European Journal of Applied Physiology最新文献

Background: While the health benefits of regular physical activity are well-documented, there is limited evidence specifically addressing its impact on male sexual function.

Methods: A systematic review was conducted to investigate the influence of physical activity practice on sexual function in men. The studies were sourced from PubMed, Embase, Virtual Health Library, Scopus, Web of Science and Cochrane through May 2024.The recommendations and criteria described in the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and Cochrane Handbook were followed. Two independent reviewers assessed the quality of the literature.

Results: A total of 15 studies were eligible. According to the studies, physical exercise is highly associated with better sexual function in patients without comorbidities, patients with diabetes mellitus, patients with chronic heart failure, and patients of different races. Exercise influences the production of nitric oxide, improves insulin sensitivity, reduces levels of pro-inflammatory cytokines, and increases testosterone levels. These effects can help maintain arterial stiffness, improve vascular function, support the maintenance of male erection, and improve sexual dysfunctions.

Clinical implications: Healthcare professionals might consider prescribing exercise for men with sexual dysfunction.

Conclusion: This systematic review provides evidence that physical activity practice improves sexual function.

We tested the hypothesis that due to well recognized thermoregulatory impairments, resulting in greater thermal strain, adults with well healed burn injuries will have heightened cardiovascular responses to exercise in the heat. Adults with burn injuries covering 20-40% body surface area (n = 10), > 40% body surface area (n = 11), and non-burned controls (n = 10) performed 1 h of treadmill walking at a fixed rate of metabolic heat production (~ 4.5 w/kg) in the heat (39 °C, 40% relative humidity). Core temperature, heart rate, stroke volume, and blood pressure were obtained at rest and during exercise. The increase in core temperature was 0.89 ± 0.40 °C for control, 0.92 ± 0.43 °C for 20-40%, and 1.30 ± 0.58 °C for > 40% (interaction: p = .08). Ending heart rate was greater in > 40% compared to control (142 ± 27 vs 118 ± 9 bpm; p = .03), however there was no difference between 20-40% and control (128 ± 24 vs 118 ± 9 bpm; p = .44). Ending rate pressure product was higher in the > 40% compared to control (21,326 ± 4327 vs 15,971 ± 2156 mmHg*bpm; p = .007), however there was no difference between 20-40% and control (18,698 ± 3741 vs 15,971 ± 2156 mmHg*bpm; p = .16). At 45-min into exercise, cardiac minute work was higher in the > 40% compared to control (577 ± 102 vs 467 ± 63 L/min*mmHg/m²; p = .02), but there was no difference between 20-40% and control (513 ± 82 vs 467 ± 63 L/min*mmHg/m²; p = .36). These findings show that well-healed burn survivors with large burn injuries, such as those covering > 40% of total body surface area, have increased cardiovascular strain during exercise heat stress.

Introduction: Buccal absorption of caffeine bypasses digestion, can elicit peak serum caffeine concentration within ~ 30 min of administration, and thereby may elicit cognitive benefits faster than ingesting caffeine. Caffeine mouth sprays are commercial products that involve sublingual delivery, but their ability to increase blood caffeine is unexamined.

Purpose: This study tested whether blood caffeine would be increased and reach peak concentrations sooner after using mouth spray compared to ingesting coffee or an energy drink.

Methods: Fourteen adults (6 males, 8 females; 24 ± 3 years, 69.9 ± 9.3 kg) abstained from caffeine for 16 h, ate a standardized breakfast, then consumed 60 mg of caffeine via either mouth spray, coffee, or energy drink in a randomized, crossover manner. In the following 90 min, serum caffeine was determined throughout, and cognitive function was assessed at ~ 30 and ~ 90 min.

Results: Serum caffeine was increased compared to baseline in all conditions (p < 0.0001) but was not different at any timepoint between the mouth spray, coffee, and energy drink (p = 0.06). Caffeine area under the curve was not different after mouth spray, coffee, or energy drink (61 [54-73], 82 [51-119], 68 [43-78] min*mg/L respectively, p = 0.22) nor was peak concentration (1.6 [1.2-1.8], 1.9 [1.4-2.4], 1.2 [0.8-3.0] mg/L respectively, p = 0.19). Within the mouth-spray condition, serum caffeine was higher than baseline from 10 to 90 min (p < 0.03) but not at 5 min (p = 0.50), and peak concentration occurred 90-min after use. Performance on cognitive tests was unaffected by caffeine type (p > 0.22).

Conclusion: Sublingual administration of caffeine via mouth spray did not increase serum caffeine concentration faster than ingesting caffeinated beverages.

Purpose: This study aimed to examine the effects of a single dose of a betalain-rich concentrate (BRC) on determinants of running performance and recovery lactate clearance.

Methods: In this a randomized, triple-blind, placebo-controlled, crossover trial, 17 male recreational runners (Age: 19.0 ± 1.0 years; Height: 176.8 ± 6.2 cm; Weight: 70.62 ± 8.1 kg; Body fat: 12.8 ± 0.03%; VO_2max: 58.9 ± 8.6 ml/kg/min) consumed an acute dose of a BRC (100 mg) or a placebo (100 mg of dextrose; CON) and performed a running economy protocol (RE) at velocities corresponding to 60% and 80% of maximal oxygen consumption (VO_2max) followed by a VO_2max test. Both exercise and recovery skeletal muscle oxygenation (SmO₂) were assessed via near-infrared spectroscopy (NIRS), and recovery lactate was obtained.

Results: BRC resulted in lower heart rate (HR) at velocities corresponding to 80% of VO_2max (p = 0.05) and maximum HR (HR_max; p = 0.01), and a lower rating of perceived exertion (RPE) at velocities corresponding to 60% of VO_2max (p = 0.02) when compared to CON. BRC also improved post-exercise SmO₂ at 3 (p = 0.05), 4 (p = 0.02), and 5 min (p = 0.01) but not lactate clearance (p > 0.05). BRC did not significantly improve RE or VO_2max (p > 0.05).

Conclusions: A single dose of BRC did not enhance RE or VO_2max. However, the observed improvements in exercise HR, RPE, and SmO₂ suggest that BRC may confer cardiovascular benefits for exercise and recovery.

Normobaric hypoxic resistance training (NHRT) has emerged as a novel approach to enhancing muscle strength, potentially offering advantages over conventional resistance training. However, its efficacy in healthy adults remains uncertain. This systematic review and meta-analysis aimed to evaluate the effects of NHRT on muscle strength indicators, including one-repetition maximum (1RM), isometric strength, and isokinetic strength, in healthy adults.

Methods: Following PRISMA 2020 guidelines, four databases (PubMed, Web of Science, SportDiscus, and CNKI) were searched from inception to October 25, 2024, for randomized controlled trials. Study quality was assessed using the Cochrane Risk of Bias tool. Effect sizes were calculated using Review Manager 5.4.

Results: A total of 22 RCTs involving 487 healthy adults were included. The meta-analysis revealed a significant small-to-moderate improvement in 1RM (SMD = 0.22, 95% CI [0.06, 0.38]) but no statistically significant effects on isometric strength (SMD = 0.32, 95% CI [-0.05, 0.70]) and isokinetic strength (SMD = 0.25, 95% CI [-0.11, 0.62]). Subgroup analyses indicated that oxygen concentrations of 14-16% and training loads of 60-80% 1RM produced the most substantial gains, particularly among untrained participants.

Conclusions: NHRT is a promising strategy for enhancing 1RM in healthy adults, with its effectiveness influenced by hypoxic levels, training load, and baseline training status. Optimal outcomes were observed at oxygen concentrations of 14-16% and moderate training loads (60-80% 1RM), particularly in untrained individuals. Further high-quality studies are warranted to confirm these outcomes and explore the underlying mechanisms.Registration number on PROSPEROCRD42024547100.

Purpose: This study assessed the test-retest reliability of TMS motor evoked potentials (MEPs) and silent periods at early, middle, and late phases of the rising time-torque curve during explosive voluntary contractions. We also investigated how the number of consecutively averaged measurements influenced reliability.

Methods: On two separate occasions 3-7 days apart, 14 adults performed several isometric explosive (1-s) contractions of the knee extensors, some of which were superimposed with TMS to elicit MEPs in the superficial quadriceps. Of those with TMS, stimulation was timed to elicit MEPs at either 45 (early), 115 (middle), or 190 ms (late) following contraction onset (16 with-TMS contractions per time condition). TMS was also superimposed at the plateau of 15 separate MVCs. Test-retest intraclass correlation coefficient (ICC) and coefficient of variation (CV) were calculated for MEPs and silent periods consecutively averaged over 3 to 15 separate contractions.

Results: No one condition/phase was more reliable than another. For MEP amplitude, in all conditions except the explosive late phase, ICCs generally increased, and CV decreased, with an increase in the number of averaged contractions, and were > 0.50 ICC and < 15% CV within seven contractions. For silent period, ICCs and CVs were unaffected by the number of consecutively averaged contractions and remained > 0.50 ICC and < 10% CV.

Conclusion: Test-retest reliability of TMS responses is comparable between phases of explosive contraction and at the plateau of MVC. To maximise reliability of MEPs during explosive contractions or MVCs, we recommend future studies average data across more than the 3-5 contractions typically reported in the literature investigating MEPs at MVC plateau.

Purpose: Single passive limb movement (sPLM) of the lower extremity is a simple and clinically relevant measure of the microvascular vasodilatory response to movement. A promising stimulus to improve microvascular health is ischemic conditioning (IC). We examined whether a single session of IC could improve microvascular reactivity to sPLM in young adults.

Methods: This was a blinded, crossover, randomized clinical trial. Participants were seated in an isokinetic dynamometer that passively moved the knee 90° at a frequency of 1 Hz while superficial femoral artery leg blood flow (LBF) was measured. The absolute and the relative peak changes in LBF were calculated as the difference from baseline. The time to peak was calculated from the start of sPLM to peak LBF. The total area under the curve (AUC) was the sum of LBF above baseline during the hyperemic response. For IC, the cuff was placed around the dominant thigh and repetitively inflated (225 mmHg) for 5 min, then deflated for 5 min (total 45 min). For sham IC, the cuff was inflated to 25 mmHg. The sPLM response was re-assessed ten minutes after IC.

Results: Twelve individuals completed the study (age 27 ± 3 years, 50% female). When controlling for resting LBF, heart rate, and sex, there was an interaction effect for absolute and relative peak change in LBF (p ≤ 0.048) but not time to peak or total AUC (p ≥ 0.17).

Conclusion: We show an acute bout of IC may improve the peak vasodilatory response to sPLM, potentially due to "preconditioning" the microvasculature.

Runners with Achilles tendinopathy have reduced neural drive to the gastrocnemius lateralis. Positioning feet-inwards (feet-in) can influence gastrocnemii activity in healthy individuals. Therefore, this study investigated if pointing (feet-in) during isometric plantarflexion would increase gastrocnemius lateralis electromyography root mean square amplitude (RMS) and motor unit discharge rates (MUDR), compared to feet-neutral (feet-neutral), in Achilles tendinopathy. High-density electromyograms were recorded from gastrocnemius lateralis and medialis, during 20-s feet-in and feet-neutral contraction, in runners with (n = 18) and without (n = 19) Achilles tendinopathy. During feet-in, gastrocnemius lateralis RMS was higher in both groups and gastrocnemius medialis RMS was lower in the Achilles tendinopathy, compared to feet-neutral. MUDR were lower during feet-in in gastrocnemius lateralis (p < 0.001) and in gastrocnemius medialis in the Achilles tendinopathy group. The Achilles tendinopathy group had lower triceps surae endurance during single leg heel raise. In summary, feet-in increases gastrocnemius lateralis RMS in both groups, conversely reducing MUDR in the Achilles tendinopathy group, compared to feet-neutral. Additionally, feet-in reduces gastrocnemius medialis RMS and MUDR only in the Achilles tendinopathy group, compared to feet-neutral. This would shift the gastrocnemius lateralis/medialis ratio excitation, favouring gastrocnemius lateralis. Nonetheless, while this strategy holds promise, it remains uncertain whether performing plantarflexion exercise with feet pointed inwards would provide additional benefits for the treatment of runners with Achilles tendinopathy. Our findings suggest that the increased gastrocnemius lateralis RMS during feet-in may not be as consequence of increased MUDR and, but it might be a result of recruitment of more motor units.

Background: There is a strong correlation between the level of physical activity undertaken during pregnancy and the health of both the mothers and the fetus. The physical activity guidelines for pregnancy recommend moderate to high-intensity exercise, yet in practice, few pregnant women currently engage in high-intensity exercise, and there is no consensus on its effect on pregnancy outcomes. The objective of this meta-analysis was to investigate the effects of high-intensity exercise on pregnancy outcomes and pregnancy complications in healthy pregnant women.

Methods: Electronic searches of the Cochrane Library, PubMed and Web of Science were conducted from the inception of the databases to 21 December 2023. The search used a range of relevant terms "pregnancy" "gestation" " physical activity" "exercise" to capture all potentially eligible results relating to exercise interventions during pregnancy. A total of 16 RCTs were analyzed. The indicators analyzed are GWG, EGWG, BW, LBW, VO₂/AT, Apgar score 1 and 5 min after birth, GDM, PIH.

Results: High-intensity exercise during pregnancy can effectively reduce the incidence of GDM compared to the control group (OR = 0.45, 95% CI = 0.30, 0.68, P = 0.0001). It also improves the 5-min Apgar score of newborns (MD = 0.09, 95% CI = 0.06, 0.12, P < 0.00001), and although the 1-min Apgar score was also improved, it was not significant (MD = 0.13, 95% CI = 0, 0.27, P = 0.05). In addition, pregnant women who performed high-intensity exercise during pregnancy had a much smaller rate of change of VO₂/AT than the control group (MD = 3.37, 95% CI = 1.25, 5.49, P = 0.002). However, there were no significant differences in the preterm birth rate (OR = 0.95, 95% CI = 0.58, 1.55, P = 0.83), gestational week of delivery (MD = 0.04, 95% CI = - 0.12, 0.20, P = 0.62), prevalence of GWG (MD = - 0.91, 95% CI = - 1.96, 0.14, P = 0.09), EGWG (OR = 0.98, 95% CI = 0.47, 2.03, P = 0.95), BW (MD = - 33.19, 95% CI = - 84.72, 18.34, P = 0.21), LBW (OR = 2.44, 95% CI = 0.81, 7.29, P = 0.11) and prevalence of PIH (OR = 0.6, 95% CI = 0.31, 1.17, P = 0.14) between high-intensity exercise group and control group.

Conclusions: The study suggests that performing high-intensity exercise during pregnancy does not have adverse effects on pregnancy outcomes for healthy pregnant women. In addition, it reduces pregnancy complications and reduces the risk of developing gestational diabetes. The rate at which maximum sustained exercise capacity decreases is delayed or remains unchanged. These findings can assist pregnant women in selecting a suitable exercise intensity during pregnancy and provide a scientific basis for physicians to prescribe high-intensity exercise.

Trial registration: PROSPERO trial registration CRD42024503843.