The use of a to-fatigue hypertrophy based resistance exercise protocol provides the necessary stimulus to increase peripheral serum BDNF. Mechanistically, the presence of lactate does not appear to drive the BDNF response during resistance exercise.

Despite the acknowledgment of exercise as a cornerstone in the management of type 2 diabetes (T2D), the importance of exercise timing has only recently been considered. Purpose This study sought to determine the effect of diurnal exercise timing on glycemic control in individuals enrolled in a 12-wk supervised multimodal exercise training program. A secondary aim was to determine the effect of diurnal exercise timing on the circadian rhythm of wrist skin temperature. Methods Forty sedentary, overweight adults (mean ± SD, age = 51 ± 13 yr; body mass index = 30.9 ± 4.2 kg·m−2; women, n = 23) with and without (n = 20) T2D diagnosis were randomly allocated to either a morning (amEX) or an evening (pmEX) exercise training group. The supervised 12-wk (3 d·wk−1) program, comprised 30 min of moderate-intensity walking and 4 resistance-based exercises (3 sets, 12–18 repetitions each). Glycemic outcomes (glycated hemoglobin, fasting glucose, postprandial glucose) and wrist skin temperature were assessed at baseline and postintervention. Results Exercise training improved (main effect of time, all P < 0.01) all glycemic outcomes; however, this was independent of allocation to either the amEX (Hedge’s g, 0.23–0.90) or the pmEX (Hedge’s g, 0.16–0.90) group. Accordingly, the adopted exercise training program did not alter the circadian rhythm of skin temperature. When only T2D individuals were compared, amEX demonstrated greater effects (all Hedge’s g) on glycated hemoglobin (amEX, 0.57; pmEX, 0.32), fasting glucose (amEX, 0.91; pmEX, 0.53), and postprandial glucose (amEX, 1.12; pmEX, 0.71) but was not statistically different. Conclusions Twelve weeks of multimodal exercise training improved glycemic control and postprandial glycemic responses in overweight non-T2D and T2D individuals. However, no distinct glycemic benefits or alterations in circadian rhythm were associated with morning versus evening exercise, when performed three times per week in this cohort.

Introduction: Blood flow restriction (BFR) during low-load resistance exercise increases muscle size similarly to high-load training, and may be an alternative to lifting heavy weights for older people at risk of sarcopenia. However, few studies have addressed the safety of such exercise in older people, or whether this is impacted by the actual exercises performed during training. This study aimed to compare the acute hemodynamic and perceptual responses during low-load BFR exercise to unrestricted low-load and high-load exercise in older women, and to determine whether these responses depend on the type of exercise performed.Methods: Fifteen older women (63–75 year) were assessed for maximal strength (1RM) in the leg press and leg extension. Participants then completed three protocols using these exercises in a randomized order: (1) low-load exercise (LL); (2) low-load exercise with BFR (LLBFR), and; (3) high-load exercise (HL). Blood pressure was assessed at baseline and after each set, and impedance cardiography measured cardiovascular function during trials. Rating of perceived exertion (RPE) and muscle soreness scores were obtained throughout trials.Results: Baseline hemodynamic values were consistent between trials. Systolic, diastolic, and mean arterial pressures were higher in LLBFR compared with HL and LL (p ≤ 0.021). The LL condition resulted in lower heart rate (p ≤ 0.002) and rate-pressure product (p ≤ 0.011) responses compared with LLBFR and HL. The leg press generally conferred greater hemodynamic and perceptual demands than the leg extension for all conditions (p ≤ 0.002). RPE was lower during LL compared with LLBFR and HL (p ≤ 0.008), and there were no between-condition differences in perceived muscle soreness.Conclusion: The blood pressure data indicate that LLBFR causes greater stress on the vasculature than LL and HL exercise, and that the leg press was generally more demanding than the leg extension. While additional cardiovascular measures were similar between LLBFR and HL conditions, caution should be advised when prescribing BFR exercise for individuals with compromised cardiac or vascular function. Nevertheless, LLBFR and HL exercise were perceived similarly, indicating that BFR training may be viable for healthy older people.

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Common estimates of external training intensity for resistance exercise do not incorporate inter-set recovery duration, and might not reflect the overall demands of training. This study aimed to assess novel metrics of exercise density (ED) during resistance exercise, and how these related to a physiological marker of internal training intensity as well as traditional measures of external training intensity and volume. Thirteen males and seven females performed two bouts of resistance exercise focused on developing strength (5 sets of 5 repetitions with 5-repetition maximum; 180 s recovery) and hypertrophy (3 sets of 10 repetitions with 10-repetition maximum; 60 s recovery). Blood lactate concentration was measured to quantify internal training intensity. Specific metrics of external volume (mechanical work, volume load and total repetitions) and intensity (average weight lifted and ED) were calculated. Despite lower average weights and no difference in mechanical work or volume load, blood lactate was greater following hypertrophy compared with the strength condition. This finding was consistent with higher measures of ED in the hypertrophy compared with the strength condition. Greater ED during hypertrophy resistance exercise, along with the significant association with changes in blood lactate, indicates that ED metrics are reflective of the sessional intensity for resistance exercise.