In questo articolo riportiamo gli abstract originali di quelli che consideriamo i 4 articoli scientifici di maggior impatto pubblicati nelle riviste di scienze dello sport classificate come SCImago Q1 e Q2 nel mese di Novembre 2021. Questo è per condividere quelle che secondo noi sono le novità scientifiche più interessanti nell’ambito della preparazione atletica e performance sportiva. Gli articoli proposti sono stati selezionati a seguito di una ricerca condotta su google scholar digitando le seguenti parole chiave: Strength training”, “Resistance training”, “Endurance training”,” Sprint training”, “Aerobic training”, “Anaerobic training”.
- Girard, O., Mariotti-Nesurini, L., & Malatesta, D. (2021). Acute performance and physiological responses to upper-limb multi-set exercise to failure: effects of external resistance and systemic hypoxia: Local and systemic hypoxia combined. European Journal of Sport Science, (just-accepted), 1-28.
This study quantified performance and physiological responses during multi-set resistance exercise to failure at light versus moderate loads in normoxia and systemic hypoxia. On separate visits, fifteen resistance-trained adults performed barbell biceps curl exercise trials (6 sets to failure, 2 min rest between sets) in four separate randomized conditions; i.e., in normoxia at 380 m above sea level or systemic hypoxia at ∼3800 m simulated altitude (inspired oxygen fraction = 20.9% and 12.9%, respectively) combined with two different intensity levels (30% and 70% of 1 repetition maximal or 1RM). Muscle activation (root mean square value calculated from surface electromyography) and oxygenation (integrated-tissue saturation index derived from near-infrared spectroscopy) were monitored for the biceps brachii muscle. The total number of repetitions before failure at 30% 1RM (122 ± 5 vs. 131 ± 5; P=0.021), but not 70% 1RM (39 ± 1 vs. 41 ± 2; P=0.313), was lower in hypoxia compared to normoxia. Root mean square activity of the biceps brachii muscle was higher for 70% 1RM compared to 30% 1RM (P<0.001), while the increase in muscle activation from the first to the last set (P<0.001) occurred independently of altitude (P>0.158). Deoxygenation and reoxygenation responses were higher under hypoxic versus normoxic conditions at 70% 1 RM (P=0.013 and P=0.015) but not 30% 1RM (P=0.528 and P=0.384). During upper-limb multi-set resistance exercise to failure, exposure to acute normobaric hypoxia negatively impacts performance at light, but not moderate, loads. Overall, external resistance has more profound effects on physiological strain than hypoxic exposure per se.
https://doi.org/10.1080/17461391.2021.2002951
- Fyfe, J. J., Hamilton, D. L., & Daly, R. M. (2021). Minimal-Dose Resistance Training for Improving Muscle Mass, Strength, and Function: A Narrative Review of Current Evidence and Practical Considerations. Sports Medicine, 1-17.
Resistance training (RT) is the only non-pharmacological intervention known to consistently improve, and therefore offset age-related declines in, skeletal muscle mass, strength, and power. RT is also associated with various health benefits that are underappreciated compared with the perceived benefits of aerobic-based exercise. For example, RT participation is associated with reduced all-cause and cancer-related mortality and reduced incidence of cardiovascular disease, hypertension, and symptoms of both anxiety and depression. Despite these benefits, participation in RT remains low, likely due to numerous factors including time constraints, a high-perceived difficulty, and limited access to facilities and equipment. Identification of RT strategies that limit barriers to participation may increase engagement in RT and subsequently improve population health outcomes. Across the lifespan, declines in strength and power occur up to eight times faster than the loss of muscle mass, and are more strongly associated with functional impairments and risks of morbidity and mortality. Strategies to maximise healthspan should therefore arguably focus more on improving or maintaining muscle strength and power than on increasing muscle mass per se. Accumulating evidence suggests that minimal doses of RT, characterised by lower session volumes than in traditional RT guidelines, together with either (1) higher training intensities/loads performed at lower frequencies (i.e. low-volume, high-load RT) or (2) lower training intensities/loads performed at higher frequencies and with minimal-to-no equipment (i.e. resistance ‘exercise snacking’), can improve strength and functional ability in younger and older adults. Such minimal-dose approaches to RT have the potential to minimise various barriers to participation, and may have positive implications for the feasibility and scalability of RT. In addition, brief but frequent minimal-dose RT approaches (i.e. resistance ‘exercise snacking’) may provide additional benefits for interrupting sedentary behaviour patterns associated with increased cardiometabolic risk. Compared to traditional approaches, minimal-dose RT may also limit negative affective responses, such as increased discomfort and lowered enjoyment, both of which are associated with higher training volumes and may negatively influence exercise adherence. A number of practical factors, including the selection of exercises that target major muscle groups and challenge both balance and the stabilising musculature, may influence the effectiveness of minimal-dose RT on outcomes such as improved independence and quality-of-life in older adults. This narrative review aims to summarise the evidence for minimal-dose RT as a strategy for preserving muscle strength and functional ability across the lifespan, and to discuss practical models and considerations for the application of minimal-dose RT approaches.
https://doi.org/10.1007/s40279-021-01605-8
- Sammoud, S., Bouguezzi, R., Ramirez-Campillo, R., Negra, Y., Prieske, O., Moran, J., & Chaabene, H. (2021). Effects of plyometric jump training versus power training using free weights on measures of physical fitness in youth male soccer players. Journal of sports sciences, 1-8.
This study aimed to contrast the effects of power training (PT) and plyometric-jump-training (PJT) programmes on measures of physical fitness in prepubertal male soccer players. Thirty-three participants were randomly allocated to PT group (n = 11), PJT group (n = 11), and an active control group (CG; n = 11). Before and after 12 weeks of training, tests were performed for the assessment of sprint-speed , change-of-direction (CoD) speed, muscular strength , and aerobic-endurance (AE). Findings indicated significant group×time interaction effects for all sprint-speed intervals, CoD speed, AE, and strength (d = 0.20–0.32). Post-hoc analyses revealed significant, moderate-to-large improvements in all sprint-speed intervals, CoD speed, AE, and muscle strength following PT (ES = 0.71 to 1.38). The PJT induced significant, moderate-to-large enhancements in 10 m, 20 m, and 30 m sprint, CoD speed, and AE (ES = 0.51 to 0.96) with no significant changes for 5 m sprint-speed and muscle strength (ES = 0.71 and 0.16, respectively). No significant pre-post changes were observed for the CG . Overall, PT and PJT are effective means to improve various measures of physical fitness in prepubertal male soccer players. Notably, to additionally improve acceleration and muscle strength, PT has an advantage over PJT.
https://doi.org/10.1080/02640414.2021.1976570
- Delaney, J. A., McKay, B. A., Radcliffe, J., Benton, D. T., Samozino, P., Morin, J. B., & Duthie, G. M. (2021). Uphill sprinting load–and force–velocity profiling: Assessment and potential applications. Journal of sports sciences, 1-7.
This study aimed to quantify the validity and reliability of load–velocity (LV) relationship of hill sprinting using a range of different hill gradients and to describe the effect of hill gradient on sprint performance. Twenty-four collegiate-level athletes performed a series of maximal sprints on either flat terrain or hills of gradients 5.2, 8.8 and 17.6%. Velocity–time curves were recorded using a radar device. LV relationships were established using the maximal velocity achieved in each sprinting condition, whilst force–velocity–power (FVP) profiles were established using only the flat terrain sprint. LV profiles were shown to be valid (R2 = 0.99) and reliable (TE < 4.4%). For every 1-degree increase in slope, subjects’ velocity decreased by 1.7 ± 0.1% on average. All the slopes used represented low resistance relative to the entire LV spectrum (<25% velocity loss). Subjects who exhibited greater horizontal force output at higher velocities on flat terrain were most affected by the gradient of the hill. Hills of gradients up to 17.6% do not provide sufficient resistance to optimize power development. However, such hills could be used to develop late-stage technical ability, due to the prolonged horizontally oriented body position that occurs as subjects attempt to overcome the acceleration due to gravity.
https://doi.org/10.1080/02640414.2021.1992868
