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1.
Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers.
Burke, LM, Hall, R, Heikura, IA, Ross, ML, Tee, N, Kent, GL, Whitfield, J, Forbes, SF, Sharma, AP, Jones, AM, et al
Nutrients. 2021;(8)
Abstract
Given the importance of exercise economy to endurance performance, we implemented two strategies purported to reduce the oxygen cost of exercise within a 4 week training camp in 21 elite male race walkers. Fourteen athletes undertook a crossover investigation with beetroot juice (BRJ) or placebo (PLA) [2 d preload, 2 h pre-exercise + 35 min during exercise] during a 26 km race walking at speeds simulating competitive events. Separately, 19 athletes undertook a parallel group investigation of a multi-pronged strategy (MAX; n = 9) involving chronic (2 w high carbohydrate [CHO] diet + gut training) and acute (CHO loading + 90 g/h CHO during exercise) strategies to promote endogenous and exogenous CHO availability, compared with strategies reflecting lower ranges of current guidelines (CON; n = 10). There were no differences between BRJ and PLA trials for rates of CHO (p = 0.203) or fat (p = 0.818) oxidation or oxygen consumption (p = 0.090). Compared with CON, MAX was associated with higher rates of CHO oxidation during exercise, with increased exogenous CHO use (CON; peak = ~0.45 g/min; MAX: peak = ~1.45 g/min, p < 0.001). High rates of exogenous CHO use were achieved prior to gut training, without further improvement, suggesting that elite athletes already optimise intestinal CHO absorption via habitual practices. No differences in exercise economy were detected despite small differences in substrate use. Future studies should investigate the impact of these strategies on sub-elite athletes' economy as well as the performance effects in elite groups.
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Cardiovascular Rehabilitation Increases Walking Distance in Patients With Intermittent Claudication. Results of the CIPIC Rehab Study: A Randomised Controlled Trial.
Siercke, M, Jørgensen, LP, Missel, M, Thygesen, LC, Møller, SP, Sillesen, H, Berg, SK
European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. 2021;(5):768-776
Abstract
OBJECTIVE To examine whether a cardiac rehabilitation programme in a community based setting for patients with intermittent claudication (IC) affects walking ability, quality of life, and changes in health behaviour. The trial investigated a cross sector cardiovascular rehabilitation programme compared with usual care for patients having non-operative management. METHODS The trial allocated 118 patients, with 1:1 individual randomisation to either an intervention or control group. Data were collected at a department of vascular surgery and at a healthcare centre in Denmark. The rehabilitation intervention consisted of usual care plus 12 weeks of exercise training, pedometer, health education, and text messages. The primary outcome was maximum walking distance at six months measured by treadmill walking test. The secondary outcomes were maximum walking distance at 12 months and pain free walking distance measured by treadmill walking test, healthy diet, level of physical activity, and quality of life (QoL) at six and 12 months. RESULTS In the intervention group, 46 participants were analysed, with 47 in the control group. Following three months of rehabilitation, a 37% difference (95% CI 1.10 - 1.70; p = .005) was found between groups in maximum walking distance at six and 12 months, in favour of the intervention group. The same positive effect was found in physical activity, QoL, and healthy diet, but was not statistically significant in pain free walking distance and smoking. CONCLUSION A specialised community based cardiac rehabilitation programme for patients with IC showed statistically and clinically significant effects on maximum walking distance, physical activity, quality of life, and healthy diet, but not on pain free walking distance and smoking, compared with usual care without rehabilitation.
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Physical activity and the risk of heart failure: a systematic review and dose-response meta-analysis of prospective studies.
Aune, D, Schlesinger, S, Leitzmann, MF, Tonstad, S, Norat, T, Riboli, E, Vatten, LJ
European journal of epidemiology. 2021;(4):367-381
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Abstract
Although physical activity is an established protective factor for cardiovascular diseases such as ischemic heart disease and stroke, less is known with regard to the association between specific domains of physical activity and heart failure, as well as the association between cardiorespiratory fitness and heart failure. We conducted a systematic review and meta-analysis of prospective observational studies to clarify the relations of total physical activity, domains of physical activity and cardiorespiratory fitness to risk of heart failure. PubMed and Embase databases were searched up to January 14th, 2020. Summary relative risks (RRs) were calculated using random effects models. Twenty-nine prospective studies (36 publications) were included in the review. The summary RRs for high versus low levels were 0.77 (95% CI 0.70-0.85, I2 = 49%, n = 7) for total physical activity, 0.74 (95% CI 0.68-0.81, I2 = 88.1%, n = 16) for leisure-time activity, 0.66 (95% CI 0.59-0.74, I2 = 0%, n = 2) for vigorous activity, 0.81 (95% CI 0.69-0.94, I2 = 86%, n = 3) for walking and bicycling combined, 0.90 (95% CI 0.86-0.95, I2 = 0%, n = 3) for occupational activity, and 0.31 (95% CI 0.19-0.49, I2 = 96%, n = 6) for cardiorespiratory fitness. In dose-response analyses, the summary RRs were 0.89 (95% CI 0.83-0.95, I2 = 67%, n = 4) per 20 MET-hours per day of total activity and 0.71 (95% CI 0.65-0.78, I2 = 85%, n = 11) per 20 MET-hours per week of leisure-time activity. Nonlinear associations were observed in both analyses with a flattening of the dose-response curve at 15-20 MET-hours/week for leisure-time activity. These findings suggest that high levels of total physical activity, leisure-time activity, vigorous activity, occupational activity, walking and bicycling combined and cardiorespiratory fitness are associated with reduced risk of developing heart failure.
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Effects of interrupting sitting with different activity bouts on postprandial lipemia: A randomized crossover trial.
Ma, SX, Zhu, Z, Cao, ZB
Scandinavian journal of medicine & science in sports. 2021;(3):633-642
Abstract
To determine whether interrupting prolonged sitting with three different activity breaks has both acute and chronic effects on postprandial lipid metabolism immediately after the activity-break period and on the following day, this study is a secondary analysis of an experimental research, which included 16 sedentary healthy adults (7 men, 24 ± 3 years, BMI 22.2 ± 2.3 kg/m2 ) who completed four 26-h laboratory trials. Participants spent 22.5 hours in a whole room calorimeter for testing energy expenditure (EE), including a 9-h activity-break period: (a) 9-h prolonged sitting (SIT); (b) 3 minutes of brisk walking (60% VO2max ) in between every 30-min sitting bout (WALK3), (c) 5 minutes every 45-min (WALK5), and (d) 8 minutes every 60-min (WALK8). Total area under the curve (tAUC) and incremental AUC (iAUC) for 2-h postprandial serum triglyceride (TG) levels and non-esterified fatty acid (NEFA) levels were examined immediately after the 9-h trial (post-dinner) and the next morning (post-breakfast). WALK8 reduced the post-breakfast TG tAUC by 11% (P = .041) relative to SIT, and the effect was attenuated after adjustment for EE. The tAUC and iAUC indicated no significant treatment effects on post-dinner TG and NEFA, and post-breakfast NEFA in any of the activity-break trials. EE was positively associated with the post-breakfast NEFA iAUC (unstandardized β = 0.17 µmol/L/MJ [0.05-0.28], P = .006). There was a chronic effect of interrupting sitting with short bouts (8 minutes) of brisk walking every 60 minutes on postprandial lipemia the following morning after intervention, and higher activity bout-induced EE may be more effective in sedentary, healthy adults.
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Anabolic Bone Stimulus Requires a Pre-Exercise Meal and 45-Minute Walking Impulse of Suprathreshold Speed-Enhanced Momentum to Prevent or Mitigate Postmenopausal Osteoporosis within Circadian Constraints.
Zheng, Q, Kernozek, T, Daoud-Gray, A, Borer, KT
Nutrients. 2021;(11)
Abstract
Osteoporosis currently afflicts 8 million postmenopausal women in the US, increasing the risk of bone fractures and morbidity, and reducing overall quality of life. We sought to define moderate exercise protocols that can prevent postmenopausal osteoporosis. Our previous findings singled out higher walking speed and pre-exercise meals as necessary for suppression of bone resorption and increasing of markers of bone formation. Since both studies were amenable to alternate biomechanical, nutritional, and circadian interpretations, we sought to determine the relative importance of higher speed, momentum, speed-enhanced load, duration of impulse, and meal timing on osteogenic response. We hypothesized that: (1) 20 min of exercise one hour after eating is sufficient to suppress bone resorption as much as a 40-min impulse and that two 20 min exercise bouts separated by 7 h would double the anabolic effect; (2) early morning exercise performed after eating will be as effective as mid-day exercise for anabolic outcome; and (3) the 08:00 h 40-min. exercise uphill would be as osteogenic as the 40-min exercise downhill. Healthy postmenopausal women, 8 each, were assigned to a no-exercise condition (SED) or to 40- or 20-min exercise bouts, spaced 7 h apart, for walking uphill (40 Up and 20 Up) or downhill (40 Down and 20 Down) to produce differences in biomechanical variables. Exercise was initiated at 08:00 h one hour after eating in 40-min groups, and also 7 h later, two hours after the midday meal, in 20-min groups. Measurements were made of CICP (c-terminal peptide of type I collagen), osteocalcin (OC), and bone-specific alkaline phosphatase (BALP), markers of bone formation, and of the bone resorptive marker CTX (c-terminal telopeptide of type 1 collagen). The osteogenic ratios CICP/CTX, OC/CTX, and BALP/CTX were calculated. Only the 40-min downhill exercise of suprathreshold speed-enhanced momentum, increased the three osteogenic ratios, demonstrating the necessity of a 40-min, and inadequacy of a 20-min, exercise impulse. The failure of anabolic outcome in 40-min uphill exercise was attributed to a sustained elevation of PTH concentration, as its high morning elevation enhances the CTX circadian rhythm. We conclude that postmenopausal osteoporosis can be prevented or mitigated in sedentary women by 45 min of morning exercise of suprathreshold speed-enhanced increased momentum performed shortly after a meal while walking on level ground, or by 40-min downhill, but not 40-min uphill, exercise to avoid circadian PTH oversecretion. The principal stimulus for the anabolic effect is exercise, but the prerequisite for a pre-exercise meal demonstrates the requirement for nutrient facilitation.
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Safety, Patient-Reported Well-Being, and Physician-Reported Assessment of Walking Ability in Patients with Multiple Sclerosis for Prolonged-Release Fampridine Treatment in Routine Clinical Practice: Results of the LIBERATE Study.
Castelnovo, G, Gerlach, O, Freedman, MS, Bergmann, A, Sinay, V, Castillo-Triviño, T, Kong, G, Koster, T, Williams, H, Gafson, AR, et al
CNS drugs. 2021;(9):1009-1022
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Abstract
BACKGROUND Prolonged-release fampridine (PR-FAM) 10-mg tablet twice daily is the only approved pharmacological treatment for improvement of walking ability in adults with multiple sclerosis (MS). LIBERATE assessed the safety/effectiveness of PR-FAM in the real-world. OBJECTIVES The aim of this study was to collect additional safety data, including the incidence rate of seizures and other adverse events (AEs) of interest, from patients with MS taking PR-FAM in routine clinical practice (including patients aged ≥ 65 years and those with pre-existing cardiovascular risk factors). Other objectives included change over time in patient-reported evaluation of physical and psychological impact of MS while taking PR-FAM, and change over time in physician-reported assessment of walking ability in MS patients taking PR-FAM. METHODS Patients with MS newly prescribed PR-FAM were recruited (201 sites, 13 countries). Demographic/safety data were collected at enrolment through 12 months. Physician-rated Clinical Global Impression of Improvement (CGI-I) scores for walking ability, and Multiple Sclerosis Impact Scale-29 (MSIS-29) were assessed. RESULTS Safety analysis included 4646 patients with 3534.8 patient-years of exposure; median (range) age, 52.6 (21-85) years, 87.3% < 65 years, and 65.7% women. Treatment-emergent AEs (TEAEs) were reported in 2448 (52.7%) patients, and serious TEAEs were reported in 279 (6.0%) patients, of whom 37 (< 1%) experienced treatment-emergent serious AEs (TESAEs) considered related to PR-FAM. AEs of special interest (AESI) occurred in 1799 (38.7%) patients, and serious AESI in 128 (2.8%) patients. Seventeen (< 1%) patients experienced actual events of seizure. Overall, 1158 (24.9%) patients discontinued treatment due to lack of efficacy. At 12 months, a greater proportion of patients on-treatment had improvement from baseline in CGI-I for walking ability versus those who discontinued (61% vs. 11%; p < 0.001). MSIS-29 physical impact score improved significantly for patients on-treatment for 12 months versus those who discontinued (mean change, baseline to 12 months: - 9.99 vs. - 0.34 points; p < 0.001). Results were similar for MSIS-29 psychological impact. CONCLUSION No new safety concerns were identified in this real-world study, suggesting that routine risk-minimization measures are effective. CGI-I and MSIS-29 scores after 12 months treatment with PR-FAM treatment show clinical benefits consistent with those previously reported. TRIAL REGISTRATION ClinicalTrials.gov: NCT01480063.
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Interrupting Prolonged Sitting Reduces Postprandial Glucose Concentration in Young Men With Central Obesity.
Wongpipit, W, Zhang, X, Miyashita, M, Wong, SH
The Journal of clinical endocrinology and metabolism. 2021;(2):e791-e802
Abstract
CONTEXT Prolonged sitting elevates postprandial metabolic markers, resulting in increased risks of cardiovascular diseases and type 2 diabetes. Interrupting prolonged sitting may reduce these risks. However, more information is needed to understand the patterns of interrupting prolonged sitting to obtain metabolic health benefits. OBJECTIVE This study examined the effects of interrupting prolonged sitting with different intensities and durations of walking with an equivalent energy expenditure on postprandial metabolic responses in young Chinese men with central obesity. DESIGN A randomized crossover experimental trial was conducted. SETTING Participants underwent three 6-hour experiments with a 7-day washout period between each experiment: prolonged sitting, 3 min of light-intensity walking every 30 minutes, and 1.5 minutes of moderate-intensity walking every 30 minutes. PARTICIPANTS AND SAMPLES Baseline (fasting) and 6-hour postprandial metabolic glucose and lipid levels were analyzed among 18 young Chinese men with central obesity. MAIN OUTCOME MEASURES Generalized estimating equations (adjusted for the potential confounders explaining residual outcome variance (body mass index) and age), trial order, preprandial values, and lead-in activity) were used, and the incremental areas under the curve (iAUC) of each outcome were compared between prolonged sitting and interrupted prolonged sitting conditions. RESULTS Compared with prolonged sitting, both interrupting prolonged sitting conditions reduced the iAUCs for glucose (P < .05) but not insulin, C-peptide, triglycerides, or nonesterified fatty acids. CONCLUSIONS Both conditions of interrupted prolonged sitting reduced postprandial glucose concentrations in young Chinese men with central obesity when the energy expenditure was equivalent.
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White matter plasticity in healthy older adults: The effects of aerobic exercise.
Mendez Colmenares, A, Voss, MW, Fanning, J, Salerno, EA, Gothe, NP, Thomas, ML, McAuley, E, Kramer, AF, Burzynska, AZ
NeuroImage. 2021;:118305
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Abstract
White matter deterioration is associated with cognitive impairment in healthy aging and Alzheimer's disease. It is critical to identify interventions that can slow down white matter deterioration. So far, clinical trials have failed to demonstrate the benefits of aerobic exercise on the adult white matter using diffusion Magnetic Resonance Imaging. Here, we report the effects of a 6-month aerobic walking and dance interventions (clinical trial NCT01472744) on white matter integrity in healthy older adults (n = 180, 60-79 years) measured by changes in the ratio of calibrated T1- to T2-weighted images (T1w/T2w). Specifically, the aerobic walking and social dance interventions resulted in positive changes in the T1w/T2w signal in late-myelinating regions, as compared to widespread decreases in the T1w/T2w signal in the active control. Notably, in the aerobic walking group, positive change in the T1w/T2w signal correlated with improved episodic memory performance. Lastly, intervention-induced increases in cardiorespiratory fitness did not correlate with change in the T1w/T2w signal. Together, our findings suggest that white matter regions that are vulnerable to aging retain some degree of plasticity that can be induced by aerobic exercise training. In addition, we provided evidence that the T1w/T2w signal may be a useful and broadly accessible measure for studying short-term within-person plasticity and deterioration in the adult human white matter.
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Effect of a multicomponent nutritional supplement on functional outcomes for Duchenne muscular dystrophy: A randomized controlled trial.
Davidson, ZE, Hughes, I, Ryan, MM, Kornberg, AJ, Cairns, AG, Jones, K, Hutchence, M, Sampaio, H, Morrison, M, Truby, H
Clinical nutrition (Edinburgh, Scotland). 2021;(7):4702-4711
Abstract
BACKGROUND & AIMS Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular condition causing progressive muscle weakness and premature death. Whilst effective treatments such as gene therapy are developed, families often seek complementary therapies such as nutrition supplements to help their son maintain function; however, there is limited evidence supporting the use of nutritional supplements in DMD. This study aimed to compare the effect of a Standard nutritional supplement with an Enhanced nutritional supplement combining three nutriceuticals on functional outcomes in ambulatory boys with Duchenne muscular dystrophy (DMD). DESIGN A 50-week double blinded, randomized, controlled crossover trial was conducted in four Australian neuromuscular centres. Primary outcome measures were 6-min walk distance (6MWD) and community ambulation (StepWatch™ Activity Monitoring). Secondary outcome measures included body composition and quality of life. Serum 25-hydroxyvitamin D was measured. RESULTS Twenty-seven boys completed the intervention. Traditional crossover analysis demonstrated the Enhanced supplement compared to the Standard supplement was associated with a difference of +12 (95% CI: -16, 40) metres in 6MWD, +0.5 (95% CI: -53, 54) inactive minutes per day and -95 (95% CI: -887, 696) steps per day. A mixed effect model indicated a potentially clinically important effect of the Enhanced supplement on the 6MWD of +31 (95% CI: -19, 81) metres. Mean serum 25 hydroxyvitamin D levels at week 50 was 94 (95% CI: 84, 104) nmol/L. There was no observable effect of either supplement regime on body composition or quality of life. CONCLUSIONS Whilst a positive effect of the Enhanced supplement on functional outcomes was observed, this finding was inconclusive due to the small sample size. The results do not support the use of combined nutritional supplements to improve body composition or quality of life in DMD. A dose of 2000 IU vitamin D was an adequate dose to raise serum 25-hydroxyvitamin D over 50 weeks. CLINICAL TRIAL REGISTRY Registry #: ACTRN12610000462088, http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12610000462088.
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Cocoa might improve walking performance in PAD.
Huynh, K
Nature reviews. Cardiology. 2020;(5):266