Normal Ribosomal Biogenesis but Shortened Protein Synthetic Response to Acute Eccentric Resistance Exercise in Old Skeletal Muscle.

Anabolic resistance to feeding in aged muscle is well-characterized; however, whether old skeletal muscle is intrinsically resistant to acute mechanical loading is less clear. The aim of this study was to determine the impact of aging on muscle protein synthesis (MPS), ribosome biogenesis, and protein breakdown in skeletal muscle following a single bout of resistance exercise. Adult male F344/BN rats aged 10 (Adult) and 30 (Old) months underwent unilateral maximal eccentric contractions of the hindlimb. Precursor rRNA increased early post-exercise (6-18 h), preceding elevations in ribosomal mass at 48 h in Adult and Old; there were no age-related differences in these responses. MPS increased early post-exercise in both Adult and Old; however, at 48 h of recovery, MPS returned to baseline in Old but not Adult. This abbreviated protein synthesis response in Old was associated with decreased levels of IRS1 protein and increased BiP, CHOP and eIF2α levels. Other than these responses, anabolic signaling was similar in Adult and Old muscle in the acute recovery phase. Basal proteasome activity was lower in Old, and resistance exercise did not increase the activity of either the ATP-dependent or independent proteasome, or autophagy (Cathepsin L activity) in either Adult or Old muscle. We conclude that MPS and ribosome biogenesis in response to maximal resistance exercise in old skeletal muscle are initially intact; however, the MPS response is abbreviated in Old, which may be the result of ER stress and/or blunted exercise-induced potentiation of the MPS response to feeding

Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study

Background: It is well documented that exercise-induced muscle damage (EIMD) decreases muscle function and causes soreness and discomfort. Branched-chain amino acid (BCAA) supplementation has been shown to increase protein synthesis and decrease muscle protein breakdown, however, the effects of BCAAs on recovery from damaging resistance training are unclear. Therefore, the aim of this study was to examine the effects of a BCAA supplementation on markers of muscle damage elicited via a sport specific bout of damaging exercise in trained volunteers. Methods: Twelve males (mean ± SD age, 23 ± 2 y; stature, 178.3 ± 3.6 cm and body mass, 79.6 ± 8.4 kg) were randomly assigned to a supplement (n = 6) or placebo (n = 6) group. The damaging exercise consisted of 100 consecutive drop-jumps. Creatine kinase (CK), maximal voluntary contraction (MVC), muscle soreness (DOMS), vertical jump (VJ), thigh circumference (TC) and calf circumference (CC) were measured as markers of muscle damage. All variables were measured immediately before the damaging exercise and at 24, 48, 72 and 96 h post-exercise. Results: A significant time effect was seen for all variables. There were significant group effects showing a reduction in CK efflux and muscle soreness in the BCAA group compared to the placebo (P < 0.05). Furthermore, the recovery of MVC was greater in the BCAA group (P < 0.05). The VJ, TC and CC were not different between groups. Conclusion: The present study has shown that BCAA administered before and following damaging resistance exercise reduces indices of muscle damage and accelerates recovery in resistance-trained males. It seems likely that BCAA provided greater bioavailablity of substrate to improve protein synthesis and thereby the extent of secondary muscle damage associated with strenuous resistance exercise. Clinical Trial Registration Number: NCT01529281

Repeat exercise normalizes the gas-exchange impairment induced by a previous exercise bout in asthmatic subjects

Twenty-one subjects with asthma underwent treadmill exercise to exhaustion at a workload that elicited approximately 90% of each subject's maximal O2 uptake (EX1). After EX1, 12 subjects experienced significant exercise-induced bronchospasm [(EIB+), %decrease in forced expiratory volume in 1.0 s = -24.0 +/- 11.5%; pulmonary resistance at rest vs. postexercise = 3.2 +/- 1.5 vs. 8.1 +/- 4.5 cmH2O.l(-1).s(-1)] and nine did not (EIB-). The alveolar-to-arterial Po2 difference (A-aDo2) was widened from rest (9.1 +/- 6.7 Torr) to 23.1 +/- 10.4 and 18.1 +/- 9.1 Torr at 35 min after EX1 in subjects with and without EIB, respectively (P < 0.05). Arterial Po2 (PaO2) was reduced in both groups during recovery (EIB+, -16.0 +/- -13.0 Torr vs. baseline; EIB-, -11.0 +/- 9.4 Torr vs. baseline, P < or = 0.05). Forty minutes after EX1, a second exercise bout was completed at maximal O2 uptake. During the second exercise bout, pulmonary resistance decreased to baseline levels in the EIB+ group and the A-aDo2 and PaO2 returned to match the values seen during EX1 in both groups. Sputum histamine (34.6 +/- 25.9 vs. 61.2 +/- 42.0 ng/ml, pre- vs. postexercise) and urinary 9alpha,11beta-prostaglandin F2 (74.5 +/- 38.6 vs. 164.6 +/- 84.2 ng/mmol creatinine, pre- vs. postexercise) were increased after exercise only in the EIB+ group (P < 0.05), and postexercise sputum histamine was significantly correlated with the exercise PaO2 and A-aDo2 in the EIB+ subjects. Thus exercise causes gas-exchange impairment during the postexercise period in asthmatic subjects independent of decreases in forced expiratory flow rates after the exercise; however, a subsequent exercise bout normalizes this impairment secondary in part to a fast acting, robust exercise-induced bronchodilatory response

Exploring the feasibility, sustainability and the benefits of the GrACE + GAIT exercise programme in the residential aged care setting

Fien, S ORCiD: 0000-0003-0181-5458Background: The feasibility and benefits of a 24-week targeted progressive supervised resistance and weight-bearing exercise programme (Group Aged Care Exercise + GAIT (GrACE + GAIT)) in the residential aged care (RAC) setting was investigated as very little peer-reviewed research has been conducted in relation to exercise programmes of this duration in this cohort. Methods: A quasi-experimental study design consisting of two groups (control and exercise) explored a 24-week targeted progressive supervised resistance and weight-bearing exercise programme (GrACE + GAIT) in two RAC facilities in Northern New South Wales, Australia. A total of 42 adults consented to participate from a total of 68 eligible residents (61.7%). The primary outcome measures were feasibility and sustainability of the exercise programme via intervention uptake, session adherence, attrition, acceptability and adverse events. Secondary measures included gait speed and the spatio-temporal parameters of gait, handgrip muscle strength and sit to stand performance. Results: Twenty-three residents participated in the exercise intervention (mean (SD) 85.4 (8.1) years, 15 females) and 19 in the control group (87.4 (6.6) years 13 females). Exercise adherence was 79.3%, with 65% of exercise participants attending ≥70% of the sessions; 100% of those originally enrolled completed the programme and strongly agreed with the programme acceptability. Zero exercise-related adverse events were reported. ANCOVA results indicated that post-intervention gait speed significantly increased (p < 0.001) with an 18.8% increase in gait speed (m/s). Discussion: The GrACE + GAIT programme was shown to be feasible and significantly improve adults living in RAC facilities gait speed, handgrip strength and sit to stand performance. These results suggest that the GrACE + GAIT programme is suitable for use in the RAC sector and that it has the potential to reduce disability and improve function and quality of life of the residents

Cardio-Protection Afforded by Β-Blockade Is Maintained During Resistance Exercise

Objectives Whether or not the cardio-protective effect of β-adrenergic blockade is retained during resistance exercise has not been systematically evaluated. Therefore the purpose of this study was to measure selected cardiorespiratory responses to isometric exercise involving hand-gripping, single-leg extension, or double-leg dead-lift, under placebo (control), β1-selective (atenolol), and non-selective (propranolol) adrenergic blockade conditions. Design Eleven young male adults were evaluated in a randomized, double-blinded, repeated measures study design and performed all three exercise modalities at 30% of maximal voluntary contraction under placebo, atenolol and propranolol conditions. Methods Heart rate, systolic and diastolic blood pressure, rate-pressure product, oxygen uptake, cardiac output, stroke volume and total peripheral resistance were directly measured or calculated at rest and during the third minute of each of the three exercise modes. Results Irrespective of drug condition, a graded pressor response was observed going from rest to exercise so that rest \u3c handgrip \u3c leg extension \u3c dead-lift for heart rate, systolic and diastolic blood pressures, rate-pressure product and oxygen uptake (p \u3c 0.05 for all). Cardiac output only increased with the dead-lift mode of exercise (p \u3c 0.01). Importantly β-adrenergic blockade with either atenolol or propranolol similarly attenuated the rise in heart rate, and systolic blood pressure; thus rate-pressure product demonstrated a mode-of-exercise by drug interaction effect (p \u3c 0.001) with the greatest reductions seen with the dead-lift procedure. Conclusions The findings indicate that cardio-protection afforded by selective or non-selective β-blockade at rest is preserved during isometric exercise and even enhanced once heart rate increases above 100 beats min−1

Renal function and physical fitness after 12-mo supervised training in kidney transplant recipients

To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations

The effects of resistance training on mood following an autonomous vs. yoked protocol

textBackground. Previous research has shown that an individual’s post-exercise mood plays an important role in their likelihood to participate in that exercise activity in the future (Emmons & Diener, 1986; Williams et al., 2008; Williams et al., 2012). Of the possible moderating variables in the exercise-affect relationship, exercise intensity shows the most support. However, an uncoupling effect manifested in Parffit, Rose, & Burgess (2006) showed that self-selecting the intensity acted as an affective buffer and essentially allowed participants to exercise at higher intensity without the expected drop in affect. It may be, therefore, that autonomy may further serve to moderate the impact of exercise on mood. Design. To explore this issue, we employed a "yoked" design (Dickerson & Creedon, 1981). Participants were randomly assignment to either a free-choice resistance exercise, or a yoked control. The yoked participant performs a bout of exercise that matches the selection of their autonomous counterpart. In this study, 14 college-aged students participated in a testing session to estimate 1-repetition maximums, and a resistance exercise session that was either autonomous (self-selected) or a relative replication (yoked). Participants completed mood questionnaires following the resistance exercise session. Results. A 2 (group) x 3 (time) with repeated measures on the second factor showed significant main effects of time for the Felt Arousal Scale F(2, 13) = 4.15, p = .05 and Negative Affect F(2, 11) = 4.28, p = .05 such that arousal and negative affect both declined during recovery. Additionally, five of the seven yoked participants were unable to progress through their relative resistance exercise bout without a decrease in weight in order to achieve the prescribed number of repetitions. Conclusion. Autonomy does not appear to be a critical component of affect following resistance training. Further research is needed to explore resistance training as a model of autonomy manipulation, and to test the possibility of a performance detriment accompanying a loss of autonomy.Kinesiology and Health Educatio

Effect of whey protein isolate on strength, body composition and muscle hypertrophy during resistance training

Purpose of Review: Sarcopenia (skeletal muscle wasting with aging) is thought to underlie a number of serious age-related health issues. While it may be seen as inevitable, decreasing this gradual loss of muscle is vital for healthy aging. Thus, it is imperative to investigate exercise and nutrition-based strategies designed to build a reservoir of muscle mass as early as possible. Recent Findings: Elderly individuals are still able to respond to both resistance training and the anabolic signals provided by protein ingestion, provided specific amino acids, such as leucine, are present. Whey proteins are a rich source of these essential amino acids and rapidly elevate plasma amino acids, thus providing the foundations for preservation of muscle mass. Several studies involving supplementation with whey protein have shown to be effective in augmenting the effects of resistance exercise, in particular when supplementation occurs in the hours surrounding the exercise training. Summary: While further work is required, particularly in elderly people, simple dietary and exercise strategies that may improve the maintenance of skeletal muscle mass will likely result in a decrease in the overall burden of a number of diseases and improve the quality of life as we age

Questioning the Resistance/Aerobic Training Dichotomy: A commentary on physiological adaptations determined by effort rather than exercise modality

This paper discusses and challenges the current opinion that exercise adaptation is generally defined by modality; resistance exercise (RE), or aerobic exercise (AE). In presenting a strong body of recent research which demonstrably challenges these perceptions we suggest alternate hypotheses towards physiological adaptation which is hinged more upon the effort than the exercise modality. Practical implications of this interpretation of exercise adaptation might effect change in exercise adherence since existing barriers to exercise of time, costs, specialized equipment, etc. become nullified. In presenting the evidence herein we suggest that lay persons wishing to attain the health and fitness (including strength and muscle hypertrophy) benefits of exercise can choose from a wide range of potential exercise modalities so long as the effort is high. Future research should consider this hypothesis by directly comparing RE and AE for acute responses and chronic adaptations

Exercise interventions for adults and children with cerebral palsy (Protocol)

This is the protocol for a review and there is no abstract. The objectives are as follows: - The primary aim of this systematic review is to evaluate the effect of exercise interventions on activity, participation, and health-related quality of life (HRQoL) in adults and children with CP. - The secondary aim is to evaluate the effect of exercise interventions on body functions and body structures.Jennifer M Ryan is receiving funding from Action Medical Research and the Chartered Society of Physiotherapy Charitable Trust to evaluate the feasibility, acceptability, and efficacy of resistance training in adolescents with cerebral palsy