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ɑ-Lactalbumin Improves Sleep and Recovery after Simulated Evening Competition in Female Athletes.
Miles, KH, Clark, B, Fowler, PM, Gratwicke, MJ, Martin, K, Welvaert, M, Miller, J, Pumpa, KL
Medicine and science in sports and exercise. 2021;(12):2618-2627
Abstract
PURPOSE This study aimed to determine the efficacy of α-lactalbumin (A-LAC) supplementation for improving sleep and performance recovery after simulated evening competition in female athletes. METHODS Sixteen trained women (mean ± SD: age, 27 ± 7 yr; mass, 62 ± 10 kg; stature, 167 ± 8 cm) participated in this randomized double-blind three-arm crossover study. Participants completed a simulated evening competition before consuming either an A-LAC whey protein, whey protein placebo (PLA), or water control (CON) beverage. Sleep was monitored via polysomnography, and participants completed a series of physical, cognitive, and perceptual assessments before, and 14 and 24 h after simulated competition. RESULTS Non-rapid eye movement stage 2 sleep increased after competition in A-LAC (pre, 199 ± 44 min; post, 212 ± 37 min) but decreased in CON (pre, 228 ± 43 min; post, 195 ± 40 min) and PLA (pre, 224 ± 25 min; post, 211 ± 35 min; P = 0.012). In addition, Yo-Yo Intermittent Recovery Test Level 1 distance improved over time in A-LAC (baseline, 664 ± 332 m; 14 h post, 667 ± 326 m; 24 h post, 781 ± 427 m) compared with CON (baseline, 741 ± 366 m; 14 h post, 648 ± 351 m; 24 h post, 720 ± 407 m) and PLA (baseline, 763 ± 394 m; 14 h post, 636 ± 366 m; 24 h post, 720 ± 396 m; P < 0.001). CONCLUSIONS The findings indicate that A-LAC supplementation may be useful for retaining some sleep characteristics after evening competition, leading to improved physical performance in female athletes.
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Crisis of confidence averted: Impairment of exercise economy and performance in elite race walkers by ketogenic low carbohydrate, high fat (LCHF) diet is reproducible.
Burke, LM, Sharma, AP, Heikura, IA, Forbes, SF, Holloway, M, McKay, AKA, Bone, JL, Leckey, JJ, Welvaert, M, Ross, ML
PloS one. 2020;(6):e0234027
Abstract
INTRODUCTION We repeated our study of intensified training on a ketogenic low-carbohydrate (CHO), high-fat diet (LCHF) in world-class endurance athletes, with further investigation of a "carryover" effect on performance after restoring CHO availability in comparison to high or periodised CHO diets. METHODS After Baseline testing (10,000 m IAAF-sanctioned race, aerobic capacity and submaximal walking economy) elite male and female race walkers undertook 25 d supervised training and repeat testing (Adapt) on energy-matched diets: High CHO availability (8.6 g∙kg-1∙d-1 CHO, 2.1 g∙kg-1∙d-1 protein; 1.2 g∙kg-1∙d-1 fat) including CHO before/during/after workouts (HCHO, n = 8): similar macronutrient intake periodised within/between days to manipulate low and high CHO availability at various workouts (PCHO, n = 8); and LCHF (<50 g∙d-1 CHO; 78% energy as fat; 2.1 g∙kg-1∙d-1 protein; n = 10). After Adapt, all athletes resumed HCHO for 2.5 wk before a cohort (n = 19) completed a 20 km race. RESULTS All groups increased VO2peak (ml∙kg-1∙min-1) at Adapt (p = 0.02, 95%CI: [0.35-2.74]). LCHF markedly increased whole-body fat oxidation (from 0.6 g∙min-1 to 1.3 g∙min-1), but also the oxygen cost of walking at race-relevant velocities. Differences in 10,000 m performance were clear and meaningful: HCHO improved by 4.8% or 134 s (95% CI: [207 to 62 s]; p < 0.001), with a trend for a faster time (2.2%, 61 s [-18 to +144 s]; p = 0.09) in PCHO. LCHF were slower by 2.3%, -86 s ([-18 to -144 s]; p < 0.001), with no evidence of superior "rebound" performance over 20 km after 2.5 wk of HCHO restoration and taper. CONCLUSION Our previous findings of impaired exercise economy and performance of sustained high-intensity race walking following keto-adaptation in elite competitors were repeated. Furthermore, there was no detectable benefit from undertaking an LCHF intervention as a periodised strategy before a 2.5-wk race preparation/taper with high CHO availability. TRIAL REGISTRATION Australia New Zealand Clinical Trial Registry: ACTRN12619000794101.
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The impact of high-intensity interval training exercise on breast cancer survivors: a pilot study to explore fitness, cardiac regulation and biomarkers of the stress systems.
Toohey, K, Pumpa, K, McKune, A, Cooke, J, Welvaert, M, Northey, J, Quinlan, C, Semple, S
BMC cancer. 2020;(1):787
Abstract
BACKGROUND Cardiovascular disease (CVD) remains the largest cause of death in breast cancer survivors. The aim of this study was to explore the impact of exercise intensity on aerobic fitness and autonomic cardiac regulation (heart rate variability (HRV)) and salivary biomarkers of the stress systems (HPA-axis, cortisol; sympathetic nervous system, α-amylase) and mucosal immunity (secretory(s)-IgA), markers of increased risk of CVD in breast cancer survivors. METHODS Participants were randomly assigned to; 1) high intensity interval training (HIIT); 2) moderate-intensity, continuous aerobic training (CMIT); or 3) a wait-list control (CON) for a 12-week (36 session) stationary cycling intervention. Cardiorespiratory fitness (VO2peak), resting HRV and salivary biomarkers were measured at baseline 2-4 d pre-intervention and 2-4 d post the last exercise session. RESULTS Seventeen participants were included in this study (62 ± 8 years, HIIT; n = 6, CMIT; n = 5, CON; n = 6). A significant improvement (p ≤ 0.05) was observed for VO2peak in the HIIT group; 19.3% (B = 3.98, 95%CI = [1.89; 4.02]) and a non-significant increase in the CMIT group; 5.6% (B = 1.96, 95%CI = [- 0.11; 4.03]), compared with a 2.6% (B = - 0.64, 95%CI = [- 2.10; 0.82]) decrease in the CON group. Post intervention improvements in HRV markers of vagal activity (log (ln)LF/HF, LnRMSSD) and sympathetic nervous system (α-amylase waking response) occurred for individuals exhibiting outlying (> 95% CI) levels at baseline compared to general population. CONCLUSION High intensity interval training improved cardiovascular fitness in breast cancer survivors and improved cardiac regulation, and sympathetic nervous system (stress) responses in some individuals. High-intensity interval training was safe and effective for breast cancer survivors to participate in with promising results as a time efficient intensity to improve physical health and stress, reducing CVD risk. TRIAL REGISTRATION This pilot study was retrospectively registered through the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000684921 .
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Adding Telephone and Text Support to an Obesity Management Program Improves Behavioral Adherence and Clinical Outcomes. A Randomized Controlled Crossover Trial.
Lewis, E, Huang, HC, Hassmén, P, Welvaert, M, Pumpa, KL
International journal of behavioral medicine. 2019;(6):580-590
Abstract
BACKGROUND Behavioral treatment strategies improve adherence to lifestyle intervention for adults with obesity, but can be time and resource intensive when delivered via traditional face-to-face care. This study aimed to investigate the efficacy and optimal timing of using telephone calls and text message as adjunctive tools to support a community-based obesity management program. METHOD This 8-month randomized controlled crossover trial recruited 61 adults with class III obesity (BMI > 40 kg/m2) enrolled in a publicly funded obesity management service (OMS). Participants were randomly assigned to receive telephone and text message support in addition to standard OMS care, or standard OMS care alone. After 4 months, participants crossed over to the alternative sequence. The technological support was based on self-determination theory. Outcome measures included diet, physical activity, anthropometry, self-efficacy, and treatment self-regulation. RESULTS Telephone and text message support improved lifestyle intervention adherence and clinical outcomes when compared with standard care. Participants who received the intervention in the first 4-month period lost 4.87 kg, compared with no weight loss (+ 0.38 kg) in the standard care only group. There was no evidence to indicate an optimal timing of the intervention, with both groups achieving significant results by the end of the intervention. CONCLUSION These results suggest a high degree of promise for the incorporation of telephone and text message support into community-based obesity management services. The findings have the potential to improve existing practices and reduce the burden on the health care system by demonstrating a resource-effective improvement to obesity management service delivery.
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Chronic Ketogenic Low Carbohydrate High Fat Diet Has Minimal Effects on Acid-Base Status in Elite Athletes.
Carr, AJ, Sharma, AP, Ross, ML, Welvaert, M, Slater, GJ, Burke, LM
Nutrients. 2018;10(2)
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The low-fat, high-carbohydrate ketogenic diet has recently been applied to the context of elite athletes to observe potential impact on performance and metabolism during exercise and rest. The aim to this study was to assess the effect of a long-term ketogenic diet on the acid-base status in elite athletes, particularly investigating whether sustained diet change caused alterations in overall acid production. Twenty-one athletes were assigned to a high carbohydrate diet, low carbohydrate diet and periodised carbohydrate availability diet for three sustained weeks. Acid-base balance was measured via blood samples at baseline and post-intervention. The main finding of this study was that a sustained ketogenic diet had no influence of acid-base status. Based on these results, the authors conclude that long-term manipulation of macronutrient intake is unlikely to influence acid-base status in this population. It is also noted that elite athletes may have an increased buffering capacity compared with the general population, and that further research should be done in different participant populations.
Abstract
Although short (up to 3 days) exposure to major shifts in macronutrient intake appears to alter acid-base status, the effects of sustained (>1 week) interventions in elite athletes has not been determined. Using a non-randomized, parallel design, we examined the effect of adaptations to 21 days of a ketogenic low carbohydrate high fat (LCHF) or periodized carbohydrate (PCHO) diet on pre- and post-exercise blood pH, and concentrations of bicarbonate (HCO₃-) and lactate (La-) in comparison to a high carbohydrate (HCHO) control. Twenty-four (17 male and 7 female) elite-level race walkers completed 21 days of either LCHF (n = 9), PCHO (n = 7), or HCHO (n = 8) under controlled diet and training conditions. At baseline and post-intervention, blood pH, blood [HCO₃-], and blood [La-] were measured before and after a graded exercise test. Net endogenous acid production (NEAP) over the previous 48-72 h was also calculated from monitored dietary intake. LCHF was not associated with significant differences in blood pH, [HCO₃-], or [La-], compared with the HCHO diet pre- or post-exercise, despite a significantly higher NEAP (mEq·day-1) (95% CI = [10.44; 36.04]). Our results indicate that chronic dietary interventions are unlikely to influence acid-base status in elite athletes, which may be due to pre-existing training adaptations, such as an enhanced buffering capacity, or the actions of respiratory and renal pathways, which have a greater influence on regulation of acid-base status than nutritional intake.
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Behavioural treatment strategies improve adherence to lifestyle intervention programmes in adults with obesity: a systematic review and meta-analysis.
Burgess, E, Hassmén, P, Welvaert, M, Pumpa, KL
Clinical obesity. 2017;(2):105-114
Abstract
Poor adherence to lifestyle intervention remains a key factor hindering treatment effectiveness and health outcomes for adults with obesity. The aim of this systematic review and meta-analysis is to determine if behavioural treatment strategies (e.g. goal setting, motivational interviewing, relapse prevention, cognitive restructuring etc.) improve adherence to lifestyle intervention programmes in adults with obesity. Randomized controlled trials that investigated the use of behavioural treatment strategies in obesity management were identified by systematically reviewing the literature within Medline, PsycINFO, CINAHL, SPORTDiscus and Web of Science from their inception to August 2016. This meta-analysis shows that behavioural treatment interventions have a significant positive effect on session attendance (percentage) and physical activity (total min/week) in adults with obesity (M = 17.63 (95% confidence interval (CI) = 10.77, 24.50), z =5.0337, P < 0.0001 and M = 105.98 (95% CI = 58.64, 153.32), z =4.3878, P < 0.0001, respectively). This meta-analysis of randomized controlled trials provides evidence that behavioural treatment strategies improve adherence to lifestyle intervention programmes in adults with obesity. These strategies should be routinely incorporated into lifestyle intervention, obesity management and weight loss programmes with the aim of improving engagement and adherence. If adherence were improved, treatment effectiveness, health outcomes and the ultimate burden of chronic disease could also be improved.