The metabolic interplay between dietary carbohydrate and exercise and its role in acute appetite regulation in males: a randomized controlled study.

An understanding of the metabolic determinants of postexercise appetite regulation would facilitate development of adjunctive therapeutics to suppress compensatory eating behaviours and improve the efficacy of exercise as a weight-loss treatment. Metabolic responses to acute exercise are, however, dependent on pre-exercise nutritional practices, including carbohydrate intake. We therefore aimed to determine the interactive effects of dietary carbohydrate and exercise on plasma hormonal and metabolite responses and explore mediators of exercise-induced changes in appetite regulation across nutritional states. In this randomized crossover study, participants completed four 120 min visits: (i) control (water) followed by rest; (ii) control followed by exercise (30 min at ∼75% of maximal oxygen uptake); (iii) carbohydrate (75 g maltodextrin) followed by rest; and (iv) carbohydrate followed by exercise. An ad libitum meal was provided at the end of each 120 min visit, with blood sample collection and appetite assessment performed at predefined intervals. We found that dietary carbohydrate and exercise exerted independent effects on the hormones glucagon-like peptide 1 (carbohydrate, 16.8 pmol/L; exercise, 7.4 pmol/L), ghrelin (carbohydrate, -48.8 pmol/L; exercise: -22.7 pmol/L) and glucagon (carbohydrate, 9.8 ng/L; exercise, 8.2 ng/L) that were linked to the generation of distinct plasma 1 H nuclear magnetic resonance metabolic phenotypes. These metabolic responses were associated with changes in appetite and energy intake, and plasma acetate and succinate were subsequently identified as potential novel mediators of exercise-induced appetite and energy intake responses. In summary, dietary carbohydrate and exercise independently influence gastrointestinal hormones associated with appetite regulation. Future work is warranted to probe the mechanistic importance of plasma acetate and succinate in postexercise appetite regulation. KEY POINTS: Carbohydrate and exercise independently influence key appetite-regulating hormones. Temporal changes in postexercise appetite are linked to acetate, lactate and peptide YY. Postexercise energy intake is associated with glucagon-like peptide 1 and succinate levels.

Effects of exercise training on metabolic syndrome risk factors in post-menopausal women - A systematic review and meta-analysis of randomised controlled trials.

BACKGROUND & AIMS: Alterations in the hormonal profiles as women transition to the menopause predisposes individuals to the metabolic syndrome (MetS). In post-menopausal women, this can be exacerbated by sedentary behaviour and physical inactivity. Physical activity can convey many health benefits including improvement in MetS risk factors. However, it remains to be elucidated how differing exercise intensities and its mode of delivery can ameliorate MetS risk factors and resultant progression amongst post-menopausal women. The purpose of this systematic review and meta-analysis was to investigate the effects and efficacy of exercise training on MetS risk factors in post-menopausal women. METHODS: Database searches using PubMed, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials were conducted from inception to December 2021 for randomised controlled studies (RCTs) investigating exercise training (>8 weeks) in at least one of the MetS risk factors in post-menopausal women. Utilising the random-effects model, appropriate standardised mean differences (SMD) or mean differences (MD) with 95% confidence interval (CI) for each MetS risk factor were used to calculate the overall effect size between the exercise and control groups. Sub-group analyses were performed for exercise intensity, modality, and duration for each risk factor. Meta-regression was performed for categorical (health status) and continuous (body mass index) covariates. RESULTS: 39 RCTs (40 studies) involving 2132 participants were identified as eligible. Overall, the meta-analysis shows that exercise training significantly improved all MetS risk factors: waist circumference (WC) [MD: -2.61 cm; 95% CI: -3.39 to -1.86 cm; p < 0.001; 21 studies]; triglycerides (TG) [SMD: -0.40 mmol/L; 95% CI: -0.71 to -0.09 mmol/L; p = 0.01; 25 studies]; high-density lipoprotein (HDL) [SMD: 0.84 mmol/L (95% CI: 0.41-1.27 mmol/L; p < 0.001; 26 studies]; fasting glucose (BG) [SMD: -0.38 mmol/L (95% CI: -0.60 to -0.16 mmol/L; p < 0.001; 20 studies]; systolic blood pressure (SBP) [MD: -5.95 mmHg (95% CI: -7.98 to -3.92 mmHg; p < 0.001; 23 studies]; and diastolic blood pressure (DBP) [MD: -4.14 mmHg (95% CI: -6.19 to -2.08 mmHg; p < 0.001; 23 studies]. Furthermore, sub-group analyses identified that moderate intensity and combined exercise training significantly improved MetS risk factors (p < 0.05) except for HDL, with combined exercise being the most effective. Long duration (≥12 weeks) training also significantly improved MetS risk factors except for TG. Meta-regression revealed no moderating effects on any MetS risk variables. CONCLUSION: This study reinforces the importance of regular physical activity as a non-pharmacological tool in the reduction of MetS risk in post-menopausal women, with significant metabolic improvements seen in interventions spanning 8-10 weeks. Moderate intensity and combined training significantly benefitted abdominal obesity, dyslipidaemia, dysglycaemia and hypertension in post-menopausal women. Improvements in at least one MetS risk were also seen with other exercise modalities and intensities.

Passing on the exercise baton: What can endocrine patients learn from elite athletes?

As elite athletes demonstrate through the Olympic motto 'Citius, Altius, Fortius- Communiter', new performance records are driven forward by favourable skeletal muscle bioenergetics, cardiorespiratory, and endocrine system adaptations. At a recreational level, regular physical activity is an effective nonpharmacological therapy in the treatment of many endocrine conditions. However, the impact of physical exercise on endocrine function and how best to incorporate exercise therapy into clinical care are not well understood. Beyond the pursuit of an Olympic medal, elite athletes may therefore serve as role models for showcasing how exercise can help in the management of endocrine disorders and improve metabolic dysfunction. This review summarizes research evidence for clinicians who wish to understand endocrine changes in athletes who already perform high levels of activity as well as to encourage patients to exercise more safely. Herein, we detail the upper limits of athleticism to showcase the adaptability of human endocrine-metabolic-physiological systems. Then, we describe the growing research base that advocates the importance of understanding maladaptation to physical training and nutrition in males and females; especially the young. Finally, we explore the impact of physical activity in improving some endocrine disorders with guidance on how lessons can be taken from athletes training and incorporated into strategies to move more people more often.