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Can exercise training enhance the repeated remote ischaemic preconditioning stimulus on peripheral and cerebrovascular function in high-risk individuals?
Maxwell, JD, France, M, Finnigan, LEM, Carter, HH, Thijssen, DHJ, Jones, H
European journal of applied physiology. 2021;(4):1167-1178
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Abstract
BACKGROUND Repeated exposure to remote ischaemic preconditioning (rIPC; short bouts of non-lethal ischaemia) enhances peripheral vascular function within 1 week; whereas, longer periods of rIPC (~ 1 year) may improve cerebral perfusion. Increasing the 'dose' of rIPC may lead to superior effects. Given the similarities between exercise and rIPC, we examined whether adding exercise to the rIPC stimulus leads to greater adaptation in systemic vascular function. METHODS Nineteen individuals with increased risk for cardiovascular disease (CVD) were randomly allocated to either 8 weeks of rIPC (n = 9) or 8 weeks of rIPC + exercise (rIPC + Ex) (n = 10). rIPC was applied three times per week in both conditions, and exercise consisted of 50 min (70% heart rate max) of cycling 3 times per week. Peripheral endothelial function was assessed using flow-mediated dilation (FMD) before and after ischaemia-reperfusion (IR). Cerebrovascular function was assessed by dynamic cerebral autoregulation (dCA) and cerebrovascular reactivity (CVR), and cardio-respiratory fitness (VO2peak) using a maximal aerobic capacity test. RESULTS FMD% increased by 1.6% (95% CI, 0.4, 2.8) following rIPC + Ex and by 0.3% (- 1.1, 1.5) in the only rIPC but this did not reach statistical significance (P = 0.65). Neither intervention evoked a change in dCA or in CVR (P > 0.05). VO2peak increased by 2.8 ml/kg/min (1.7, 3.9) following the rIPC + Ex and by 0.1 ml/kg/min (- 1.0, 1.4) following the rIPC only intervention (P = 0.69). CONCLUSION Combining exercise with rIPC across an 8-week intervention does not lead to superior effects in cerebrovascular and peripheral vascular function compared to a repeated rIPC intervention in individuals at risk of CVD.
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Effect of a single bout of morning or afternoon exercise on glucose fluctuation in young healthy men.
Tanaka, Y, Ogata, H, Park, I, Ando, A, Ishihara, A, Kayaba, M, Yajima, K, Suzuki, C, Araki, A, Osumi, H, et al
Physiological reports. 2021;(7):e14784
Abstract
The timing of exercise plays an important role in the effect of the exercise on physiological functions, such as substrate oxidation and circadian rhythm. Exercise exerts different effects on the glycemic response to exercise and meal intake depending on when the exercise performed. Here, we comprehensively investigated the effects of the timing (morning or afternoon) of exercise on glucose fluctuation on the basis of several indices: glycemic variability over 24 h (24-h SD), J-index, mean amplitude of glucose excursions (MAGE), continuous overall net glycemic action (CONGA), and detrended fluctuation analysis (DFA). Eleven young men participated in 3 trials in a repeated measures design in which they performed a single bout of exercise at 60% of their maximal oxygen uptake for 1 h beginning either at 7:00 (morning exercise), 16:00 (afternoon exercise), or no exercise (control). Glucose levels were measured using a continuous glucose monitoring system (CGMs). Glucose fluctuation was slightly less stable when exercise was performed in the afternoon than in the morning, indicated by higher CONGA at 2 h and α2 in DFA in the afternoon exercise trial than in the control trial. Additionally, decreased stability in glucose fluctuation in the afternoon exercise trial was supported by the descending values of the other glucose fluctuation indices in order from the afternoon exercise, morning exercise, and control trials. Meal tolerance following exercise was decreased after both exercise trials. Glucose levels during exercise were decreased only in the afternoon exercise trial, resulting in less stable glucose fluctuations over 24 h.
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Effect of six weeks 1000 mg/day vitamin C supplementation and healthy training in elderly women on genes expression associated with the immune response - a randomized controlled trial.
Żychowska, M, Grzybkowska, A, Zasada, M, Piotrowska, A, Dworakowska, D, Czerwińska-Ledwig, O, Pilch, W, Antosiewicz, J
Journal of the International Society of Sports Nutrition. 2021;(1):19
Abstract
BACKGROUND In this study, we investigated the effects of supplementation and exercise on the expression of genes associated with inflammation like CCL2, CRP, IL1, IL6, IL10 mRNA in elderly women. METHODS Twenty four participants divided randomly into two groups were subjected to 6 weeks of the same health training program (three times per week). SUP group (supplemented, n = 12, mean age 72.8 ± 5.26 years and mean body mass 68.1 ± 8.3 kg) received 1000 mg of Vitamin C/day during the training period, while CON group (control, n = 12, mean age 72.4 ± 5.5 years and body mass 67.7 ± 7.5 kg) received placebo. RESULTS No significant changes in IL-1, IL-6, IL-10 and CRP mRNA were observed within and between groups. However, there was a clear tendency of a decrease in IL-6 (two-way ANOVA, significant between investigated time points) and an increase in IL-10 mRNA noted in the supplemented group. A significant decrease in CCL2 mRNA was observed only in the CON group (from 2^0.2 to 2^0.1, p = 0.01). CONCLUSIONS It can be concluded, that 6 weeks of supplementation and exercise was too short to obtain significant changes in gene expression in leukocytes, but supplementation of 1000 mg vitamin C positively affected IL-6 and IL-10 expression - which are key changes in the adaptation to training. However, changes in body mass, IL1 and CCL2 were positive in CON group. It is possible that Vitamin C during 6 weeks of supplementation could have different effects on the expression of individual genes involved in the immune response. TRIAL REGISTRATION Retrospectively registered.
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Exercise-based cardiac rehabilitation for adults after heart valve surgery.
Abraham, LN, Sibilitz, KL, Berg, SK, Tang, LH, Risom, SS, Lindschou, J, Taylor, RS, Borregaard, B, Zwisler, AD
The Cochrane database of systematic reviews. 2021;(5):CD010876
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Abstract
BACKGROUND The impact of exercise-based cardiac rehabilitation (CR) following heart valve surgery is uncertain. We conducted an update of this systematic review and a meta-analysis to assess randomised controlled trial evidence for the use of exercise-based CR following heart valve surgery. OBJECTIVES To assess the benefits and harms of exercise-based CR compared with no exercise training in adults following heart valve surgery or repair, including both percutaneous and surgical procedures. We considered CR programmes consisting of exercise training with or without another intervention (such as an intervention with a psycho-educational component). SEARCH METHODS We searched the Cochrane Central Register of Clinical Trials (CENTRAL), in the Cochrane Library; MEDLINE (Ovid); Embase (Ovid); the Cumulative Index to Nursing and Allied Health Literature (CINAHL; EBSCO); PsycINFO (Ovid); Latin American Caribbean Health Sciences Literature (LILACS; Bireme); and Conference Proceedings Citation Index-Science (CPCI-S) on the Web of Science (Clarivate Analytics) on 10 January 2020. We searched for ongoing trials from ClinicalTrials.gov, Clinical-trials.com, and the World Health Organization International Clinical Trials Registry Platform on 15 May 2020. SELECTION CRITERIA We included randomised controlled trials that compared exercise-based CR interventions with no exercise training. Trial participants comprised adults aged 18 years or older who had undergone heart valve surgery for heart valve disease (from any cause) and had received heart valve replacement or heart valve repair. Both percutaneous and surgical procedures were included. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data. We assessed the risk of systematic errors ('bias') by evaluating risk domains using the 'Risk of bias' (RoB2) tool. We assessed clinical and statistical heterogeneity. We performed meta-analyses using both fixed-effect and random-effects models. We used the GRADE approach to assess the quality of evidence for primary outcomes (all-cause mortality, all-cause hospitalisation, and health-related quality of life). MAIN RESULTS We included six trials with a total of 364 participants who have had open or percutaneous heart valve surgery. For this updated review, we identified four additional trials (216 participants). One trial had an overall low risk of bias, and we classified the remaining five trials as having some concerns. Follow-up ranged across included trials from 3 to 24 months. Based on data at longest follow-up, a total of nine participants died: 4 CR versus 5 control (relative risk (RR) 0.83, 95% confidence interval (CI) 0.26 to 2.68; 2 trials, 131 participants; GRADE quality of evidence very low). No trials reported on cardiovascular mortality. One trial reported one cardiac-related hospitalisation in the CR group and none in the control group (RR 2.72, 95% CI 0.11 to 65.56; 1 trial, 122 participants; GRADE quality of evidence very low). We are uncertain about health-related quality of life at completion of the intervention in CR compared to control (Short Form (SF)-12/36 mental component: mean difference (MD) 1.28, 95% CI -1.60 to 4.16; 2 trials, 150 participants; GRADE quality of evidence very low; and SF-12/36 physical component: MD 2.99, 95% CI -5.24 to 11.21; 2 trials, 150 participants; GRADE quality of evidence very low), or at longest follow-up (SF-12/36 mental component: MD -1.45, 95% CI -4.70 to 1.80; 2 trials, 139 participants; GRADE quality of evidence very low; and SF-12/36 physical component: MD -0.87, 95% CI -3.57 to 1.83; 2 trials, 139 participants; GRADE quality of evidence very low). AUTHORS' CONCLUSIONS Due to lack of evidence and the very low quality of available evidence, this updated review is uncertain about the impact of exercise-CR in this population in terms of mortality, hospitalisation, and health-related quality of life. High-quality (low risk of bias) evidence on the impact of CR is needed to inform clinical guidelines and routine practice.
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Land-walking vs. water-walking interventions in older adults: Effects on aerobic fitness.
Haynes, A, Naylor, LH, Carter, HH, Spence, AL, Robey, E, Cox, KL, Maslen, BA, Lautenschlager, NT, Ridgers, ND, Green, DJ
Journal of sport and health science. 2020;(3):274-282
Abstract
BACKGROUND Low cardiorespiratory fitness is an independent predictor of all-cause and cardiovascular mortality, and interventions that increase fitness reduce risk. Water-walking decreases musculoskeletal impact and risk of falls in older individuals, but it is unclear whether water-walking improves aerobic fitness in the same way as weight-dependent land-walking. This randomized controlled trial involved 3 intervention groups-a no-exercise control group (CG), a land-walking (LW) group, and a water-walking (WW) group-to investigate the comparative impacts of LW and WW to CG on fitness. METHODS Both exercise groups attended individually tailored, center-based, intensity-matched 3 × weekly sessions for 24 weeks, which progressed to 150 min of exercise per week. This was followed by a 24-week no-intervention period. Maximal graded exercise tests were performed on a treadmill at Weeks 0, 24, and 48. RESULTS Maximal oxygen uptake increased from Week 0 to Week 24 in both exercise groups (0.57 ± 0.62 mL/kg/min, 0.03 ± 0.04 L/min for LW; 0.93 ± 0.75 mL/kg/min, 0.06 ± 0.06 L/min for WW, mean ± SE) compared to the CG (-1.75 ± 0.78 mL/kg/min, -0.16 ± 0.05 L/min) (group × time, p < 0.05). Time to exhaustion increased significantly following LW only (123.4 ± 25.5 s), which was significantly greater (p = 0.001) than the CG (24.3 ± 18.5 s). By Week 48, the training-induced adaptations in the exercise groups returned to near baseline levels. CONCLUSION Our study supports current physical-activity recommendations that 150 min/week of moderate-intensity exercise produces improvements in fitness in previously sedentary older individuals. Also, LW and WW elicit similar improvements in fitness if conducted at the same relative intensities. Exercise-naïve older individuals can benefit from the lower impact forces and decreased risk of falls associated with WW without compromising improvements in cardiorespiratory fitness.
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Energy Balance of Canadian Armed Forces Personnel during an Arctic-Like Field Training Exercise.
Ahmed, M, Mandic, I, Desilets, E, Smith, I, Sullivan-Kwantes, W, Jones, PJ, Goodman, L, Jacobs, I, L'Abbé, M
Nutrients. 2020;(6)
Abstract
Operating in temperature extremes frequently leads to a discrepancy in energy balance. Investigating the effects of operating in extreme cold temperatures on metabolic requirements has not been well described in Canadian Armed Forces (CAF) personnel. The objective was to accurately assess energy deficits using the "gold standard" methodology for measuring energy intake (EI) and energy expenditure (EE). Nutritional intake of a convenience sample of 10 CAF Class A Reservists, completing a basic military qualification (land) course under winter weather conditions, was assessed using the daily measured food intake/food waste collections. EE was measured by the doubly-labelled water method. Average EI was 2377 ± 1144 kcal/day, which was below the EE (4917 ± 693 kcal/day), despite having ~5685 kcal available in the field rations. A significant body weight loss of 2.7% was associated with the average daily energy deficit of 2539 ± 1396 kcal. As a result, participants demonstrated voluntary anorexia. Such results may have important implications for the impairment of performance and health under longer duration operations.
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Immediate post-breakfast physical activity improves interstitial postprandial glycemia: a comparison of different activity-meal timings.
Solomon, TPJ, Tarry, E, Hudson, CO, Fitt, AI, Laye, MJ
Pflugers Archiv : European journal of physiology. 2020;(2):271-280
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Abstract
The optimal timing between meal ingestion and simple physical activity for improving blood glucose control is unknown. This study compared the effects of physical activity on postprandial interstitial glucose responses when the activity was conducted either immediately before, immediately after, or 30 min after breakfast. Forty-eight adults were randomized to three separate physical activity interventions: standing still (for 30 min), walking (for 30 min), and bodyweight exercises (3 sets of 10 squats, 10 push-ups, 10 lunges, 10 sit-ups). In each intervention, 16 participants completed four trials (A to D) during which a 500 kcal mixed nutrient liquid breakfast meal was consumed. Interstitial glucose responses were recorded using continuous glucose monitoring for 2 h after the meal. The activity was completed either after the glucose monitoring period (trial A; control) or immediately before (trial B), immediately after (trial C), or 30 min after (trial D) the breakfast. Mean, coefficient of variance (CV), and area under the curve (AUC) for glucose were calculated and compared between the four trials. Walking and bodyweight exercises immediately after the meal improved mean, CV, and AUC glucose (P ≤ 0.05 vs. control), while standing immediately after the meal only improved AUC glucose (P ≤ 0.05 vs. control) and nearly improved mean glucose (P = 0.06). Mean, CV, and AUC glucose were not affected by standing, walking, or bodyweight exercise conducted immediately before, or 30 min after the meal (all P > 0.05 vs. control). Energy intake (diet records) and energy expenditure (Actigraph) were consistent throughout the studies and did not influence the findings. Low- to moderate-intensity activity should be implemented soon after eating to improve glucose control following breakfast. The type of activity appears less important than the timing. These findings will help optimize exercise-meal timing in general health guidelines. ClinicalTrials.gov Identifier: NCT03730727.
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Nutritional Strategies to Optimize Performanceand Recovery in Rowing Athletes.
Kim, J, Kim, EK
Nutrients. 2020;(6)
Abstract
Rowing is a high-intensity sport requiring a high level of aerobic and anaerobic capacity. Although good nutrition is essential for successful performance in a rowing competition, its significance is not sufficiently established. This review aimed to provide nutritional strategies to optimize performance and recovery in rowing athletes based on a literature review. Following the guidelines given in the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), we performed web searches using online databases (Pubmed, Web of Science, Wiley Online Library, ACS Publications, and SciFinder). Typically, a rowing competition involves a 6-8-min high-intensity exercise on a 2000-m course. The energy required for the exercise is supplied by muscle-stored glycogens, which are derived from carbohydrates. Therefore, rowing athletes can plan their carbohydrate consumption based on the intensity, duration, and type of training they undergo. For effective and safe performance enhancement, rowing athletes can take supplements such as β-alanine, caffeine, β-hydroxy-β-methylbutyric acid (HMB), and beetroot juice (nitrate). An athlete may consume carbohydrate-rich foods or use a carbohydrate mouth rinse. Recovery nutrition is also very important to minimize the risk of injury or unexplained underperformance syndrome (UUPS) from overuse. It must take into account refueling (carbohydrate), rehydration (fluid), and repair (protein). As lightweight rowing athletes often attempt acute weight loss by limiting food and fluid intake to qualify for a competition, they require personalized nutritional strategies and plans based on factors such as their goals and environment. Training and competition performance can be maximized by including nutritional strategies in training plans.
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Muscle protein breakdown is impaired during immobilization compared to during a subsequent retraining period in older men: no effect of anti-inflammatory medication.
Dideriksen, K, Reitelseder, S, Agergaard, J, Boesen, AP, Aas, SN, Raastad, T, Holm, L
Pflugers Archiv : European journal of physiology. 2020;(2):281-292
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Abstract
Muscle inactivity reduces muscle protein synthesis (MPS), whereas a subsequent period of rehabilitation resistance training (retraining) increases MPS. However, less is known regarding muscle protein breakdown (MPB) during such conditions. Furthermore, nonsteroidal anti-inflammatory drugs (NSAIDs) may have a dampening effect on MPB during periods of inactivity in older individuals. Thus, we measured the average MPB, by use of the deuterated water methodology, during an immobilization period and a subsequent retraining period in older individuals with and without NSAID treatment. Eighteen men (60-80 years: range) were randomly assigned to ibuprofen (1200 mg/d, Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 weeks and retrained for 2 weeks, and 2 × 20 g of whey protein was ingested daily during both periods. Besides MPB, the protein expression of different muscle degradation signaling molecules was investigated. MPB was lower during immobilization compared to retraining (p < 0.01). NSAID treatment did not affect the MPB rate during immobilization or retraining (p > 0.05). The protein expression of muscle degradation signaling molecules changed during the study intervention but were unaffected by NSAID treatment. The finding that MPB was lower during immobilization than during retraining indicates that an increased MPB may play an important role in the muscle protein remodeling processes taking place within the initial retraining period. Moreover, NSAID treatment did not significantly influence the MPB rate during 2 weeks of lower limb immobilization or during 2 weeks of subsequent retraining in older individuals.
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A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions Are Needed.
Wilund, KR, Viana, JL, Perez, LM
Exercise and sport sciences reviews. 2020;(1):28-39
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Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity.