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Summary: The present study aimed to: (1) investigate sleep architecture in response to an overload training and taper periods among endurance runners; and (2) assess the sleep benefits of a high‐heat‐capacity mattress topper. Twenty‐one trained male endurance runners performed a 2‐week usual training regimen (baseline) followed by 2‐week overload and taper periods. From overload to the end of the taper period, they were assigned into two groups based on the mattress topper used: high‐heat‐capacity mattress topper (n = 11) or low‐heat‐capacity mattress topper (n = 10). Training load was assessed daily using the session rating of perceived exertion. Following each period, sleep was monitored by polysomnography, and nocturnal core body temperature was recorded throughout the night. Irrespective of the group, awakening episodes > 5 min decreased following overload compared with baseline (−0.48, p = 0.05). Independently of mattress topper, each 100 A.U. increase in 7‐day training load prior to polysomnographic recording was associated with higher slow‐wave sleep proportion (β = +0.13%; p = 0.05), lower sleep‐onset latency (β = −0.49 min; p = 0.05), and a reduction in the probability of transition from N1 sleep stage to wakefulness (β = −0.12%; p = 0.05). Sleeping on a high‐heat‐capacity mattress topper did not affect any sleep variable compared with a low‐heat‐capacity mattress topper. Increased training loads promote slow‐wave sleep and sleep propensity, highlighting the adaptative nature of sleep to diurnal activity and the role of sleep in physiological recovery. Further studies are required on the potential benefits of high‐heat‐capacity mattress toppers on sleep architecture among athletes. [ABSTRACT FROM AUTHOR]

Purpose: Muscle architecture is associated with motor performance and muscle injury. While muscle architecture and knee-flexor eccentric strength change with growth, the influence of anthropometric measures on these properties is rarely considered. This study aimed to investigate the relationship between hamstring muscle architecture and knee-flexor eccentric strength with anthropometric measurements. Methods: Sixty male footballers (16.6 [1.05] y) from the U16, U17, and U19 teams of an elite soccer club were included in this study. Fascicle length, pennation angle, and muscle thickness of the biceps femoris long head (BFlh) and semimembranosus muscles were measured in both legs using ultrasound. Knee-flexor eccentric strength, height, body mass, leg length, femur length, and peak height velocity (PHV) were measured within 1 week of the ultrasound images. A stepwise regression and 1-way analysis of variance tests were used to evaluate the effects of age, maturity, and anthropometric measurements on muscle properties. Results: Variance within BFlh and semimembranosus muscle thickness (r <.61), semimembranosus pennation angle (r <.58), and knee-flexor eccentric strength (r =.50) were highly related to body mass. We observed no significant correlations between muscle architecture and age (P >.29). However, moderately greater BFlh muscle thickness was shown for the post-PHV compared with the PHV group (effect size ± 90% CI: 0.72 ± 0.49). Conclusions: In conclusion, weak correlations between muscle architecture and anthropometric measurements suggest that other factors (ie, genetics, training regimen) influence muscle architecture. The moderate effect of maturity on BFlh muscle thickness strongly suggests post-PHV hypertrophy of the BFlh muscle. Our results confirmed previous findings that eccentric knee-flexor strength is influenced by body mass. [ABSTRACT FROM AUTHOR]

This study characterised the thigh muscle-tendon unit length variations (MTUv) in elite alpine skiing. MTUv were modelled for seven muscles from knee and hip angles in 17 national team skiers during 1602 cycles (546 Slalom (SL), 908 Giant-Slalom (GS), 136 Super-Giant (SG) and 12 Downhill (DH) cycles). The biarticular rectus femoris showed a dynamic pattern on both legs, especially in SL. On the other side, vastii displayed a stable length on the inside leg in all disciplines (37–46% of the cycle), contrasting with their dynamic behaviour on the outside leg being quasi-static for only 3% (SL) to 27% (DH) of the cycle. SL showed the largest amplitude of MTUv followed by GS, SG and DH. For vastus lateralis, MTUv was ~60%Lr.s−1 in SL but only ~12%Lr.s−1 in DH. In SL, a fine desynchronisation between both joints led to nearly constant MTUv (slow lengthening lasting ~45-51% of the cycle) for the biarticular hamstrings separated by faster variations during turn switch from outside to inside leg. In summary, biarticular MTUv were not characterised by single-joint behaviours, suggesting that extrapolating contraction regimen from knee joint only is not accurate in alpine skiing. [ABSTRACT FROM AUTHOR]

This study aimed to determine the relationship between the torque-generating capacity in sprint cycling and the strength capacity of the six lower-limb muscle groups in male and female world-class sprint cyclists. Eleven female and fifteen male top-elite cyclists performed 5-s sprints at maximal power in seated and standing positions. They also performed a set of maximal voluntary ankle, knee and hip flexions and extensions to assess single-joint isometric and isokinetic torques. Isokinetic torques presented stronger correlations with cycling torque than isometric torques for both body positions, regardless of the group. In the female group, knee extension and hip flexion torques accounted for 81.2% of the variance in cycling torque, while the ability to predict cycling torque was less evident in males (i.e., 59% of variance explained by the plantarflexion torque only). The standing condition showed higher correlations than seated and a better predictive model in males (R2 = 0.88). In addition to the knee extensors and flexors and hip extensors, main power producers, the strength capacity of lower-limb distal plantarflexor (and to a lesser extent dorsiflexor) muscles, as well as other non-measured qualities (e.g., the upper body), might be determinants to produce such extremely high cycling torque in males. [ABSTRACT FROM AUTHOR]

Perez, J, Guilhem, G, and Brocherie, F. Ice hockey forward skating force-velocity profiling using single unloaded vs. multiple loaded methods. J Strength Cond Res 36(11): 3229–3233, 2022—This study aimed to compare skating force-velocity relationships determined throughout sprints performed against various loaded conditions or inferred from movement kinetics measured during a single unloaded sprint. Ten female ice hockey players performed one unloaded maximal skating sprint test measured with a radar gun followed by 4 resisted skating sprints against a robotic horizontal resistance with progressive loads in reference to equipped body mass (BM): 3 kg (robotic resistance), 25, 50, and 75% of equipped BM. Maximal theoretical force (F0), velocity (V0), power (Pmax), optimal velocity (Vopt) condition for producing maximal power, and slope of the linear force-velocity relationship (SFV) were determined from each method and compared using a paired sample t -test, absolute mean bias (±95% confidence intervals), Pearson correlations, and typical error of the estimate in standardized units (effect size [ES]). Statistical significance was set at p < 0.05. No statistical difference was found for all mechanical variables determined from the 2 methods (p ranging 0.09–0.59). Although exhibiting positive correlations ranging from moderate (r = 0.50 for SFV) to high (r ranging from 0.71 to 0.84 for F0, V0, Vopt, and Pmax) between methods, all variables exhibited large levels of error between approaches (ES ranging 0.66–1.71). Multiple loaded and single unloaded methods were comparable with determine force-velocity relationships during forward on-ice skating sprint. The low-cost fatigue-free unloaded method suggests it could be used in constrained contexts (i.e., congested schedule and low available time) or for a simple force-velocity profiling. Inversely, multiple loaded methods would be more appropriate to evaluate and individualize training for skilled ice hockey players accustomed to resistive skating sprint. [ABSTRACT FROM AUTHOR]

Brocherie, F, Perez, J, and Guilhem, G. Effects of a 14-day high-intensity shock microcycle in high-level ice hockey players' fitness. J Strength Cond Res 36(8): 2247–2252, 2022—Elite athletes face congested schedules with increased competition frequency and restricted time for training periods. Therefore, time is lacking to design long-term sport-specific block periodization. This study aimed to investigate the effects of adding a 14-day off-ice high-intensity training (HIT) shock microcycle to the usual training content of the pre-season preparation of high-level male ice hockey players' fitness. Fourteen players were randomly assigned to off-ice HIT (n = 7) or usual pre-season training (control, n = 7). For the HIT group, additional off-ice training content included 2 sessions of repeated-maximal resistance training, 2 sessions of repeated-sprint training, and 2 sessions of high-intensity intermittent training. Control group performed equal number of off-ice sessions using traditional strength and conditioning training. Off-ice Yo-Yo intermittent recovery test level 2 (YYIR2) and on-ice repeated-sprint ability test (RSA) were conducted before (pre-test) and 3 days after the intervention (post-test). Statistical significance was set at p < 0.05. Significant group × time interactions were found for off-ice YYIR2 performance (p < 0.05) and on-ice RSA-cumulated skating time (RSATT; p < 0.05). Compared with pre-test, off-ice YYIR2 distance covered significantly increased (from 708.6 ± 97.2 to 885.7 ± 118.7 m, p < 0.01; +25.8 ± 16.9%, p < 0.05) and on-ice RSATT significantly decreased (from 28.35 ± 0.87 to 28.14 ± 0.84 seconds; −1.7 ± 2.1%, both p < 0.05)] for HIT group. No significant pre-test to post-test changes were found for the control group (+2.7 ± 20.0% for YYIR2 and +0.9 ± 2.2% for RSATT). The implementation of a 14-day shock microcycle (including 6 HIT sessions) significantly improved fitness performance in high-level male ice hockey players. Such HIT block periodization offers a promising way to deal with congested schedules. [ABSTRACT FROM AUTHOR]