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Background: Palmitoylethanolamide (PEA) has analgesic/anti-inflammatory properties that may be a suitable alternative to over-the-counter (OTC) non-steroidal analgesics/anti-inflammatories. While OTC pain medications can impair strength training adaptations, the mechanism of action of PEA is distinct from these and it may not negatively affect skeletal muscle adaptations to strength training. Methods: The primary aim of this study was to investigate the effects of daily PEA supplementation (350 mg Levagen + equivalent to 300 mg PEA) combined with 8-weeks of resistance training on lean body mass with secondary aims addressing strength, power, sleep, and wellbeing compared to placebo (PLA) in young, healthy, active adults. In a randomized, controlled, double-blinded trial, 52 untrained, recreationally active participants aged 18–35 y were allocated to either the PEA or PLA groups. Participants consumed either 2 × 175 mg Levagen + PEA or identically matched maltodextrin capsules during an 8-week period of whole-body resistance training. This trial assessed the pre- to post- changes in total and regional lean body mass, muscular strength (1-RM bench, isometric mid-thigh pull), muscular power [countermovement jump (CMJ), bench throw], pain associated with exercise training, sleep, and wellbeing compared with the PEA or PLA condition. Results: 48 Participants were included in the final intention to treat (ITT) analysis and we also conducted per protocol (PP) analysis (n = 42). There were no significant between-group differences for total or regional lean muscle mass post-intervention. There was a significantly higher jump height (CMJ) at week 10 in the PEA group compared to the PLA (Adjusted mean difference [95% CI] p-value; ITT: − 2.94 cm [− 5.15, − 0.74] p = 0.010; PP: − 2.93 cm [− 5.31, − 0.55] p = 0.017). The PLA group had higher 1-RM bench press post-intervention compared with the PEA group (ITT: 2.24 kg [0.12, 4.37] p = 0.039; PP: 2.73 kg [0.40, 5.06] p = 0.023). No significant treatment effects were noted for any of the other outcomes. Conclusion: PEA supplementation, when combined with 8 weeks of strength training, did not impair lean mass gains and it resulted in significantly higher dynamic lower-body power when compared with the PLA condition. Trial Registration: Australian New Zealand Clinical Trials Registry (ANZCTR: ACTRN12621001726842p). Key Findings: Palmitoylethanolamide (PEA) is a compound that works as an anti-inflammatory and analgesic for the management of pain that works on different biochemical pathways compared to other over-the-counter analgesics and non-steroidal anti-inflammatories. Our findings indicate that a daily dose of 300 mg of PEA administered during 8-weeks of strength training did not interfere with skeletal muscle hypertrophy gains and may improve lower body power (e.g., jump height) compared to the placebo group. PEA may fill the gap for athletes and the active population as an alternative method of pain management. [ABSTRACT FROM AUTHOR]

Background: There is a universal need to increase the number of adults meeting physical activity (PA) recommendations to help improve health. In recent years, electrically assisted bicycles (e‐bikes) have emerged as a promising method for supporting people to initiate and maintain physical activity levels. To the best of our knowledge, there have been no meta‐analyses conducted to quantify the difference in physiological responses between e‐cycling with electrical assistance, e‐cycling without assistance, conventional cycling, and walking. Methods: A systematic review and meta‐analysis was conducted following PRISMA guidelines. We identified short‐term e‐bike studies, which utilized a crossover design comparing physiological outcomes when e‐cycling with electrical assistance, e‐cycling without electrical assistance, conventional cycling, or walking. Energy expenditure (EE), heart rate (HR), oxygen consumption (VO2), power output (PO), and metabolic equivalents (METs) outcomes were included within the meta‐analysis. Results: Fourteen studies met our inclusion criteria (N = 239). E‐cycling with electrical assistance resulted in a lower energy expenditure (EE) [SMD = −0.46 (−0.98, 0.06), p = 0.08], heart rate (HR) [MD = −11.41 (−17.15, −5.68), p < 0.000, beats per minute], oxygen uptake (VO2) [SMD = −0.57 (−0.96, −0.17), p = 0.005], power output (PO) [MD = −31.19 (−47.19 to −15.18), p = 0.000, Watts], and metabolic equivalent (MET) response [MD = −0.83 (−1.52, −0.14), p = 0.02, METs], compared with conventional cycling. E‐cycling with moderate electrical assistance resulted in a greater HR response [MD 10.38 (−1.48, 22.23) p = 0.09, beats per minute], and VO2 response [SMD 0.34 (−0.14, 0.82) p = 0.16] compared with walking. Conclusions: E‐cycling was associated with increased physiological responses that can confer health benefits. [ABSTRACT FROM AUTHOR]

Supplemental digital content is available in the text. Purpose: Whole-body vibration (WBV) therapy has been reported to potentially act as an exercise mimetic by improving muscle function and exercise capacity in a variety of healthy and clinical populations. Considering the important role that microvascular blood flow plays in muscle metabolism and exercise capacity, we investigated the muscle microvascular responses of acute WBV to knee extension exercise (KEX) in healthy individuals. Methods: Eleven healthy adults (age: 33 ± 2 yr; body mass index: 23.6 ± 1.1 kg·m−2) underwent 3 min of WBV, or 3 min of KEX at 25% of one-repetition maximum, in a randomized order separated by a minimum of 72 h. Femoral arterial blood flow was measured via Doppler ultrasound, and thigh muscle microvascular blood flow was measured via contrast-enhanced ultrasound at baseline and throughout the 3-min postintervention recovery period. Results: Both WBV and KEX significantly increased peak microvascular blood flow (WBV, 5.6-fold; KEX, 21-fold; both P < 0.05) during the 3-min recovery period. Despite a similar increase in femoral arterial blood flow (~4-fold; both P < 0.05 vs baseline) and whole-body oxygen consumption measured by indirect calorimetry (WBV, 48%; KEX, 60%; both P < 0.05 vs baseline) in both conditions, microvascular blood flow was stimulated to a greater extent after KEX. Conclusion: A single 3-min session of WBV in healthy individuals is sufficient to significantly enhance muscle microvascular blood flow. Despite KEX providing a more potent stimulus, WBV may be an effective method for improving microvascular blood flow in populations reported to exhibit microvascular dysfunction such as patients with type 2 diabetes. [ABSTRACT FROM AUTHOR]

This study was designed to examine the biomechanical and physiological responses between cycling on the Axiom stationary ergometer (Axiom, Elite, Fontaniva, Italy) vs. field conditions for both uphill and level ground cycling. Nine cyclists performed cycling bouts in the laboratory on an Axiom stationary ergometer and on their personal road bikes in actual road cycling conditions in the field with three pedaling cadences during uphill and level cycling. Gross efficiency and cycling economy were lower (-10%) for the Axiom stationary ergometer compared with the field. The preferred pedaling cadence was higher for the Axiom stationary ergometer conditions compared with the field conditions only for uphill cycling. Our data suggests that simulated cycling using the Axiom stationary ergometer differs from actual cycling in the field. These results should be taken into account notably for improving the precision of the model of cycling performance, and when it is necessary to compare two cycling test conditions (field/laboratory, using different ergometers). [ABSTRACT FROM AUTHOR]

Insulin resistance is a major health risk, and although exercise clearly improves skeletal muscle insulin sensitivity, the mechanisms are unclear. Here we show that initiation of a euglycemic-hyperinsulinemic clamp 4 h after single-legged exercise in humans increased microvascular perfusion (determined by contrast-enhanced ultrasound) by 65% in the exercised leg and 25% in the rested leg (P < 0.05) and that leg glucose uptake increased 50% more (P < 0.05) in the exercised leg than in the rested leg. Importantly, infusion of the nitric oxide synthase inhibitor l-NG-monomethyl-l-arginine acetate (l-NMMA) into both femoral arteries reversed the insulin-stimulated increase in microvascular perfusion in both legs and abrogated the greater glucose uptake in the exercised compared with the rested leg. Skeletal muscle phosphorylation of TBC1D4 Ser318 and Ser704 and glycogen synthase activity were greater in the exercised leg before insulin and increased similarly in both legs during the clamp, and l-NMMA had no effect on these insulin-stimulated signaling pathways. Therefore, acute exercise increases insulin sensitivity of muscle by a coordinated increase in insulin-stimulated microvascular perfusion and molecular signaling at the level of TBC1D4 and glycogen synthase in muscle. This secures improved glucose delivery on the one hand and increased ability to take up and dispose of the delivered glucose on the other hand. [ABSTRACT FROM AUTHOR]

Aging is associated with a progressive decline in the capacity for physical activity. Central to this decline is a reduction in the maximal rate of oxygen utilization, or VO2 max. This critical perspective examines the roles played by the factors that determine the rate of muscle oxygen delivery versus those that determine the utilization of oxygen by muscle as a means of probing the reasons for VO2 max decline with aging. Reductions in muscle oxygen delivery, principally due to reduced cardiac output and perhaps also a maldistribution of cardiac output, appear to play the dominant role up until late middle age. On the other hand, there is a decline in skeletal muscle oxidative capacity with aging, due in part to mitochondrial dysfunction, which appears to play a particularly important role in extreme old age (senescence) where skeletal muscle VO2 max is observed to decline by approximately 50% even under conditions of similar oxygen delivery as young adult muscle. It is noteworthy that at least the structural aspects of the capillary bed do not appear to be reduced in a manner that would compromise the capacity for muscle oxygen diffusion even in senescence. [ABSTRACT FROM AUTHOR]