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ABSTRACT: Bauer, P, Majisik, A, Mitter, B, Csapo, R, Tschan, H, Hume, P, Martínez-Rodríguez, A, and Makivic, B. Body composition of competitive bodybuilders: a systematic review of published data and recommendations for future work. J Strength Cond Res 37(3): 726-732, 2023-The purpose of this review was to systematically summarize studies measuring the body composition of competitive bodybuilding athletes to provide recommended values for preparation and during competition. The protocol was preregistered with PROSPERO (CRD42020197921) and followed the guidelines of the Preferred Reported Items for Systematic Reviews and Meta-Analysis. A search of 5 electronic databases (PubMed, Web of Science, SportDiscus, CINAHL, and Scopus) was conducted to retrieve all relevant publications from January 1, 2000, up to June 13, 2021. Of 16 studies meeting the inclusion criteria, 6 presented longitudinal data on competition preparation and were discussed in detail. In the general preparation phase, body fat levels of bodybuilding athletes ranged between 15.3 and 25.2% (female) and from 9.6 to 16.3% (male). Close to competition, however, body fat levels were substantially lower, ranging from 8.1 to 18.3% for female and 5.8-10.7% for male athletes. All studies comparing relative body fat values at various time points during competition preparation found significant reductions between 30 and 60% in relative body fat, whereas lean mass was mostly maintained. Findings from the studies included in this review suggest that most bodybuilding competitors keep resistance training volume high while increasing aerobic training volume when preparing for competition. Findings on energy intake and macronutrient distribution were unclear and should be addressed in future studies. Further research, especially on contest preparation, is warranted and should include more details about training programs, nutritional strategies, psychosocial situation, anabolic androgen steroid, and supplement use as well as measurement protocols and preparation.
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Composición Corporal , Ingestión de Energía , Humanos , Masculino , Femenino , Suplementos Dietéticos , Tejido Adiposo/metabolismoRESUMEN
ABSTRACT: Hauer, R, Tessitore, A, Hauer, K, and Tschan, H. Activity profile of international female lacrosse players. J Strength Cond Res 35(11): 3207-3212, 2021-This study was designed to investigate the activity profile in international women's lacrosse match-play. Data were collected of 10 female Austrian lacrosse national team players (29.1 ± 6.1 years; 64.2 ± 5.0 kg; and 165.3 ± 4.1 cm) during 4 games of an international tournament using global positioning system and heart rate monitor devices. The mean average heart rate was 75.3 ± 5.0% of maximum heart rate (HRmax) with 23 ± 6.1% of total playing time spent in HRzone 4 (80-90% of HRmax). The mean distance covered during match-play was 3,791.6 ± 554.5 m, of which 38 ± 6.5% were performed in speed zone 1 (<7.0 km·h-1). Ten ±4 sprints per game were conducted with 55 ± 3.8% of accelerations and 59 ± 3.1% of decelerations in zone 1, respectively. Defenders showed greater total distance covered compared with other positions (attack: p = 0.035; d = 0.87; confidence interval [CI] = 0.18-1.56 and midfield: p = 0.006; d = 1.66; CI = 0.93-2.40). Midfielders covered less distance in speed zone 1 (p = 0.032; d = 1.91; CI = 0.53-3.28) compared with attackers, and lower numbers of accelerations (p = 0.042; d = 0.96; CI = 0.20-1.72) and decelerations (p = 0.021; d = 1.79; CI = 0.61-2.97) in zone 3 compared with defenders. Furthermore, attackers showed less distance covered in speed zone 1 (p = 0.09; d = 1.62; CI = 0.86-2.38) compared with defenders. The provided activity data could help coaches and practitioners in designing competition-specific programs for athletes. In addition, positional differences should be taken into account for tactical and physiological aspects.
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Rendimiento Atlético , Deportes de Raqueta , Carrera , Aceleración , Rendimiento Atlético/fisiología , Femenino , Sistemas de Información Geográfica , Humanos , Deportes de Raqueta/fisiología , Carrera/fisiologíaRESUMEN
ABSTRACT: Mitter, B, Hölbling, D, Bauer, P, Stöckl, M, Baca, A, and Tschan, H. Concurrent validity of field-based diagnostic technology monitoring movement velocity in powerlifting exercises. J Strength Cond Res 35(8): 2170-2178, 2021-The study was designed to investigate the validity of different technologies used to determine movement velocity in resistance training. Twenty-four experienced powerlifters (18 male and 6 female; age, 25.1 ± 5.1 years) completed a progressive loading test in the squat, bench press, and conventional deadlift until reaching their 1 repetition maximum. Peak and mean velocity were simultaneously recorded with 4 field-based systems: GymAware (GA), FitroDyne (FD), PUSH (PU), and Beast Sensor (BS). 3D motion capturing was used to calculate specific gold standard trajectory references for each device. GA provided the most accurate output across exercises (r = 0.99-1, ES = -0.05 to 0.1). FD showed similar results for peak velocity (r = 1, standardized mean bias [ES] = -0.1 to -0.02) but considerably less validity for mean velocity (r = 0.92-0.95, ES = -0.57 to -0.29). Reasonably valid to highly valid output was provided by PU in all exercises (r = 0.91-0.97, ES = -0.5 to 0.28) and by BS in the bench press and for mean velocity in the squat (r = 0.87-0.96, ES = -0.5 to -0.06). However, BS did not reach the thresholds for reasonable validity in the deadlift and for peak velocity in the squat, mostly due to high standardized mean bias (ES = -0.78 to -0.63). In conclusion, different technologies should not be used interchangeably. Practitioners who require negligible measurement error in their assessment of movement velocity are advised to use linear position transducers over inertial sensors.
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Entrenamiento de Fuerza , Levantamiento de Peso , Adulto , Femenino , Humanos , Masculino , Fuerza Muscular , Reproducibilidad de los Resultados , Tecnología , Adulto JovenRESUMEN
Previous studies reported faster pulmonary oxygen uptake kinetics at the onset of exercise in untrained youth compared with adults. Whether or not these differences are identical for trained groups have not been examined. The purpose of this study was to compare ËVO2 kinetics of youth and adult cyclists at moderate and heavy-intensity exercise. Thirteen adult (age: 23.2 ± 4.8 years; ËVO2peak 68.4 ± 6.8 mL·min-1.kg-1) and thirteen youth cyclists (age: 14.3 ± 1.5 years; ËVO2peak 61.7 ± 4.3 mL·min-1.kg-1) completed a series of 6-min square wave exercises at moderate and heavy-intensity exercise at 90 rev·min-1. A two-way repeated-measure ANOVA was conducted to identify differences between groups and intensities. The time constant, time delay and the mean response time were not significantly different between youth and adult cyclists (p > 0.05). We found significant differences between intensities, with a faster time constant during moderate than heavy-intensity exercise in youth (24.1 ± 7.0 s vs. 31.8 ± 5.6 s; p = 0.004) and adults (22.7 ± 5.6 s vs. 28.6 ± 5.7 s; p < 0.001). The present data suggest that the effect of training history in adult cyclists compensate for the superior primary response of the oxygen uptake kinetics typically seen in youth compared to adults. Furthermore, the ËVO2 response is dependent of work rate intensity in trained youth and adult cyclists.
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Ciclismo/fisiología , Entrenamiento Aeróbico , Consumo de Oxígeno , Adaptación Fisiológica , Adolescente , Adulto , Factores de Edad , Femenino , Humanos , Cinética , Masculino , Adulto JovenRESUMEN
Sansone, P, Tschan, H, Foster, C, and Tessitore, A. Monitoring training load and perceived recovery in female basketball: Implications for training design. J Strength Cond Res 34(10): 2929-2936, 2020-This study investigated the relationship between internal training load and perceived recovery of semi-professional female basketball players during the competitive season. Eleven female players were monitored for 14 weeks during the in-season phase. For each event (training and game), data were collected as follows: (a) Total Quality Recovery (TQR) score before the event (TQRpre); (b) session Rating of Perceived Exertion (sRPE) 20 minutes after completion of the event, to calculate training load (s-TL) of the event; and (c) TQR scores 12 (TQRpost12) and 24 hours (TQRpost24) after the event. Data were analyzed for daily, weekly, and mesocycle (regular season; regional play-off; and national play-off) time frames. Daily analysis showed that: TQRpost12 was lower than TQRpre (p < 0.001) and TQRpost24 (p < 0.001); s-TL had a moderate negative correlation with TQRpost12 (r = -0.48, p = 0.002); the difference between TQRpre and RPE (TS-Δ) had a very large positive correlation with TQRpost12 (r = 0.70, p < 0.001); and TQRpost24 was not significantly correlated with training parameters. Weekly analysis highlighted a very large negative correlation between the acute:chronic workload ratio and TQR collected at the start of the following week (TQRfw) (r = -0.86, p < 0.001). Finally, although weekly TL and TQRfw did not differ between mesocycles, their correlation increased in the later seasonal phases. This study demonstrated negative relationships between training load and recovery of semi-professional female basketball players at daily, weekly, and mesocycle levels. Therefore, concurrently monitoring training and recovery with the sRPE method and TQR scale is recommended for designing training schedules in basketball.
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Baloncesto/fisiología , Acondicionamiento Físico Humano/fisiología , Esfuerzo Físico/fisiología , Adolescente , Adulto , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Acondicionamiento Físico Humano/métodos , Estaciones del Año , Adulto JovenRESUMEN
This study aimed to evaluate the technical-tactical, perceptual and mental demands of basketball small-sided games (SSGs). Twelve male semi-professional players participated in four half-court 3vs3 SSGs characterized by different tactical tasks (offensive; defensive) and training regimes (long-intermittent; short-intermittent). The SSGs were video-recorded to perform notational analysis of technical-tactical parameters. Ratings of perceived exertion (RPE, CR-100 scale), mental effort (ME) and e njoyment were collected after completion of each SSG. Before and after the SSGs, players reported their perceived mental fatigue (MF); for this indicator, the difference between post- and pre-SSG values was calculated (ΔMF). Notational analysis evidenced a higher volume of play (ball possessions, ball possessions per minute) [large effect size (ES)], dribbles and shot attempts (moderate ES) in short-intermittent regimes compared to long-intermittent. Two-way (tactical task; training regime) repeated-measures ANOVA showed an interaction effect for RPE (moderate ES). Players reported that playing the offensive task required higher mental effort compared to playing defence (moderate ES), while no differences for mental effort were found between regimes. Enjoyment did not differ between tasks or regimes. No effects were found for ΔMF, while this indicator was significantly correlated with RPE scores (r= 0.50, large). This study suggests that, in basketball SSGs, shorter regimes induce higher technical demands, while tactical tasks influence perceived exertion responses and mental effort. Furthermore, perceived exertion appears significantly associated with variations of mental fatigue induced by training drills.
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The O2-kinetic response to constant work rate exercise provides an insight into the adjustment of systemic oxygen transport and muscle metabolism. Whether O2-kinetics measured in laboratory conditions reflect O2-kinetics in field conditions has not yet been analysed. The aim of this study was to compare O2-kinetics between field and laboratory conditions. Thirteen competitive male cyclists (mean±SD age 23.3±4.1 years; VÌO2peak 68.2±4.7 mL.min-1.kg-1) completed two 6-min severe-intensity trials at 60 and 90 rev.min-1 in both conditions. Power output was measured with an SRM power meter and VÌO2 was measured with a portable gas analyser. The time constant (τ), the time delay (TD) and the amplitude (Amp) were resolved by least square regression, and the VÌO2 slow component (SC) was calculated as the difference between the end-exercise VÌO2 and Amp. To determine differences between the trials, a repeated-measure ANOVA was conducted. The Amp and end-exercise VÌO2 were significantly higher during field cycling whereas the SC were significantly higher during laboratory cycling (all at p<0.001). No significant differences were found for τ (p=0.24). Laboratory measures tend to underestimate the oxygen demand in field cycling. A higher cadence leads to greater oxygen demand in laboratory and field cycling.
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Ciclismo/fisiología , Consumo de Oxígeno , Adulto , Prueba de Esfuerzo , Humanos , Masculino , Adulto JovenRESUMEN
Bauer, P, Sansone, P, Mitter, B, Makivic, B, Seitz, LB, and Tschan, H. Acute effects of back squats on countermovement jump performance across multiple sets of a contrast training protocol in resistance-trained men. J Strength Cond Res 33(4): 995-1000, 2019-This study was designed to evaluate the voluntary postactivation potentiation (PAP) effects of moderate-intensity (MI) or high-intensity (HI) back squat exercises on countermovement jump (CMJ) performance across multiple sets of a contrast training protocol. Sixty resistance-trained male subjects (age, 23.3 ± 3.3 years; body mass, 86.0 ± 13.9 kg; and parallel back squat 1-repetition maximum [1-RM], 155.2 ± 30.0 kg) participated in a randomized, crossover study. After familiarization, the subjects visited the laboratory on 3 separate occasions. They performed a contrast PAP protocol comprising 3 sets of either MI (6 × 60% of 1-RM) or HI back squats (4 × 90% of 1-RM) or 20 seconds of recovery (CTRL) alternated with 7 CMJs that were performed at 15 seconds, and 1, 3, 5, 7, 9 and 11 minutes after the back squats or recovery. Jump height and relative peak power output recorded with a force platform during MI and HI conditions were compared with those recorded during control condition to calculate the voluntary PAP effect. Countermovement jump performance was decreased immediately after the squats but increased across all 3 sets of MI and HI between 3 and 7 minutes after recovery. However, voluntary PAP effects were small or trivial, and no difference between the 3 sets could be found. These findings demonstrate that practitioners can use MI and HI back squats to potentiate CMJs across a contrast training protocol, but a minimum of 3 minutes of recovery after the squats is needed to benefit from voluntary PAP.
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Rendimiento Atlético/fisiología , Movimiento , Fuerza Muscular , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Adulto , Estudios Cruzados , Prueba de Esfuerzo , Humanos , Masculino , Distribución Aleatoria , Recuperación de la Función , Factores de Tiempo , Adulto JovenRESUMEN
BACKGROUND: High physical fitness levels in childhood and adolescence are associated with positive health-related outcomes later in life. Albeit many researchers investigated rural-urban differences in physical fitness, the outcomes of these studies are inconsistent and data on Kosovo are widely missing. Thus, this study aims to examine anthropometric and physical fitness parameters in 14 to 15 year old Kosovan adolescents living in rural and urban areas. METHODS: Two schools from Pristina (mostly urban population) and two schools in the surrounding villages of the district of Deçan (mostly rural population) were selected. Anthropometric and physical fitness parameters were determined from a total of 354 adolescents (216 urban: 14.5 ± 0.4 years, 138 rural: age 14.5 ± 0.4 years) who volunteered to participate in this cross-sectional study performed in 2013/14. RESULTS: The prevalence of overweight and obesity was 18.9% in girls and 28.2% in males and excess body fat was detected in 18.2% of the girls and 15.9% of the boys with no differences between rural and urban adolescents. Rural adolescents performed slightly better in relative handgrip strength (+4.7%, p = 0.032) and running speed (10 m: +2.2%, p = 0.012; 20 m: +1.9%, p = 0.035), but no other differences were detected in standing long jump, counter movement jump, cardiorespiratory fitness and sit and reach test. A multinomial logistic regression analysis revealed that being a female was associated with a lower relative risk for overweight (RR = 0.11, 95% CI: 0.03-0.34, p < 0.001) and high body fat content (RR = 0.20, 95% CI: 0.05-0.56, p < 0.001). In addition, higher handgrip strength, longer sprinting time and lower aerobic fitness were associated with a higher relative risk for overweight and excess body fat. In contrast, lower handgrip strength increased the risk for experiencing thinness (RR = 0.92, 95% CI: 0.89-0.96, p < 0.001). CONCLUSIONS: It could be shown that there is a high prevalence of overweight and obesity, especially in 14 to 15 year old boys in Kosovo which does not differ between rural and urban areas. Worse physical performance is associated with a higher risk for overweight and obesity highlighting the importance for interventions in this area and for starting longitudinal observations of a secular trend.
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Antropometría , Obesidad Infantil/epidemiología , Aptitud Física , Población Rural/estadística & datos numéricos , Población Urbana/estadística & datos numéricos , Adolescente , Estudios Transversales , Femenino , Humanos , Kosovo/epidemiología , Masculino , Prevalencia , Factores de Riesgo , Distribución por SexoRESUMEN
Whilst Critical Speed (CS) has been successfully translated from the laboratory into the field, this translation is still outstanding for the related maximum running distance (D'). Using iso-duration exhaustive laboratory and field runs, this study investigated the potential interchangeable use of both parameters, D' and CS. After an incremental exercise test, 10 male participants (age: 24.9±2.1 yrs; height: 180.8±5.8 cm; body mass: 75.3±8.6 kg; VÌ ËVO2peak 52.9±3.1 mLâmin-1âkg-1) performed 3 time-to-exhaustion runs on a treadmill followed by 3 exhaustive time-trial runs on a-400 m athletics outdoor track. Field time-trial durations were matched to their respective laboratory time-to-exhaustion runs. D' and CS were calculated using the inverse-time model (speed=D'/t+CS). Laboratory and field values of D' and CS were not significantly different (221±7 m vs. 225±72 m; P=0.73 and 3.75±0.36 mâs-1 vs. 3.77±0.35 mâs-1, P=0.68), and they were significantly correlated (r=0.86 and 0.94). The 95% LoA were ±75.5 m and ±0.24 mâs-1 for D' and CS, respectively. Applying iso-durations provides non-significant differences for D' and CS and a significant correlation between conditions. This novel translation method can consequently be recommended to coaches and practitioners, however a questionable level of agreement indicates to use D' with caution.
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Prueba de Esfuerzo/métodos , Resistencia Física/fisiología , Carrera/fisiología , Adulto , Humanos , Masculino , Adulto JovenRESUMEN
PURPOSE: Regular resistance exercise training and a balanced diet may counteract the age-related muscular decline on a molecular level. The aim of this study was to investigate the influence of elastic band resistance training and nutritional supplementation on circulating muscle growth and degradation factors, physical performance and muscle quality (MQ) of institutionalized elderly. METHODS: Within the Vienna Active Ageing Study, 91 women aged 83.6 (65.0-92.2) years were randomly assigned to one of the three intervention groups (RT, resistance training; RTS, resistance training plus nutritional supplementation; CT, cognitive training). Circulating levels of myostatin, activin A, follistatin, IGF-1 and GDF-15, as well as MQ and functional parameters were tested at baseline as well as after 3 and 6 months of intervention. RESULTS: MQ of lower extremities significantly increased in the RT group (+14 %) and RTS group (+12 %) after 6 months. Performance improved in the RT and RTS groups for chair stand test (RT: +18 %; RTS: +15 %). Follistatin increased only in the RT group (+18 %) in the latter phase of the intervention, accompanied by a decrease in the activin A-to-follistatin ratio (-7 %). IGF-1, myostatin and GDF-15 levels were not affected by the intervention. CONCLUSION: Our data confirm that strength training improves physical performance and MQ even in very old institutionalized women. This amelioration appears to be mediated by blocking muscle degradation pathways via follistatin rather than inducing muscle growth through the IGF-1 pathway. As plasma levels of biomarkers reflect an overall status of various organ systems, future studies of tissue levels are suggested.
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Envejecimiento/fisiología , Ejercicio Físico/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Activinas/sangre , Anciano , Anciano de 80 o más Años , Envejecimiento/sangre , Envejecimiento/metabolismo , Suplementos Dietéticos , Femenino , Folistatina/sangre , Factor 15 de Diferenciación de Crecimiento/sangre , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Músculo Esquelético/metabolismo , Miostatina/sangreRESUMEN
BACKGROUND: This observational, cross-sectional study investigates the impact of medication usage, physical activity (PA) and nutritional status on musculoskeletal health (MSH) in males and females aged 40-65 in the population of a post conflict, developing country. METHODS: Bone Mineral Density (BMD), T-score and Z-score at distal forearm regions (measured by DEXA scan), together with isometric hand grip strength (dynamometer) were evaluated in a total of 162 subjects (53 Males, average age 55.15±7.12 and 109 Females, 54.27±5.1). Additionally, bio-anthropometric assessments, medication usage, PA level and nutritional status were assessed. RESULTS: Significant differences (p<0.05) were found in total subjects Body Mass Index (BMI), PA, BMD, T-score and Hand grip between genders. 42% of total participants met the diagnostic criteria of, out of which 6.8% with T-score below -2, while no cases of Osteoporosis was recorded. N05B Anxiolytics and A02B Drugs for peptic ulcer and gastro-oesophageal reflux disease medication groups consumption turned to have no significant differences (p>0.05) in BMD, T-score, and hand grip in total population, except for A02B where p<0.05 were found in Hand grip, as well as between female consumers and no consumers in all variables. Meanwhile, in total subjects consuming H02AB Glucocorticoids p<0.05 were observed in BMD and T-score, but not on hand grip. CONCLUSIONS: This study shows a low risk for MSH problems amongst the studied population in Kosova, while the consumption of H02AB medication group in both genders and A02B in females only for extended periods might effect MSH, therefore appropriate benefit/risk assessment should be made before prescribing these medications, notwithstanding age, gender, PA or nutritional status.
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Estilo de Vida , Enfermedades Musculoesqueléticas/epidemiología , Adulto , Anciano , Densidad Ósea , Estudios Transversales , Ejercicio Físico , Femenino , Fuerza de la Mano , Estado de Salud , Humanos , Kosovo , Masculino , Persona de Mediana Edad , Sistema Musculoesquelético/efectos de los fármacos , Estado NutricionalRESUMEN
The TGF-ß superfamily has been shown to play an important role in a wide range of physiological as well as pathological processes including ageing, immune modulation, atherosclerosis and cancer development. The aim of the current study was to investigate (i) whether TGF-ß signalling in peripheral blood mononuclear cells (PBMCs) would differ between young and old females and (ii) whether physical performance parameters of elderly women would be related to the expression of TGF-ß or its receptors. Sixteen healthy young (22-28 years; YF) and 90 healthy older (65-92 years; OF) females participated in the study. In addition to several components of health-related physical fitness, circulating CRP and TGF-ß levels were determined together with the mRNA expression of TGF-ß, TGF-ßRI, TGF-ßRII, and miRNA-21 (known to interfere with TGF-ß signalling) in PBMCs. Physical fitness as determined by 6-minutes walking test (YF:median 932 (range 573-1254) m; OF:360 (114-558) m), handgrip strength (YF: 32 (24-39) kg; OF:18(10-30) kg), relative isokinetic peak torque of knee extensors (YF:1.9 (1.2- 2.3) Nm/kg; OF:1.0 (0.2-1.9) Nm/kg and flexors (YF: 1.1 (0.7- 1.5) Nm/kg; OF: 0.5 (0.2-1.0) Nm/kg was substantially lower in older women (p<0.001 for all comparisons). These changes were paralleled by an increase in hs-CRP (YF: 0.9 (0.1-4.3)mg/L; OF: 2.3 (0.3-56.7)mg/L,p<0.001). Serum levels of TGF-ß and TGF-ß mRNA levels from PBMCs did not differ between young and old women whereas, both TGF- ßRI/GAPDH (YF: 4.07 (1.38-14.60); OF: 2.08 (0.14-28.81); p=0.020) and TGF-ßRII/GAPDH levels (YF: 3.16 (1.14- 10.25); OF: 1.71 (0.51-14.86); p=0.020) were lower with respect to old age. In elderly women, only TGF-ßRΙ expression correlated negatively with miRNA-21 expression in PBMCs (ρ=-0.315; p=0.004). Interestingly, hs-CRP and miRNA correlated positively with handgrip strength (ρ=0.237 and ρ=243, p<0.05), while none of the TGF-ß-related parameters were related to physical performance. The results suggest that age affects TGF-ß signalling in leukocytes by altering the expression levels of its receptors. These changes seem to occur independently of physical fitness of old women.
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Envejecimiento/fisiología , Regulación de la Expresión Génica/fisiología , Leucocitos/metabolismo , MicroARNs/sangre , Aptitud Física/fisiología , Factor de Crecimiento Transformador beta/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/sangre , Envejecimiento/inmunología , Composición Corporal , Proteína C-Reactiva/análisis , Femenino , Voluntarios Sanos , Humanos , Resistencia Física/fisiología , ARN Mensajero/sangre , Rango del Movimiento Articular , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/fisiología , Factor de Crecimiento Transformador beta/genética , Caminata , Adulto JovenRESUMEN
The usage of the oral contraceptive pill is widespread among athletes of various levels. However, there is limited knowledge on how the intake of the pill alters the submaximal and maximal endurance parameters between the oral contraceptive phases. Therefore, the aim of this study was to examine potential differences between the pill intake and withdrawal phase on endurance-related parameters in first-division handball players. In total, 15 female team handball players performed two graded exercise tests until volitional exhaustion on a motorized treadmill. Tests were performed during the pill intake (days 16-17) and withdrawal phase (day 2-3). Throughout the test, respiratory gases were measured breath-by-breath, and the heart rate was measured continuously. Before and after the graded exercise test, blood samples were obtained in order to assess the blood lactate concentration. Before each test, venous blood samples were taken to determine endogenous sex hormone levels. Ventilatory parameters (VËO2, VËCO2, and VËE, and respiratory equivalents for VËO2 and VËCO2) were measured, and the oxidation of fat and carbohydrates was calculated. A paired-sample t-test was used to assess differences between the two time points, and the significance was accepted as p < 0.050. Significant differences with lower values during the consumption phase were found for absolute (mean difference ± SD: 88 ± 131 mLâmin-1; p = 0.021) and relative VËO2peak (mean difference ± SD: 1 ± 2 mLâmin-1âkg-1; p = 0.012). Higher values during the consumption phase were found for submaximal respiratory equivalents for VËO2 (mean difference ± SD: -1.1 ± 1.7; p = 0.028) and VËCO2 (mean difference ± SD: -0.9 ± 1.5; p = 0.032). No differences were found for all other parameters, including differences for endogenous sex hormones (p > 0.050). The results of the current study suggest only marginal and physiologically insignificant differences in endurance-related parameters between oral contraceptive phases.
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To identify the relationship between load and the number of repetitions performed to momentary failure in the pin press exercise, the present study compared different statistical model types and structures using a Bayesian approach. Thirty resistance-trained men and women were tested on two separate occasions. During the first visit, participants underwent assessment of their one-repetition maximum (1-RM) in the pin press exercise. On the second visit, they performed sets to momentary failure at 90%, 80% and 70% of their 1-RM in a fixed order during a single session. The relationship between relative load and repetitions performed to failure was fitted using linear regression, exponential regression and the critical load model. Each model was fitted according to the Bayesian framework in two ways: using an across-subjects pooled data structure and using a multilevel structure. Models were compared based on the variance explained (R2) and leave-one-out cross-validation information criterion (LOOIC). Multilevel models, which incorporate higher-level commonalities into individual relationships, demonstrated a substantially better fit (R2: 0.97-0.98) and better predictive accuracy compared to generalised pooled-data models (R2: 0.89-0.93). The multilevel 2-parameter exponential regression emerged as the best representation of data in terms of model fit, predictive accuracy and model simplicity. The relationship between load and repetitions performed to failure follows an individually expressed exponential trend in the pin press exercise. To accurately predict the load that is associated with a certain repetition maximum, the relationship should therefore be modelled on a subject-specific level.
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Músculo Esquelético , Entrenamiento de Fuerza , Masculino , Humanos , Femenino , Teorema de Bayes , Levantamiento de Peso , Ejercicio Físico , Fuerza MuscularRESUMEN
The aim of the study was to investigate the independent relationship between maximal lactate steady state (MLSS), blood lactate concentration [La] and exercise performance as reported frequently. Sixty-two subjects with a wide range of endurance performance (MLSS power output 199 ± 55 W; range: 100-302 W) were tested on an electronically braked cycle ergometer. One-min incremental exercise tests were conducted to determine maximal variables as well as the respiratory compensation point (RCP) and the second lactate turn point (LTP2). Several continuous exercise tests were performed to determine the MLSS. Subjects were divided into three clusters of exercise performance. Dietary control was employed throughout all testing. No significant correlation was found between MLSS [La] and power output at MLSS. Additionally, the three clusters of subjects with different endurance performance levels based on power output at MLSS showed no significant difference for MLSS [La]. MLSS [La] was not significantly different between men and women (average of 4.80 ± 1.50 vs. 5.22 ± 1.52 mmol l(-1)). MLSS [La] was significantly related to [La] at RCP, LTP2 and at maximal power. The results of this study support previous findings that MLSS [La] is independent of endurance performance. Additionally, MLSS [La] was not influenced by sex. Correlations found between MLSS [La] and [La] at maximal power and at designated anaerobic thresholds indicate only an association of [La] response during incremental and MLSS exercise when utilizing cycle ergometry.
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Tolerancia al Ejercicio , Ácido Láctico/sangre , Contracción Muscular , Músculo Esquelético/metabolismo , Resistencia Física , Recreación , Adulto , Umbral Anaerobio , Análisis de Varianza , Ciclismo , Biomarcadores/sangre , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Consumo de Oxígeno , Respiración , Factores Sexuales , Factores de Tiempo , Adulto JovenRESUMEN
The present study was designed to evaluate the test-retest consistency of repetition maximum tests at standardized relative loads and determine the robustness of strength-endurance profiles across test-retest trials. Twenty-four resistance-trained males and females (age, 27.4 ± 4.0 y; body mass, 77.2 ± 12.6 kg; relative bench press one-repetition maximum [1-RM], 1.19 ± 0.23 kgâ¢kg-1) were assessed for their 1-RM in the free-weight bench press. After 48 to 72 hours, they were tested for the maximum number of achievable repetitions at 90%, 80% and 70% of their 1-RM. A retest was completed for all assessments one week later. Gathered data were used to model the relationship between relative load and repetitions to failure with respect to individual trends using Bayesian multilevel modeling and applying four recently proposed model types. The maximum number of repetitions showed slightly better reliability at lower relative loads (ICC at 70% 1-RM = 0.86, 90% highest density interval: [0.71, 0.93]) compared to higher relative loads (ICC at 90% 1-RM = 0.65 [0.39, 0.83]), whereas the absolute agreement was slightly better at higher loads (SEM at 90% 1-RM = 0.7 repetitions [0.5, 0.9]; SEM at 70% 1-RM = 1.1 repetitions [0.8, 1.4]). The linear regression model and the 2-parameters exponential regression model revealed the most robust parameter estimates across test-retest trials. Results testify to good reproducibility of repetition maximum tests at standardized relative loads obtained over short periods of time. A complementary free-to-use web application was developed to help practitioners calculate strength-endurance profiles and build individual repetition maximum tables based on robust statistical models.
Asunto(s)
Entrenamiento de Fuerza , Levantamiento de Peso , Adulto , Teorema de Bayes , Terapia por Ejercicio , Femenino , Humanos , Masculino , Fuerza Muscular , Músculo Esquelético , Estado Nutricional , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
Mental fatigue can impair physical, technical, and tactical performance in sports. Since most previous research used general cognitive tasks to elicit mental fatigue, the aim of this study was to investigate whether a more sport-specific task could induce the effects of mental fatigue and impair the subsequent physical and technical performance in a soccer small-sided game. Ten soccer players performed two small-sided games on two different days in a crossover design. Before each small-sided game, they performed a video-based tactical task (30 min) and a control task (documentary watching, 30 min) in a randomized and counterbalanced order. Mental effort was measured through a visual analog scale after the tactical and control tasks. Subjective ratings of perceived exertion were assessed through the RPE questionnaire after the end of the SSG. Physical performance was assessed during the SSG through GPS technology. Results showed no differences (p > 0.05) in physical performance between the two conditions. None of the technical variables were negatively affected by the video-based tactical condition, with the number of total passes (p = 0.003; ES = 0.72 medium) and successful passes (p = 0.003; ES = 0.82 large) results even improved by the video-based tactical task. The mental effort required by the video-tactical task was significantly higher than the control task (p = 0.002; ES = 2.09 huge). However, overall RPE did not differ between conditions. The video-based tactical task did not elicit mental fatigue and did not impair subsequent physical and technical performance. The higher ecological validity of the task and the higher motivation of the participants might have contributed to the results.
RESUMEN
Agility and change of direction speed are two different abilities, but no study has investigated if this difference exists also in fatigued conditions, and whether fatigue develops in a different way in a repeated-trial scenario. Fourteen soccer players (age: 17.0 ± 0.4 yrs; height: 176.9 ± 6.5 cm; body mass: 69.2 ± 6.4 kg) competing in a national-level youth league completed in a randomized counter-balanced crossover design a repeated agility protocol (RA) and a repeated change-of-direction one (RCOD), both consisting in performing 20 consecutive repetitions (work:rest ratio 1:5). The 20 repetitions were divided into 4 blocks (each block containing 5 repetitions) for the analysis. Results show that agility and COD are two different abilities both in rest and fatigue conditions: block 1 RA vs 1 RCOD (p < 0.001; ES = 2.02 huge; r = 0.17 poor; r2 = 0.03), 2 RA vs 2 RCOD (p < 0.001; ES = 2.3 huge; r = 0.51 fair; r2 = 0.26), 3 RA vs 3 RCOD (p < 0.001; ES = 2.38 huge; r = 0.54 fair; r2 = 0.29), and 4 RA vs 4 RCOD (p < 0.001; ES = 2.7 huge; r = 0.41 fair; r2 = 0.17). However, the fatigue development in both conditions was similar, with a percentage decrement score (Sdec) of 7.5% for RA, and 7.3% for RCOD. Ratings of perceived exertions (RPE) were similar too (7.3 ± 1.7, and 6.6 ± 1.9, for RA and RCOD, respectively). However, a significant fatigue-related performance impairment arose earlier in RA (block 2) than in RCOD (block 3). Total RA and total RCOD times were significantly different (p < 0.001; ES = 2.65 huge; r = 0.41 fair; r2 = 0.17), suggesting that they are two different and independent abilities.
Asunto(s)
Rendimiento Atlético , Carrera , Fútbol , Adolescente , Estudios Cruzados , Fatiga , HumanosRESUMEN
BACKGROUND: Time constraints comprise one limiting factor for implementing school-based physical activity programs. The aim of this pilot cluster randomized controlled study was to explore the effects of a cycle ergometer intervention during regular lessons on physical fitness, body composition, and health-related blood parameters. METHODS: Participants attended one of 2 classes selected from one school, which were randomly assigned to an intervention group (n = 23, 11.2 [0.5] y) consisting of cycling on classroom-based ergometers during 3 lessons per week at a self-selected intensity and a control group (n = 21, 11.3 [0.5] y) not receiving any treatment. Prior to and after the 5-month intervention period, physical fitness (with ventilatory threshold as primary outcome), body composition, and parameters of glucose and lipid metabolism were assessed. RESULTS: A significant time × group interaction was revealed for ventilatory threshold (P = .035), respiratory compensation point (P = .038), gross efficiency (P < .001), maximal aerobic power (P = .024), triglycerides (P = .041), and blood glucose levels (P = .041) with benefits for the intervention group. Peak oxygen uptake and body composition were not affected. CONCLUSIONS: Children's aerobic capacity benefited from the low-intensity school-based cycling intervention, while body composition and most blood parameters were not affected. The intervention using cycle ergometers is a feasible and time-saving strategy to elevate submaximal physical fitness.