies on the Indian subcontinent suggest a high incidence of low bone mineral density in women with poor vitamin D status and low dietary calcium intake. Methods: Subjects were women of South Asian origin (n = 91) living in Auckland, New Zealand. Subjects were stratified by menopausal status. They completed a 4-day food diary, and provided a fasting blood sample. Bone mineral density was measured in the lumbar spine and proximal femur using dual X-ray densitometry. Results: Mean age of premenopausal (n = 71) and postmenopausal (n = 20) women was 39.8 ± 7.8 and 55.3 ± 5.4 years, respectively. Osteoporosis ( T-score ≤−2.5) was present in 32% of postmenopausal and 3% of premenopausal subjects, but only in the lumbar spine. Adequate 25(OH)D levels (>50 nmol/L) were found in only 22% of premenopausal, and 26% of postmenopausal women. A body mass index in the overweight or obese category was found in 61% of premenopausal and 75% of postmenopausal women. Conclusion: The high incidence of osteoporosis in the postmenopausal group could be associated with the early age of oophorectomy or menopause together with low vitamin D status. [ABSTRACT FROM AUTHOR]