This study investigated the acute glucose response to low-intensity, moderate-intensity, and high-intensity interval exercise compared to no-exercise in healthy insufficiently active males using a four-arm, randomized, crossover design. Ten males (age: 37.3 ± 7.3 years, BMI: 29.3 ± 6.5 kg·m ) completed four 30-minute interventions at weekly intervals comprising low-intensity exercise (LIE) at ~35% V˙O R, moderate-intensity exercise (MIE) at ~50% V˙O R, high-intensity interval exercise (HIIE) at ~80% V˙O R, and a no-exercise control. Participants performed cycle ergometer exercise 30 minutes after finishing breakfast. Glucose response was assessed using a continuous glucose monitor under free-living conditions with dietary intake replicated. A significant effect for intensity on energy expenditure was identified (P < .001) with similar energy cost in MIE (mean ± SD: 869 ± 148 kJ) and HIIE (806 ± 145 kJ), which were both greater than LIE (633 ± 129 kJ). The pattern of glucose response between the interventions over time was different (P = .02). Glucose was lower 25 minutes into each of the HIIE, MIE and LIE trials respectively (mean difference ± SD: -0.7 ± 1.1; -0.9 ± 1.1; -0.6 ± 0.9 mmol·L ; P < .05) than in the no-exercise trial. Glucose response was not different between exercise intensities (P > .05). Twenty-four-hour AUC was not affected by exercise intensity (P = .75). There was a significant effect for exercise enjoyment (P = .02), with LIE (69 ± 4) preferred less than HIIE (mean ± SD: 84 ± 14; P = .02), MIE (73 ± 5; P = .03), and no-exercise (75 ± 4; P = .03). Exercise at any intensity 30 minutes after a meal affects glycemic regulation equally in insufficiently active males. Moderate to vigorous exercise intensities were preferred, and therefore, the exercise guidelines appear appropriate for the prevention of cardiometabolic disease.

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The aim of this study was to determine the relative and absolute reliability of second lactate turnpoint using fixed and individual blood lactate method in competitive cyclists. Twenty-eight male, well-trained cyclists (30.2 ± 10.1 years, 72.0 ± 7.4 kg, 177.3 ± 4.7 cm) were recruited to participate in this study. Cyclists completed two incremental cycling tests to exhaustion over a period of 7 days to determine their peak power output, maximal oxygen uptake, maximal heart rate, maximal blood lactate concentration and two lactate turnpoint criteria. The fixed blood concentration criterion (3.5 mM) and an individual criterion were assessed by a lactate-power curve, considering power output, heart rate and oxygen uptake. The main finding of this study was that both lactate turnpoint criteria showed identical low within-subject variation for power output (2.8% coefficient of variation). High values for test-retest correlations ranging from r = 0.70 to r = 0.94 were found for all variables in both threshold criteria. In conclusion, the individual and fixed method to determine the second lactate turnpoint showed similar high absolute and relative reliability in competitive cyclists.

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ObjectiveTo compare the effectiveness of accumulating exercise in multiple bouts of at least 10 min throughout a day with exercise completed in a single bout (continuous or interval), or no exercise, on glycaemic control and regulation in inactive people without diagnosed glycaemic dysfunction.DesignSystematic review and meta-analysis.Data sourcesSeven electronic databases were searched: CINAHL (EBSCO), Cochrane Library, EMBASE (Ovid), MEDLINE 1948-(Ovid), SCOPUS (Elsevier), SPORTDiscus (EBSCO) and Web of Science (ISI) with no restrictions on date and included all titles indexed up to February 2018.Eligibility criteria for selecting studiesArticles reporting insufficiently active adults (19 to 64 years) without metabolic dysfunction, measuring glycaemic control or regulation following at least 6 weeks of aerobic exercise.ResultsOnly one study compared accumulated exercise to single-bout exercise with no significant effect on fasting glucose (95% CI: −0.04 to 0.24 mmol·L-1) or fasting insulin (95% CI: −1.79 to 9.85 pmol·L-1) reported 48 hours after the final bout. No studies compared accumulated exercise with no-exercise. Compared with no-exercise, single-bout exercise reduces insulin resistance (mean difference (MD): −0.53 pmol·L-1; 95% CI: −0.93 to −0.13). Insulin resistance was clearly reduced with moderate-intensity (−0.68 (−1.28 to −0.09)) but not with high-intensity (−0.38 (−1.20 to 0.44)) exercise. Single-bout exercise was not statistically more beneficial than no-exercise for glycated haemoglobin (HbA1c) (MD: −0.11 %; 95% CI: −0.24 to 0.02) in metabolically healthy individuals.Summary/conclusionThe glycaemic response to accumulated exercise or single-bout exercise might not be different, however exercise intensity might influence the mechanisms generating the response.PROSPERO registration numberCRD42015025042.