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Introduction: Post-activation performance enhancement (PAPE) cannot be clearly distinguished from and may be explained in large by warm-up effects. To disentangle PAPE from a systemic warm-up effect, we conducted three randomized crossover trials (RCT). Methods: Each RCT consisted of a familiarization/one-repetition-maximum (1RM) assessment session followed by two interventional sessions (random order). In Study I, 18 participants (age: 26 ± 4 years; height: 1.84 ± 0.06 m; mass: 83.7 ± 8.7 kg; Squat-1RM: 146 ± 19 kg) performed either a 3-s isometric squat at 130%1RM or a 6-s isometric squat at 65%1RM. In Study II, 28 participants (11 female; age: 23 ± 3 years; height: 1.77 ± 0.08 m; mass: 76.5 ± 10.4 kg; Squat-1RM: 109 ± 38 kg) completed either Squat (3 × 3 repetitions, 85%1RM) or local electromyostimulation of the quadriceps muscle (85% of individual pain threshold). In Study III, 20 participants (6 female, age: 25.0 ± 3.5 years, mass: 78.5 ± 15.8 kg, height: 1.75 ± 0.08 m; SQ-1RM: 114 ± 33 kg, chest-press-1RM: 74 ± 29 kg) performed either squats or chest press (4 repetitions, 80%1RM). Counter-Movement-Jump height (CMJ) was assessed after a general (PRE) and/or muscle-specific warm-up (POST_WU) and for up to 11 min after the PAPE protocols. To identify possible differences in CMJ between the experimental conditions, mixed-design ANOVA models were used for each study individually, with condition and time modelled as fixed effects, while participants were included as a random effect blocking factor. The level of statistical significance was set at α = 5%. Results: In studies I and II, significant effects for time (p < 0.05, ωp 2 = 0.06 and p < 0.001, ωp 2 = 0.43) were found with the highest CMJ compared to all other time points at PRE (≤8.2 ± 4.6%, standardized mean difference: ≤0.39), regardless of condition. In study III, no significant effects were observed. Discussion: Thus, PAPE protocols do not further improve jumping performance compared to a general and muscle-specific traditional warm-up. Prior to tasks requiring explosive strength, general and sport-specific warm-up strategies should be used.
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The decision of the Union Internationale de Pentathlon Moderne to replace horse riding with Obstacle after the 2024 Olympic Games challenges training, testing, and recovery management in Modern Pentathlon. This commentary discusses physiological, technical, and tactical effects of rule changes in the 5 disciplines with a specific focus on the new discipline Obstacle. Modern Pentathlon requires athletes to develop specific endurance capacities relying on both the aerobic and anaerobic systems while simultaneously increasing lower- and upper-body strength capabilities. In addition, movements must be repeatedly executed in an explosive and precise manner. Running and swimming must be fast but economical. Swapping from horse riding to Obstacle will prioritize the explosive strength of the upper extremities and core while keeping high levels of endurance and precision in swimming, fencing, and shooting. Moreover, condensing the Modern Pentathlon competition to a 90-minute television-friendly format enables more competitions in the future. Athletes and coaches will thus also need to develop and maintain effective individual peri-exercise routines (before, during, and after the competition) to successfully meet the resulting tactical and physical challenges of the new format. This commentary aims to stimulate the discussion on the effect of the Union Internationale de Pentathlon Moderne's decisions to replace riding with the new Obstacle discipline and implement a more television-friendly format with a focus on physiological, technical, and tactical aspects.
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The kynurenine pathway (KP) of tryptophan degradation generates several metabolites such as kynurenine (KYN) or kynurenic acid (KA) that serve as endogenous ligands of the aryl hydrocarbon receptor (AHR). Due to its distinct biological roles particularly modulating the immune system, the AHR is a current therapeutic target across different inflammation-related diseases. Here, we show an acute exercise-induced increase in AHR ligand availability on a systemic level and a kynurenine pathway activation in peripheral blood mononuclear cells (PBMCs). Concurrently, the AHR is activated in PBMCs following acute exercise. Exercise effects on both, kynurenic acid and AHR activation in PBMCs were greater in response to high-intensity interval exercise (HIIE) (50 min, six 3-min intervals at 90% VÌo2peak, and 3-min intervals at 50% VÌo2peak in between) compared with workload-matched moderate-intensity continuous exercise (MICE) (50 min). In conclusion, these data indicate a novel mechanistic link in how exercise modulates the immune system through the kynurenine pathway-AHR axis, potentially underlying exercise-induced benefits in various chronic diseases.NEW & NOTEWORTHY The findings of this study show that acute endurance exercise activates a receptor that has been described to integrate metabolic signals into the immune system. We uncover a potential mechanistic link on how exercise modulates the immune system through the kynurenine pathway-AHR axis, potentially underlying exercise-induced benefits in various chronic diseases and of relevance for other cell types.
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Ácido Quinurénico , Quinurenina , Leucocitos Mononucleares , Receptores de Hidrocarburo de Aril , Receptores de Hidrocarburo de Aril/metabolismo , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/inmunología , Quinurenina/metabolismo , Masculino , Animales , Ácido Quinurénico/metabolismo , Ácido Quinurénico/sangre , Ejercicio Físico/fisiología , Ratones , Ratones Endogámicos C57BL , Humanos , Condicionamiento Físico Animal/fisiología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Transducción de Señal , Triptófano/metabolismo , Triptófano/sangreRESUMEN
OBJECTIVE: Wheelchair basketball (WCB) demands high-intensity training due to its intermittent nature. However, acute oxygen uptake (VËO2) in handcycling is restricted. Combining handcycling with low-frequency electromyostimulation (LF-EMS) may enhance VËO2 in elite WBC athletes. DESIGN: Randomized crossover trail. SUBJECTS: Twelve German national team WCB players (age: 25.6 [5.6] years, height: 1.75 [0.16] m, mass: 74.0 [21.7] kg, classification: 2.92 [1.26]). METHOD: Participants underwent 2×5 min of handcycling (60 rpm, ¾ bodyweight resistance in watts) (HANDCYCLE) and 2×5 min of handcycling with concurrent LF-EMS (EMS_HANDCYCLE). LF-EMS (4Hz, 350µs, continuous stimulation) targeted gluteal, quadriceps, and calf muscles, adjusted to individual pain thresholds (buttocks: 69.5 [22.3] mA, thighs: 66.8 [20.0] mA, calves: 68.9 [31.5] mA). RESULTS: Significant mode-dependent differences between HANDCYCLE and EMS_HANDCYCLE were found in VËO2 (17.60 [3.57] vs 19.23 [4.37] ml min-1 kg-1, p = 0.001) and oxygen pulse (16.69 [4.51] vs 18.41 [5.17] ml, p = 0.002). ΔLactate was significantly lower in HANDCYCLE (0.04 [0.28] vs 0.31 [0.26] mmol l-1). Although perceived effort did not differ (p = 0.293), discomfort was rated lower in HANDCYCLE (1.44 [1.28] vs 3.94 [2.14], p = 0.002). CONCLUSION: LF-EMS applied to the lower extremities increases oxygen demand during submaximal handcycling. Thus, longitudinal application of LF-EMS should be investigated as a potential training stimulus to improve aerobic capacity in wheelchair athletes.
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Baloncesto , Estudios Cruzados , Consumo de Oxígeno , Silla de Ruedas , Humanos , Adulto , Baloncesto/fisiología , Consumo de Oxígeno/fisiología , Masculino , Adulto Joven , Músculo Esquelético/metabolismo , AtletasRESUMEN
ABSTRACT: Held, S, Rappelt, L, Rein, R, Deutsch, J-P, Wiedenmann, T, and Donath, L. Five-week, low-intensity, blood flow restriction rowing improves VÌ o2 max in elite rowers. J Strength Cond Res 38(6): e299-e303, 2024-This controlled intervention study examined the effects of low-intensity rowing with blood flow restriction (BFR) on maximal oxygen uptake (VÌ o2 max), peak power output during ramp testing (PPO), and 2000-m time trial performance (P2k). Eleven, highly elite, male rowers (22.1 ± 1.6 years; 92.6 ± 3.8 kg; 1.93 ± 0.04 m; 7.9. ± 2.2 years rowing experience; 20.4 ± 2.0 h·w -1 training volume; 11.9 ± 1.1 session per week) trained 5 weeks without BFR (Base) followed by a 5-week BFR intervention period. BFR of the lower limb was applied through customized elastic wraps. BFR took place 3 times a week (accumulated net pBFR: 60 min·wk -1 ; occlusion per session: 2 times 10 min·session -1 ) and was used exclusively at low intensities (<2 mmol·L -1 ). VÌ o2 max, PPO, and P2k were examined before, between, and after both intervention periods. Bayesian's credible intervals revealed relevantly increased VÌ o2 max +0.30 L·min -1 (95% credible interval: +0.00 to +0.61 L·min -1 ) adaptations through BFR. By contrast, PPO +14 W (-6 to +34 W) and P2k -5 W (-14 to +3 W) were not noticeably affected by the BFR intervention. This study revealed that 15 sessions of BFR application with a cumulative total BFR load of 5 h over a 5-week macrocycle increased VÌ o2 max remarkably. Thus, pBFR might serve as a promising tool to improve aerobic capacity in highly trained elite rowers.
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Rendimiento Atlético , Consumo de Oxígeno , Flujo Sanguíneo Regional , Deportes Acuáticos , Humanos , Masculino , Deportes Acuáticos/fisiología , Consumo de Oxígeno/fisiología , Adulto Joven , Rendimiento Atlético/fisiología , Flujo Sanguíneo Regional/fisiología , Extremidad Inferior/irrigación sanguínea , Extremidad Inferior/fisiología , Adulto , Acondicionamiento Físico Humano/fisiología , Acondicionamiento Físico Humano/métodosRESUMEN
The maximal lactate accumulation rate (VLamax) has been linked to lactic anaerobic performance. Hence, accurate and reliable assessment is crucial in sport-specific performance testing. Thus, between-day reliability data of rowing-specific VLamax assessment was examined. Seventeen trained rowers (eight females and nine males; 19.5±5.2 yrs; 1.76±0.08 m; 70.2±8.9 kg; VÌO2max: 54±13 ml/min/kg) performed 20-s sprint tests on two separate days (one week apart) on a rowing ergometer. VLamax, peak lactate concentration, time to peak lactate, and mean rowing power were measured. Good to excellent intraclass correlation coefficients (ICCs), low standard error of measurement (SEM), and acceptable levels of agreement (LoAs; 90% confidence interval) for VLamax (ICC=0.85; SEM=0.02 mmol/L/s; LoA±0.09 mmol/L/s), peak lactate (ICC=0.88; SEM=0.3 mmol/L; LoA±1.4 mmol/l), time to peak lactate (ICC=0.92; SEM=0.1 min; LoA±0.5 min), and mean rowing power (ICC=0.98; SEM=3 W; LoA±39 W) were observed. In addition, VLamax was highly correlated (r=0.96; p≤0.001) to rowing power. Thus, VLamax and sprint performance parameters can be measured highly reliably using this sport-specific sprint test in rowing.
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Deportes , Deportes Acuáticos , Humanos , Femenino , Masculino , Ácido Láctico , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Exercise training recommendations for seniors include the targeted training of strength, balance, endurance and flexibility domains. Agility training (AT) is conceptualized as a multi-component and time-efficient training framework for older adults to improve physical, functional and cognitive health domains that are relevant for maintaining activities of daily living. The aim of this one-year trial was to comparatively evaluate the effects of agility training on physical and cognitive function. METHODS: Seventy-nine healthy older adults (AT: 61.5% female, 70.8 ± 4.8 years, 27.7 ± 4.2 kg/m2; CG: 60.5% female, 69.6 ± 4.7 years, 27.5 ± 4.4 kg/m2) took part in this one-year randomized controlled intervention and were either assigned to the agility training group (AT) with two weekly 60 min AT sessions or to the control group (CG), receiving no treatment. Participants were assessed pre, intermediate and post intervention for strength and power, balance, gait speed under multi-task conditions, aerobic capacity as well as cognitive performance. Linear mixed effects models were used to analyze the effect of treatment over time. RESULTS: Fifty-four participants (AG: 25, CG: 29) were analyzed, most drop-outs attributed to COVID-19 (17/30 dropouts). Adherence was good (75%) of 90 offered sessions. Notable effects in favor of AT were found for gait parameters in single (d = 0.355, Δ = 4.3%), dual (d = 0.375, Δ = 6.1%) and triple (d = 0.376, Δ = 6.4%) task conditions, counter movement jump performance (strength and power) (d = 0.203, Δ = 6.9%), static one leg balance (d = 0.256, Δ = 12.33%) and n-back reaction time (cognitive performance) (d = 0.204, Δ = 3.8%). No effects were found for the remaining outcomes (d < 0.175). CONCLUSION: AT might serve as an integrative training approach for older adults particularly improving gait and lower limb power parameters. It seems suitable to improve a broad range of seniors' health domains and should replace isolated training of these domains. However, individual variation and progression of exercises should be considered when programming agility training providing adequate challenges throughout a long-term intervention for all participants. TRIAL REGISTRATION: DRKS, DRKS00017469 . Registered 19 June 2019-Retrospectively registered.
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PURPOSE: Acute exercise elicits a transient anti-inflammatory state during the early recovery period. Since recent studies reported on regimen-specific effects on immune-related humoral factors and cellular subsets, this study compared the effects of intensity- and time-matched acute interval and continuous exercise on peripheral anti-inflammatory cellular and humoral immune parameters with a particular focus on the PD-1 expression in CD4+ regulatory T cells (Tregs). METHODS: Twenty-four recreationally active runners (age: 29.7 ± 4.3 years, BMI: 22.2 ± 2.4, VO2peak: 56.6 ± 6.4 ml × kg-1 × min-1) participated in this crossover RCT. Each subject conducted a moderate continuous (MCE) and a high-intensity interval exercise (HIIE) session in a counterbalanced design. Blood was drawn before, immediately after, and 1 h after exercise. Treg subsets and levels of PD-1 and Foxp3 were assessed by flow cytometry. Serum levels of IL-10 and IL-6 were quantified by ELISA. RESULTS: PD-1 levels on Tregs increased within the recovery period after HIIE (p < .001) and MCE (p < 0.001). Total counts of Tregs (HIIE: p = 0.044; MCE: p = .021), naïve Tregs (HIIE: p < 0.001; MCE: p < 0.001), and PD-1+ effector Tregs (eTregs) (HIIE: p = .002) decreased 1 h after exercise. IL-10 increased 1 h after HIIE (p < 0.001) and MCE (p = 0.018), while IL-6 increased immediately after both HIIE (p = 0.031) and MCE (p = 0.021). Correlations between changes in IL-6 and IL-10 (p = 0.017, r = 0.379) and baseline VO2peak and Treg frequency (p = 0.002, r = 0.660) were identified. CONCLUSION: This is the first study that investigates PD-1 expression in circulating Tregs after acute exercise, revealing an increase in PD-1 levels on eTregs during the early recovery period after intensity- and time-matched HIIE and MCE. Future studies are needed to investigate the PD-1 signalosome in eTregs, together with the expression of key effector molecules (i.e., IL-10, TGF-ß, IL-35, CTLA-4) to elucidate PD-1-dependent changes in cellular function. Based on changes in serum cytokines, this study further reveals a regimen-independent establishment of an anti-inflammatory milieu and underpins the role of the IL-6/IL-10 axis.
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Entrenamiento de Intervalos de Alta Intensidad , Interleucina-10 , Adulto , Humanos , Antiinflamatorios , Ejercicio Físico , Interleucina-6 , Receptor de Muerte Celular Programada 1RESUMEN
The combination of strength training with complementary whole-body electromyostimulation (WB-EMS) and plyometric exercises has been shown to increase strength and jumping performance in athletes. In elite sport, however, the mesocycles of training are often organized according to block periodization. Furthermore, WB-EMS is often applied onto static strength exercises, which may hamper the transfer into more sport-specific tasks. Thus, this study aimed at investigating whether four weeks of strength training with complementary dynamic vs. static WB-EMS followed by a four-week block of plyometric training increases maximal strength and jumping performance. A total of n = 26 (13 female/13 male) trained adults (20.8 ± 2.2 years, 69.5 ± 9.5kg, 9.7 ± 6.1h of training/w) were randomly assigned to a static (STA) or volume-, load- and work-to-rest-ratio-matched dynamic training group (DYN). Before (PRE), after four weeks (three times weekly) of WB-EMS training (MID) and a subsequent four-week block (twice weekly) of plyometric training (POST), maximal voluntary contraction (MVC) at leg extension (LE), leg curl (LC) and leg press machines (LP) and jumping performance (SJ, Squat Jump; CMJ, counter-movement-jump; DJ, drop-jump) were assessed. Furthermore, perceived effort (RPE) was rated for each set and subsequently averaged for each session. MVC at LP notably increased between PRE and POST in both STA (2335 ± 539 vs. 2653 ± 659N, standardized mean difference [SMD] = 0.528) and DYN (2483 ± 714N vs. 2885 ± 843N, SMD = 0.515). Reactive strength index of DJ showed significant differences between STA and DYN at MID (162.2 ± 26.4 vs. 123.1 ± 26.5 cm·s-1, p = 0.002, SMD = 1.478) and POST (166.1 ± 28.0 vs. 136.2 ± 31.7 cm·s-1, p = 0.02, SMD = 0.997). Furthermore, there was a significant effect for RPE, with STA rating perceived effort higher than DYN (6.76 ± 0.32 vs. 6.33 ± 0.47 a.u., p = 0.013, SMD = 1.058). When employing a training block of high-density WB-EMS both static and dynamic exercises lead to similar adaptations.
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Terapia por Estimulación Eléctrica , Entrenamiento de Fuerza , Adulto , Humanos , Masculino , Femenino , Ejercicio Físico/fisiología , Terapia por Ejercicio , Levantamiento de PesoRESUMEN
Introduction: Low-intensity endurance training is frequently performed at gradually higher training intensities than intended, resulting in a shift towards threshold training. By restricting oral breathing and only allowing for nasal breathing this shift might be reduced. Methods: Nineteen physically healthy adults (3 females, age: 26.5 ± 5.1 years; height: 1.77 ± 0.08 m; body mass: 77.3 ± 11.4 kg; VO2peak: 53.4 ± 6.6 mL·kg-1 min-1) performed 60 min of self-selected, similar (144.7 ± 56.3 vs. 147.0 ± 54.2 W, p = 0.60) low-intensity cycling with breathing restriction (nasal-only breathing) and without restrictions (oro-nasal breathing). During these sessions heart rate, respiratory gas exchange data and power output data were recorded continuously. Results: Total ventilation (p < 0.001, ηp 2 = 0.45), carbon dioxide release (p = 0.02, ηp 2 = 0.28), oxygen uptake (p = 0.03, ηp 2 = 0.23), and breathing frequency (p = 0.01, ηp 2 = 0.35) were lower during nasal-only breathing. Furthermore, lower capillary blood lactate concentrations were found towards the end of the training session during nasal-only breathing (time x condition-interaction effect: p = 0.02, ηp 2 = 0.17). Even though discomfort was rated marginally higher during nasal-only breathing (p = 0.03, ηp 2 = 0.24), ratings of perceived effort did not differ between the two conditions (p ≥ 0.06, ηp 2 = 0.01). No significant "condition" differences were found for intensity distribution (time spent in training zone quantified by power output and heart rate) (p ≥ 0.24, ηp 2 ≤ 0.07). Conclusion: Nasal-only breathing seems to be associated with possible physiological changes that may help to maintain physical health in endurance athletes during low intensity endurance training. However, it did not prevent participants from performing low-intensity training at higher intensities than intended. Longitudinal studies are warranted to evaluate longitudinal responses of changes in breathing patterns.
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Grip and elbow flexor strength and endurance are crucial performance surrogates in competitive climbing. Thus, we examined the effects of blood flow restricted (BFR) climbing on grip and elbow flexor performance. Fifteen trained climbers (8 females; 20.8 ± 7.0 yrs; 1.72 ± 0.08â m; 63.0 ± 9.7â kg; 21.7 ± 2.7 IRCRCA grade) were either assigned to the intervention (BFR) or control (noBFR) group, using the minimization method (Strata: age, height, body mass, gender, and IRCRA grade). While BFR was used during low-intensity climbing training (2-times 10â min/session; 3-times/week), noBFR followed identical training protocols without BFR over 5 weeks. BFR of the upper limb was applied via customized pneumatic cuffs (occlusion pressure: 120 ± 23 mmHg, 75%; occlusion pressure). Endurance and strength performances were assessed via one-handed rung pulling (GripSTRENGTH), one-handed bent arm lock off at 90° (ArmSTRENGTH), static-intermitted finger hang (GripENDURANCE), and bent arm hang (ArmENDURANCE). Bayesian credible intervals revealed increased GripENDURANCE (+21 s (95% credible interval: -2 to 43â s)) and ArmENDURANCE +11 s (-5 to 27â s); adaptations via BFR. In contrast, GripSTRENGTH +4 N (-40 to 48â N) and ArmSTRENGTH +4 N (-68 to 75â N) were not affected by the BFR intervention. Fifteen cumulative sessions of BFR application with a cumulative total BFR load of 5â h over a 5 weeks macrocycle remarkably increased grip and elbow flexor endurance. Thus, BFR might serve as a promising means to improve relevant performance surrogates in trained climbers.
Blood flow restricted (BFR) climbing induced superior grip and elbow flexor endurance adaptations compared to non-restricted climbing training over a 5-week lasting training periodBFR and non-BFR climbing training induced similar grip and elbow flexor strength adaptationsTherefore, BFR served as a feasible, promising and beneficial complementary training stimuli additionally to the sheduled climbing training program.
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Codo , Entrenamiento de Fuerza , Femenino , Humanos , Teorema de Bayes , Músculo Esquelético/fisiología , Fuerza de la Mano/fisiología , Extremidad Superior , Flujo Sanguíneo Regional/fisiologíaRESUMEN
INTRODUCTION: This systematic review and network meta-analysis assessed via direct and indirect comparison the occurrence and magnitude of effects following different nutritional supplementation strategies and exercise interventions on acute and chronic rowing performance and its surrogates. METHODS: PubMed, Web of Science, PsycNET and SPORTDiscus searches were conducted until March 2022 to identify studies that met the following inclusion criteria: (a) controlled trials, (b) rowing performance and its surrogate parameters as outcomes, and (c) peer-reviewed and published in English. Frequentist network meta-analytical approaches were calculated based on standardized mean differences (SMD) using random effects models. RESULTS: 71 studies with 1229 healthy rowers (aged 21.5 ± 3.0 years) were included and two main networks (acute and chronic) with each two subnetworks for nutrition and exercise have been created. Both networks revealed low heterogeneity and non-significant inconsistency (I2 ≤ 35.0% and Q statistics: p ≥ 0.12). Based on P-score rankings, while caffeine (P-score 84%; SMD 0.43) revealed relevantly favorable effects in terms of acute rowing performance enhancement, whilst prior weight reduction (P-score 10%; SMD - 0.48) and extensive preload (P-score 18%; SMD - 0.34) impaired acute rowing performance. Chronic blood flow restriction training (P-score 96%; SMD 1.26) and the combination of ß-hydroxy-ß-methylbutyrate and creatine (P-score 91%; SMD 1.04) induced remarkably large positive effects, while chronic spirulina (P-score 7%; SMD - 1.05) and black currant (P-score 9%; SMD - 0.88) supplementation revealed impairment effects. CONCLUSION: Homogeneous and consistent findings from numerous studies indicate that the choice of nutritional supplementation strategy and exercise training regimen are vital for acute and chronic performance enhancement in rowing.
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Ejercicio Físico , Deportes Acuáticos , Humanos , Estado de Salud , Estado Nutricional , CafeínaRESUMEN
The time spent above 90% of maximal oxygen uptake ( V Ë O2max) during high-intensity interval training (HIIT) sessions is intended to be maximized to improve V Ë O2max. Since uphill running serves as a promising means to increase metabolic cost, we compared even and moderately inclined running in terms of time ≥90% V Ë O2max and its corresponding physiological surrogates. Seventeen well-trained runners (8 females & 9 males; 25.8 ± 6.8yrs; 1.75 ± 0.08m; 63.2 ± 8.4kg; V Ë O2max: 63.3 ± 4.2 ml/min/kg) randomly completed both a horizontal (1% incline) and uphill (8% incline) HIIT protocol (4-times 5min, with 90s rest). Mean oxygen uptake ( V Ë O2mean), peak oxygen uptake ( V Ë O2peak), lactate, heart rate (HR), and perceived exertion (RPE) were measured. Uphill HIIT revealed higher (p ≤ 0.012; partial eta-squared (pes) ≥ 0.351) V Ë O2mean (uphill: 3.3 ± 0.6 vs. horizontal: 3.2 ± 0.5 L/min; standardized mean difference (SMD) = 0.15), V Ë O2peak (uphill: 4.0 ± 0.7 vs. horizontal: 3.8 ± 0.7 L/min; SMD = 0.19), and accumulated time ≥90% V Ë O2max (uphill: 9.1 ± 4.6 vs. horizontal: 6.4 ± 4.0 min; SMD = 0.62) compared to even HIIT. Lactate, HR, and RPE responses did not show mode*time rANOVA interaction effects (p ≥ 0.097; pes ≤0.14). Compared to horizontal HIIT, moderate uphill HIIT revealed higher fractions of V Ë O2max at comparable perceived efforts, heartrate and lactate response. Therefore, moderate uphill HiiT notably increased time spent above 90% V Ë O2max.
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Chronic blood flow restriction (BFR) training has been shown to improve drop jumping (DJ) and balance performance. However, the acute effects of low intensity BFR cycling on DJ and balance indices have not yet been examined. 28 healthy young adults (9 female; 21.8 ± 2.7years; 1.79 ± 0.08m; 73.9 ± 9.5kg) performed DJ and balance testing before and immediately after 20min low intensity cycling (40% of power at maximal oxygen uptake) with (BFR) and without BFR (noBFR). For DJ related parameters, no significant mode × time interactions were found (p ≥ 0.221, ηp 2 ≤ 0.06). Large time effects for DJ heights and the reactive strength index were observed (p < 0.001, ηp 2 ≥ 0.42). Pairwise comparison revealed notably lower values for both DJ jumping height and reactive strength index at post compared to pre (BFR: -7.4 ± 9.4%, noBFR: -4.2 ± 7.4%). No statistically significant mode × time interactions (p ≥ 0.36; ηp 2 ≤ 0.01) have been observed for balance testing. Low intensity cycling with BFR results in increased (p ≤ 0.01; SMD ≥ 0.72) mean heart rate (+14 ± 8bpm), maximal heart rate (+16 ± 12 bpm), lactate (+0.7 ± 1.2 mmol/L), perceived training intensity (+2.5 ± 1.6au) and pain scores (+4.9 ± 2.2au) compared to noBFR. BFR cycling induced acutely impaired DJ performance, but balance performance was not affected, compared to noBFR cycling. Heart rate, lactate, perceived training intensity, and pain scores were increased during BFR cycling.
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Ciclismo , Ácido Láctico , Adulto Joven , Femenino , Humanos , Estudios Cruzados , Frecuencia Cardíaca , DolorRESUMEN
Running on less predictable terrain has the potential to increase the stimulation of the neuromuscular system and can boost aerobic performance. Hence, the purpose of this study was to analyze the effects of trail versus road running on neuromuscular and endurance performance parameters in running novices. Twenty sedentary participants were randomly assigned to either a trail (TRAIL; n = 10) or road running (ROAD; n = 10) group. A supervised and progressive, moderate intensity, and work-load-matched 8 wk endurance running program on TRAIL or ROAD was prescribed (i.e., randomized). Static balance (BESS test), dynamic balance (Y-balance test), gait analysis (RehaGait test, with regard to stride time single task, stride length dual task, velocity single task), agility performance (t-test), isokinetic leg strength (BIODEX), and predicted VO2max were assessed in pre- and post-tests. rANOVA analysis revealed no significant time-group interactions. Large effect sizes (Cohen's d) for pairwise comparison were found for TRAIL in the BESS test (d = 1.2) and predicted (pred) VO2max (d = 0.95). Moderate effects were evident for ROAD in BESS (d = 0.5), stride time single task (d = 0.52), and VO2max predicted (d = 0.53). Possible moderate to large effect sizes for stride length dual task (72%), velocity single task (64%), BESS test (60%), and the Y-balance test left stance (51%) in favor of TRAIL occurred. Collectively, the results suggested slightly more beneficial tendencies in favor of TRAIL. Additional research is needed to clearly elucidate differences between TRAIL and ROAD, not only in novices but also in experienced exercisers.
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Carrera , Propiedades de Superficie , Humanos , Análisis de la Marcha , Resistencia Física/fisiología , Carrera/fisiologíaRESUMEN
Peak oxygen uptake (VO2peak) and speed at first (LT1, minimal lactate equivalent) and second lactate threshold (LT2 = LT1 +1.5â mmol·L-1) are crucial swimming performance surrogates. The present randomized controlled study investigated the effects of blood flow restriction (BFR) during low-intensity swimming (LiT) on VO2peak, LT1, and LT2. Eighteen male swimmers (22.7 ±3.0 yrs; 69.9 ±8.5â kg; 1.8 ±0.1â m) were either assigned to the BFR or control (noBFR) group. While BFR was applied during LiT, noBFR completed the identical LIT without BFR application. BFR of the upper limb was applied via customized pneumatic cuffs (75% of occlusion pressure: 135 ±10 mmHg; 8â cm cuff width). BFR training took place three times a week over 5 weeks (accumulated weekly net BFR training: 60â min·week-1; occlusion per session: 2-times 10â min·session-1) and was used exclusively at low intensities. VO2peak, LT1, and LT2 diagnostics were employed. Bayesian credible intervals revealed notable VO2peak improvements by +0.29 L·min-1 kg-1 (95% credible interval: -0.26 to +0.85 L·min-1 kg-1) when comparing BFR vs. noBFR. Speed at LT1 -0.01â m·s-1 (-0.04 to +0.02â m·s-1) and LT2 -0.01â m·s-1 (-0.03 to +0.02â m·s-1) did not change meaningfully when BFR was employed. Fifteen sessions of LIT swimming (macrocycle of 5â h over 5 weeks) with a weekly volume of 60â min with BFR application adds additional impact on VO2peak improvement compared to noBFR LIT swimming. Occasional BFR applications should be considered as a promising means to improve relevant performance surrogates in trained swimmers.HighlightsLow-intensity swimming with blood flow restricted (BFR) induced superior peak oxygen consumption adaptations compared to non-restricted swimming training over a 5-week lasting training periodBFR and non-BFR swimming training-induced similar adaptations regarding swimming speed at first and second lactate thresholdIn conclusion, BFR served as a feasible, promising and beneficial complementary training stimuli to traditional swimming training regarding oxygen consumption adaptations.
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Entrenamiento de Fuerza , Natación , Humanos , Masculino , Natación/fisiología , Teorema de Bayes , Flujo Sanguíneo Regional/fisiología , Consumo de Oxígeno/fisiología , Ácido Láctico , Músculo Esquelético/fisiologíaRESUMEN
BACKGROUND: Traditional meta-analyses with pairwise direct comparison revealed that a variety of exercise-based training interventions can prevent falls in community-dwelling older adults. This network meta-analysis adds value by comparing and ranking different exercise training strategies based on their effects on fall risk reductions determined by analysis of direct and indirect comparisons. METHODS: The studies included in this network meta-analysis were identified through a comprehensive search in five biomedical databases (PubMed, SportDiscus, CINAHL, Web of Science and EMBASE). We included (randomized) controlled trials (RCTs) that compared the occurance of fall events in older adults who received different interventional treatments. RESULTS: Seventy six comparisons from 66 RCTs with 47.420 (61% male / 39% female) participants aged 77 ± 4 (68 - 88) years were included in this network meta-analysis. The network model revealed low heterogeneity (I2 = 28.0, 95%CI 1.0 to 47.7%) and inconsistency (Q between designs = 15.1, p = 0.37). Postural control training was found to be most effective in preventing falls (Postural Control Training: (home): Risk Ratio (RR) = 0.66, 95%-CI [0.49; 0.88], P-score = 0.97;Postural Control Training: RR = 0.82, 95%-CI [0.75; 0.91], P-score = 0.82). Combined and multifactorial interventions also display a robust but smaller effect (RR = 0.88-0.93, P-score = 0.65-0.47). CONCLUSION: Physical activity that includes balance training presents itself to be the most effective. Multifactorial approaches are well investigated but could be slightly less effective than isolated postural control training.
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A rowing cycle is characterised by a stretch-shortening cycle (SSC) at the quadriceps femoris muscle-tendon unit (MTU) level. However, due to the associated decoupling between MTU and muscle fascicle length changes, it remains unclear whether a rowing cycle causes active stretch at the muscle level. Fifteen young, sub-elite, male rowers (19.5 ± 1.6â yr; 1.94 ± 0.06â m; 91.9 ± 5.4â kg; rowing experience: 7.5 ± 2.8â yr) performed randomised 60-s rowing intervals using a traditional style at a low (LiR) and high intensity (HiR) and a micro-pause style at a low intensity (MpR). Muscle activity, knee joint angles, and muscle fascicle length changes from the left-sided vastus lateralis (VL) muscle were quantified using surface electromyography, inertial measurement units, and B-mode ultrasound imaging, respectively. All rowing conditions showed active fascicle stretch during late knee flexion (p≤0.001, standardised mean difference (SMD) ≥0.72) and subsequent active fascicle shortening throughout knee extension. Active fascicle stretch duration, amplitude and velocity (rANOVA: p≤0.001, ηp2 = 0.49) were not significantly different (p≥0.174; SMD≤0.26) between LiR and MpR, but were significantly increased during HiR (p≤0.001; SMD≥0.70). The percentage of rowing cycles that involved active fascicle stretch (rANOVA: p≤0.001, ηp2 = 0.95; post-hoc: p≤0.001, SMD≥0.87) was also significantly higher for HiR (98.3 ±12.9%) compared with both LiR (65.0 ± 48.1%) and MpR (68.3 ± 46.9%). In conclusion, rowing involves SSC at the VL muscle fascicle level, but the amount of active stretch differs between rowing intensities, with the longest, largest, and fastest active stretch occurring during HiR. SSC-based mechanisms may therefore contribute more to rowing performance during HiR than LiR or MpR.HighlightsSurface electromyography and ultrasound imaging revealed stretch-shortening cycles (SSCs) of the vastus lateralis muscle fascicles during rowingIncreased active fascicle stretch duration, amplitude and velocity from low- to high-intensity rowing indicate that SSC-based mechanisms likely contribute more to performance during high-intensity rowingThe SSC within the vastus lateralis muscle was independent of the rowing style at the same low rowing intensity.
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Músculo Cuádriceps , Deportes Acuáticos , Humanos , Masculino , Músculo Cuádriceps/diagnóstico por imagen , Músculo Cuádriceps/fisiología , Electromiografía , Contracción Muscular/fisiología , Músculo Esquelético/diagnóstico por imagen , Músculo Esquelético/fisiología , UltrasonografíaRESUMEN
In young and middle-aged adults, executive function is associated with success in work-life and mental health. Physical activity with and without cognitive training has the potential to benefit executive function, but its relative effectiveness remains unclear. This network meta-analysis compares the effectiveness of different exercise and cognitive training types and their combination on executive function in young and middle-aged adults. PubMed, Web of Science, MEDLINE, Cochrane, PsycINFO, and SPORTDiscus were searched for experimental studies that compared pre- to posttest changes in inhibitory control and/ or working memory between one or more intervention groups and a control group. Interventions were ranked on their relative effectiveness using P-scores. Study quality was rated using the PEDro scale. Forty-six studies were included and yielded 30 and 70 pair-wise effect sizes for the inhibitory control and working memory networks, respectively. With one exception, all studies were of high quality. Combined exercise and working memory training induced the greatest benefits for working memory (standardized mean differences, SMD = 0.59), whereas training a single executive function (SMD = 0.32) was most effective for inhibitory control. The effectiveness of working memory training (SMD ≥ 0.27) and coordinative exercise (SMD ≥ 0.20-0.29) ranked second and third for both executive function outcomes. In contrast, the effectiveness of endurance exercise was comparable to active controls on both networks. In young and middle-aged adults, exercise with coordinative demands seems to have an effectiveness similar to working memory training. The combination of exercise and cognitive training further increases executive function benefits.HighlightsDespite a developmental peak of executive function in young adulthood, this cognitive domain can be trained by exercise and cognitive trainingExercise with coordinative demands and working memory training benefit inhibitory control and working memory to a similar extentThe combination of exercise and working memory training elicited even greater benefits for working memoryYoung and middle-aged adults cannot expect executive function benefits following endurance exercise.
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Entrenamiento Cognitivo , Función Ejecutiva , Persona de Mediana Edad , Humanos , Adulto , Adulto Joven , Metaanálisis en Red , Ejercicio Físico , Terapia por EjercicioRESUMEN
The combination of plyometric and resistance training (RT) is frequently used to increase power-related adaptations. Since plyometric training is most effective when athletes are in a well-rested state, the acute effect of RT on plyometric performance should be carefully considered. Thus, 15 highly trained males (23.1±3.5 yrs, 1.80±0.06 m, 79.1±7.9 kg) completed a load- and volume-matched velocity-based RT session with 10% velocity loss (VL10) and traditional 1-repetition maximum-based RT session to failure (TRF) in a randomized order. Repeated sprints (5 × 15 m), countermovement jumps (CMJs), and drop jumps (DJs) were measured before, immediately after, and 24 h after both sessions. Lactate, heart rate, and perceived effort (RPE) were measured. Sprint, CMJ, and DJ revealed significant interaction effects (rANOVA p<0.001, ηp 2≥0.63). Immediately afterward, sprint, DJ, and CMJ were less negatively affected (p≤0.03, SMD≥|0.40|) by VL10 vs. TRF. Sprint and CMJ were already recovered 24 h post-testing and showed no significant differences between TRF and VL10 (p≥0.07, SMD≤|0.21|). Twenty-four hours post-testing, DJs were still reduced during TRF but already recovered during VL10 (p=0.01, SMD=|0.70|). TRF resulted in higher lactate, heart rate, and RPE compared to VL10 (p≤0.019, η p 2≥0.27, SMD≥|0.68|). In conclusion, the non-failure-based VL10 impairs jump and sprint performance less than the failure-based TRF approach, despite matched volume and intensity.