A New Training Load Quantification Method at Supramaximal Intensity and Its Application in Injuries Among Members of an International Volleyball Team.

ABSTRACT: Bouzigues, T, Maurelli, O, Imbach, F, Prioux, J, and Candau, R. A new training load quantification method at supramaximal intensity and its application in injuries among members of an international volleyball team. J Strength Cond Res XX(X): 000-000, 2024-The quantification of training loads (TLs) is essential for optimizing jump performance and reducing the occurrence of injuries. This study aimed to (a) propose a new method for quantifying TLs in explosive exercises, (b) determine the nature of the relationship between TLs dynamics and injury occurrence, and (c) assess a TL critical for training schedule purposes, above which the risk of injury occurrence becomes unacceptable. This study was conducted with 11 male volleyball players on a national team during a 5-month international competitive period. The proposed new method for quantifying TLs is based on a weighting factor applied to relative jumping intensities, determined by the number of sustainable jumps and their intensities measured by G-Vert accelerometer. The relationship between TLs dynamics and injury occurrence was assessed using a variable dose-response model. A high coefficient of determination was found between the maximum number of jumps possible and their intensities ( r2 = 0.94 ± 0.14, p < 0.001), indicating a strong physiological relationship between jumping intensities and the constraints imposed. The occurrence of injury was dependent on TLs dynamics for 2 players ( r2 = 0.26 ± 0.01; p < 0.001). The TL critical corresponded to 11 jumps over 80% of maximum jump height during games and approximately 130 jumps at <80% of maximal jump height. The present study proposes a new approach for quantifying supramaximal exercises and provides tools for training schedules and the prevention of volleyball injuries.

Effects of Tactical Periodization on Workload, Physical Fitness, and Well-Being in Professional Rugby Union Players During a Preseason Period.

ABSTRACT: Hu, X, Boisbluche, S, Philippe, K, Maurelli, O, Li, S, Xu, B, and Prioux, J. Effects of tactical periodization on workload, physical fitness, and well-being in professional rugby union players during a preseason period. J Strength Cond Res 38(1): 105-115, 2024-Tactical periodization (TP) emerged approximately 30 years ago and has recently gained considerable attention in rugby union (RU). It aims to develop specific physical fitness components with 3 acquisition days (strength, endurance, and speed). However, no study has investigated the effects of TP on workload, physical fitness, and well-being across an RU preseason. This study aimed to determine how RU players' workload response to TP focusing on positional differences, observe the influence of a TP preseason training program on aerobic fitness and neuromuscular performance between positions, and analyze the variation of well-being reported by forwards and backs from the 3 acquisition days. Thirty-two male players completed a 6-week TP protocol. External and internal workload variables were recorded through global positioning systems and session rating of perceived exertion (s-RPE) separately. Fitness assessments included Bronco and countermovement jump (CMJ) tests. The sum of well-being indices was measured using the Hooper index. Kruskal-Wallis H tests revealed that the highest values of PlayerLoad slow, PlayerLoad slow percentage, and s-RPE were found on endurance day and the lowest on speed day. Mann-Whitney U tests showed that 15 external workload parameters were higher in backs than forwards for each acquisition day. Small improvements were observed on the Bronco test. No differences were observed in CMJ performance during the preseason period and well-being values between acquisition days. This study provides unique insights into external and internal workload variables during each acquisition day. Furthermore, it highlights TP as an efficient theoretical concept to use in an RU context.

Inflammatory cytokines and metabolic responses to high-intensity intermittent training: effect of the exercise intensity.

To examine the effects of two high-intensity intermittent training (HIIT) programs of varying intensities (100% vs. 110% of maximal aerobic velocity [MAV]) on metabolic, hormonal and inflammatory markers in young men. Thirty-seven active male volunteers were randomly assigned into: HIIT experimental groups (100% MAV [EG100, n = 9] and 110% MAV [EG110, n = 9]) and a control groups (CG100, n = 9 and CG110, n = 9). Particpants performed high intesity intermittent exercise test (HIIE) at 100% or 110% MAV. Venous blood samples were obtained before, at the end of HIIE and at 15 min of recovery, and before and after 8 weeks of HIIT programs. After training, Glucose was lower (p < 0.01) in EG100 (d = 0.72) and EG110 (d = 1.20) at the end of HIIE, and at 15 min recovery only in EG110 (d = 0.95). After training, Insulin and Cortisol were lower than before training in EG100 and EG110 at the end of HIIE (p < 0.001). After HIIT, IL-6 deceased (p < 0.001) in EG100 (d = 1.43) and EG110 (d = 1.56) at rest, at the end of HIIE (d = 1.03; d = 1.75, respectively) and at 15 min of recovery (d = 0.88;d = 1.7, respectively). This decrease was more robust (p < 0.05) in EG110 compared to EG100. After HIIT, TNF-α deceased (p < 0.001) in EG100 (d = 1.43) and EG110 (d = 0.60) at rest, at the end of HIIE (0.71 < d < 0.98) and at 15 min of recovery (0.70 < d < 2.78). HIIT with 110% MAV is more effective in young males on the improvements of some metabolic (Glucose), hormonal (Cortisol) and inflammatory (IL-6) markers at rest, at the end of HIIE and 15 min of recovery than training at 100 % MAV.

The Relationships Between Skeletal Muscle Index and Bone Variables in a Group of Young Adults.

The purpose of this study was to investigate the relationships between skeletal muscle index (SMI) and bone variables in a group of young adults. Three hundred and thirty-five young adults (129 men and 206 women) whose ages ranged from 18 to 35 yr voluntarily participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. Body composition, bone mineral content (BMC), bone mineral density (BMD), geometric indices of hip bone strength and trabecular bone score (TBS) were determined for each individual by Dual-energy X-ray absorptiometry (DXA). Appendicular skeletal mass (ASM, in kg) was calculated by summing the muscle masses of the 4 limbs, assuming that all nonfat and nonebone mass is skeletal muscle. Skeletal muscle index (SMI) was defined as ASM/height². In young men, SMI was positively correlated to WB BMC (r = 0.63; p < 0.001), WB BMD (r = 0.53; p < 0.001), L1-L4 BMC (r = 0.33; p < 0.001), L1-L4 BMD (r = 0.30; p < 0.001), L1-L4 TBS (r = 0.26; p < 0.01), TH BMC (r = 0.61; p < 0.001), TH BMD (r = 0.46; p < 0.001), FN BMC (r = 0.51; p < 0.001), FN BMD (r = 0.46; p < 0.001), FN cross-sectional area (CSA) (r = 0.56; p < 0.001), FN cross-sectional moment of inertia (CSMI) (r = 0.52; p < 0.001) and FN section modulus (Z) (r = 0.54; p < 0.001) but negatively correlated to FN strength index (SI) (r = -0.24; p < 0.01). In young women, SMI was positively correlated to WB BMC (r = 0.61; p < 0.001), WB BMD (r = 0.60; p < 0.001), L1-L4 BMC (r = 0.35; p < 0.001), L1-L4 BMD (r = 0.33; p < 0.001), L1-L4 TBS (r = 0.29; p < 0.001), TH BMC (r = 0.61; p < 0.001), TH BMD (r = 0.53; p < 0.001), FN BMC (r = 0.45; p < 0.001), FN BMD (r = 0.49; p < 0.001), FN CSA (r = 0.60; p < 0.001), FN CSMI (r = 0.52; p < 0.001), and FN Z (r = 0.40; p < 0.001) but negatively correlated to FN SI (r = -0.20; p < 0.01). The current study suggests that SMI is a positive determinant of bone mineral density and geometric indices of hip bone strength in young adults.

Ventilatory responses at submaximal exercise intensities in healthy children and adolescents during the growth spurt period: a semi-longitudinal study.

PURPOSE: To identify the changes of ventilation ([Formula: see text]E), tidal volume (VT) and respiratory frequency (fr) at different incremental step test intensities during maturation of children and adolescents. METHODS: A semi-longitudinal study was conducted on 68 healthy untrained boys and girls aged 11-17 years. The subjects were separated into three distinct age groups. [Formula: see text]E, VT and fr parameters were evaluated annually during 3 years by modifying incremental step test intensities according to ventilatory threshold (VTh) level (30, 60 and 90% of [Formula: see text]O2max). Absolute and relative values of ventilatory responses were analyzed and compared according to age and developmental phase. RESULTS: (1) Height, weight, lean body mass and vital capacity increased significantly from 11 to 17 years of age. (2) [Formula: see text]O2max, [Formula: see text]E, and VT increased during maturation even when exercise intensity changed, especially from 11 to 15 years of age. On the other hand, fr showed a decreasing trend. CONCLUSION: Increases of VT are the main reason for [Formula: see text]E increases during maturation of children. fr decreased independently of total body mass during maturation. [Formula: see text]E.kg-1 was stable despite intensity variations. VT.kg-1 increased significantly from 11 to 15 years then stabilized at 17 years. Lean body mass seems to explain the evolution of VT.kg-1 during maturation.

Key performance indicators in Tour de France sailing.

This study aimed to determine the key performance indicators of inshore sailing during the sailing Tour de France. Technical and physical parameters were investigated to determine the discriminating factors between successful and less successful international level sailors. Measurements from 21 sailors (mean ± SD; age = 23.81 ± 4.18 years) were conducted prior to the sailing Tour de France. Global Positioning System data of all participating teams (n = 23) was analysed. Sailors were divided into two groups (i.e. successful and less successful) according to qualifying performance percentage. The differences between successful and less successful sailors were explored by means of independent t-tests. Results indicate that successful boats displayed higher maximal speed, higher average speed and more efficient starting performance per race than less successful boats. Successful sailors have stronger handgrip strength, higher isometric maximal voluntary force relative to bodyweight (isometric mid-thigh pull) and more powerful submaximal pulling (bench pull) actions than their less successful counterparts. The results of this study suggest that multiple sailing, physical and physiological variables are related to sailing performance in inshore sailing. Therefore, we emphasize the importance of integrating specific testing protocols to evaluate the performance potential of inshore sailors participating in the sailing Tour de France.

Energy Demands in Well-Trained Alpine Ski Racers During Different Duration of Slalom and Giant Slalom Runs.

Bottollier, V, Coulmy, N, Le Quellec, L, and Prioux, J. Energy demands in well-trained alpine ski racers during different duration of slalom and giant slalom runs. J Strength Cond Res 34(8): 2156-2164, 2020-The purpose of this study was to investigate the energy demands of different duration slalom (SL) and giant slalom (GS) events in well-trained alpine ski racers. Eight well-trained alpine ski racers (age: 18.2 ± 0.8 years; stature: 1.72 ± 0.10 m; body mass: 65.8 ± 12.0 kg) performed an incremental laboratory test on cycle ergometer and 4 standardized alpine ski runs: short (ST) and long (LG) versions of SL and GS (SLST, SLLG, GSST, and GSLG). Oxygen uptake (V[Combining Dot Above]O2) and heart rate (HR) were recorded continuously in all conditions. Blood lactate ([La]) was determined immediately before run and 3 and 5 minutes after run ([La]peak). The contribution of aerobic, glycolytic, and phosphagen energy systems was estimated. The aerobic system was the primary energy system involved in GSST (43.9 ± 5.7%) and GSLG (48.5 ± 2.5%). No significant difference in the contribution of aerobic and glycolytic systems was observed in SLST and SLLG. [La]peak was higher in SLLG (11.10 ± 2.41 mmol·L) than in GSST (8.01 ± 2.01 mmol·L). There was no difference in oxygen uptake peak between GSST and GSLG. Energetic training goals should focus on the improvement of both aerobic, glycolytic, and phosphagen systems for alpine ski racers who perform SL and GS. Giant slalom specialists might benefit from emphasizing the improvement of the aerobic system, without neglecting other systems.

Influence of Weekly Workload on Physical, Biochemical and Psychological Characteristics in Professional Rugby Union Players Over a Competitive Season.

Dubois, R, Lyons, M, Paillard, T, Maurelli, O, and Prioux, J. Influence of weekly workload on physical, biochemical and psychological characteristics in professional rugby union players over a competitive season. J Strength Cond Res 34(2): 527-545, 2020-This study aimed to (a) quantify the physical workload (P-WL) during training and games throughout the professional rugby season and (b) analyze the influence of the season period and weekly-WL, at short (acute) and moderate (chronic) terms, on physical, biochemical, and psychological responses during the season. Physiological (physical and biochemical) responses to P-WL were analyzed by examining changes in the individual Z score of the Yo-Yo intermittent recovery test (YYIRT), submaximal aerobic tests (5'/5'-test), strength tests, countermovement jump tests, blood sampling, and "recovery-stress" scores (RESTq) in 14 professional players (26.9 ± 1.9 years). Changes throughout the season were analyzed using a linear mixed model to identify changes in P-WL, whereas repeated-measures analysis of variance was used to analyze changes in physiological responses across the season. The relationship between P-WL and physiological responses was analyzed using Pearson's correlation coefficient (r). The results showed that the preseason period comprised the highest level of P-WL compared with all other blocks across the season (p < 0.001). The acute P-WL, acute competitive-WL, and number of impacts seemed to be the WL parameters, which most influenced the physiological responses (changes in testosterone [T], cortisol [C], T/C ratio, IGF-1/C ratio, strength, and RESTq index). The chronic P-WL, particularly conditioning-WL, induced positive changes in fitness characteristics (YYIRT and 5'/5'-test). Finally, this study provides information to players and coaches alike as to the influence of P-WL on as well as adaptations in physiological and psychological indices throughout a playing season. This information can greatly inform the training and preparation of future players in different levels.

Does Muscular Power Predict Bone Mineral Density in Young Adults?

The aim of this study was to explore the relationships between maximum power and bone variables in a group of young adults. Two hundred and one young adults (53 men and 148 women) whose ages range from 18 to 35 years voluntarily participated in this study. Weight and height were measured, and body mass index was calculated. Body composition, bone mineral content (BMC) and bone mineral density (BMD) were determined for each individual by dual-energy X-ray absorptiometry. Vertical jump was evaluated using a validated field test (Sargent test). The highest vertical jump was selected. Maximum power (P max, in watts) of the lower limbs was calculated accordingly. In young men, maximum power was positively correlated to whole body (WB) BMC (r = 0.65; p < 0.001), WB BMD (r = 0.41; p < 0.01), L1-L4 BMC (r = 0.54; p < 0.001), total hip (TH) BMC (r = 0.50; p < 0.001), femoral neck (FN) BMC (r = 0.35; p < 0.01), FN cross-sectional area (CSA) (r = 0.33; p < 0.05) and FN cross-sectional moment of inertia (CSMI) (r = 0.50; p < 0.001). In young women, maximum power was positively correlated to WB BMC (r = 0.48; p < 0.001), WB BMD (r = 0.28; p < 0.001), L1-L4 BMC (r = 0.34; p < 0.001), TH BMC (r = 0.43; p < 0.001), TH BMD (r = 0.21; p < 0.01), FN BMC (r = 0.42; p < 0.001), FN BMD (r = 0.31; p < 0.001), FN CSA (r = 0.41; p < 0.001), FN CSMI (r = 0.40; p < 0.001) and FN Z (r = 0.41; p < 0.01). The current study suggests that maximum power is a positive determinant of WB BMC, WB BMD, FN CSA, and FN CSMI in young men. It also shows that maximum power is a positive determinant of WB BMC, WB BMD, TH BMD, FN BMD, FN CSA, FN CSMI, and FN Z in young women.

Effects of Precompetitive Preparation Period on the Isokinetic Muscular Characteristics in World Class Handball Players.

Maurelli, O, Bernard, PL, Dubois, R, Ahmaidi, S, and Prioux, J. Effects of precompetitive preparation period on the isokinetic muscular characteristics in world class handball players. J Strength Cond Res 33(4): 1065-1074, 2019-The aim of this study was to describe the effects of 8 weeks of precompetitive preparation period (Pc2P) on the isokinetic muscular characteristics in world-class handball players. Nineteen male professional players (age, 26.6 ± 5.4 years) participated in the study. Two bilateral isokinetic tests of knee joint flexors (H; hamstring) and extensors (Q; quadriceps) were performed before and after Pc2P to determine the peak torque (PT), the mean power (MP), and the ratios (agonist-antagonist, dominant-nondominant, and combined). For the PT, Q at low angular velocity (60°·s) in concentric mode revealed no significant increase for the dominant or nondominant legs. For H, results showed a significant increase for both legs (p < 0.001). At the higher angular velocity (240°·s), Q was significantly increased for the dominant (p < 0.005) and nondominant (p < 0.002) legs and also H for both sides (p < 0.001). Eccentric mode (30°·s) showed a significant increase for dominant (p < 0.005) and nondominant (p < 0.01) legs. For MP, results showed significant increase at low angular velocity (p < 0.003) and high angular velocity (p < 0.01) for both legs. In eccentric mode, values showed a significant increase after Pc2P for dominant (p < 0.001) and nondominant (p < 0.02) legs. The ratios showed significant increase for the agonist-antagonist ratio at 60°·s for dominant leg (p < 0.003) and the nondominant leg (p < 0.01). At 240°·s, the values showed a significant difference for both side (p < 0.02). From an injury risk perspective, in addition to optimizing performance, these results demonstrated that 8 weeks of Pc2P increased the maximum strength and muscle power of international handball players, even if the ratios of the knee joint muscles did not change during this period.

Effects of the Competitive Season on the Isokinetic Muscle Parameters Changes in World-Class Handball Players.

Maurelli, O, Bernard, PL, Dubois, R, Ahmaidi, S, and Prioux, J. Effects of the competitive season on the isokinetic muscle parameters changes in world-class handball players. J Strength Cond Res 33(10): 2778-2787, 2019-The aim of this study is to investigate the effects of the competitive season on isokinetic muscular parameters of the lower limbs in world-class handball players. Nineteen, male, world-class, handball players (age, 26.6 ± 5.4 years) participated in the study. Two bilateral isokinetic tests of knee joint flexors (H; hamstring) and extensors (Q; quadriceps) were performed in the beginning and end of the competitive season to determine the peak torque (PT), the mean power, and agonist-antagonist ratio, dominant-nondominant ratio (DNDR), and combined ratio. The results showed a significant decrease in PT values at low angular velocity (60°·s) in concentric mode for Q on dominant leg (p < 0.001). The other PT values for dominant and nondominant legs at low and high angular velocities (240°·s) and in eccentric mode (30°·s) were not significantly different for Q and H. For mean power, values did not change at 60°·s. At 240°·s, we found a significant decrease in H for dominant leg (p < 0.001) but not for nondominant leg. In eccentric mode, the results showed a significant increase on both legs (p < 0.001). For the ratios, values significantly decreased for DNDR at 60°·s for Q (p < 0.03) and for agonist/antagonist ratio at 240°·s for the dominant leg (p < 0.01). The present results highlight the importance of integrating regular strength training sessions during the competitive season in world-class handball players. Accordingly, this study should help trainers to modify their planning to maximize strength and power qualities of the lower limbs of their players in addition to avoiding injuries.

Estimation of respiratory volume from thoracoabdominal breathing distances: comparison of two models of machine learning.

PURPOSE: The purposes of this study were to both improve the accuracy of respiratory volume (V) estimates using the respiratory magnetometer plethysmography (RMP) technique and facilitate the use of this technique. METHOD: We compared two models of machine learning (ML) for estimating [Formula: see text]: a linear model (multiple linear regression-MLR) and a nonlinear model (artificial neural network-ANN), and we used cross-validation to validate these models. Fourteen healthy adults, aged [Formula: see text] years participated in the present study. The protocol was conducted in a laboratory test room. The anteroposterior displacements of the rib cage and abdomen, and the axial displacements of the chest wall and spine were measured using two pairs of magnetometers. [Formula: see text] was estimated from these four signals, and the respiratory volume was simultaneously measured using a spirometer ([Formula: see text]) under lying, sitting and standing conditions as well as various exercise conditions (working on computer, treadmill walking at 4 and 6 km[Formula: see text], treadmill running at 9 and 12  km [Formula: see text] and ergometer cycling at 90 and 110 W). RESULTS: The results from the ANN model fitted the spirometer volume significantly better than those obtained through MLR. Considering all activities, the difference between [Formula: see text] and [Formula: see text] (bias) was higher for the MLR model ([Formula: see text] L) than for the ANN model ([Formula: see text] L). CONCLUSION: Our results demonstrate that this new processing approach for RMP seems to be a valid tool for estimating V with sufficient accuracy during lying, sitting and standing and under various exercise conditions.

Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods.

The aims of this study were (1) to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2) to explore the relationship between these methods and (3) to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y), over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax) were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; p<0.01) while the forwards cover more distance than the backs (+26.8 ± 5.7%; p<0.05) in moderate-speed zone (10-14.4 km·h-1). However, no significant difference in high-metabolic power distance was found between the backs and forwards. Indeed, the high-metabolic power distances were greater than high-speed running distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; p<0.001) between the two groups. Nevertheless, nearly perfect correlations were found between the total distance assessed using the traditional approach and the metabolic power approach (r = 0.98). Furthermore, there is a strong association (r = 0.93) between the high-speed running distance (assessed using the traditional approach) and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high-intensity thresholds demonstrates that the metabolic power approach may represent an interesting alternative to the traditional approaches used in evaluating the high-intensity running efforts required in rugby union games.

Differences in training load, jump performance and injury occurrence in elite youth volleyball players.

BACKGROUND: External and internal training load are used to monitor training effects in volleyball. Occurrence of injuries in volleyball is dependent of training loads and state of fitness but also playing positions and gender. This study aims to investigate the impact of gender and playing positions on injury occurrence among young volleyball players, considering both training loads and fitness levels. METHODS: Conducted from September 2021 to May 2022, this study involved 37 elite young volleyball players, comprising 16 female (176.8±3.6 cm; 65.3±5.7 kg; 13.9±1.1 years old) and 21 males (189.6±7.3 cm; 77.4±9.5 kg; 14.7±1.2 years old). G-Vert accelerometer was used to quantify training load. During these sessions, RPE, state of fitness and occurrence of injuries, were collected using a daily questionnaire. RESULTS: The primary findings indicate that males demonstrated a higher number of jumps, mean intensity, mean training load per session, and reported higher fitness levels compared to females (P<0.001). However, females were more injured than males (P<0.001). Setters were identified as the players with the highest jump frequency, albeit at lower heights and intensities than their counterparts (P<0.001). Among males, middle blockers exhibited the highest mean intensity and training load per session (P<0.01). CONCLUSIONS: The elevated frequency of injuries and a worse reported fitness levels among females, despite lower training loads, suggests a potential deficiency in physical preparation among young women, particularly in terms of their ability to perform repeated high-intensity jumps.

Optimization of training for professional rugby union players: investigating the impact of different small-sided games models on GPS-derived performance metrics.

Introduction: Professional rugby union players can improve their performance by engaging in small-sided games (SSGs), which simulate the movement patterns of the game. This study collected metrics related to running performance and mechanical workload and their relative values from both forward and back positions, aiming to explore the impact of different SSGs factors on athlete workload, as well as the workload difference between official games (OGs) and SSGs. Methods: The monitored GPS data were collected from SSGs with different player numbers and pitch sizes (five sessions), SSG rules (5 weeks, four sessions per week), and OGs conducted throughout the year. Additionally, the study compared changes in players' sprinting performance before and after two SSG sessions. Results: Backs had greater workload than forwards. Less space and number of players SSG (4 vs. 4, 660 m2) was conducive to facilitating training for players in acceleration and deceleration. Conversely, larger spaces were associated with improved running performance. However, the introduction of a floater had no significant impact on performance improvement. Additionally, the 7 vs. 4 model (seven players engaged with four opponents) resulted in the greatest workload during medium-hard accelerations (F = 52.76-88.23, p < 0.001, ηp 2 = 0.19-0.28). Japan touch model allowed for more high-speed running training (F = 47.93-243.55, p < 0.001, ηp 2 = 1.52). The workload performed by SSGs can almost cover that of OGs (F = 23.36-454.21, p < 0.05, ηp 2 = 0.03-0.57). In the context of ηp 2, values around 0.01, 0.06 and 0.14 indicate small, medium and large effects respectively. Discussion: However, given the significantly higher workload of SSGs and the slight decrease in sprinting performance, further research is required to examine the training patterns of SSGs. This study provided insight into the impact of player numbers, pitch size, and rules on rugby-specific SSGs. Coaches should optimize SSG setups for enhanced training outcomes, ensuring the long-term development of physical capacity, technical and tactical skills.

Position-specific workload of professional rugby union players during tactical periodization training.

The positional workload characteristics in rugby union on three acquisition days (i.e. strength, endurance, and speed days) of tactical periodization are still relatively unknown. Therefore, the primary aim of this study was to shed light on the positional external workload variables (10 Hz Global Positioning System and accelerometer microtechnology) and internal workload indicators (the session rating of perceived exertion) of players in a professional rugby union team by utilizing and comparing two tactical periodization models. Twenty-six male players (15 forwards and 11 backs) were recruited from a French second-division rugby club. Data were obtained over 10 weeks of in-season home games: a total of 780 observations were analyzed. Student's t-test observed different external workload profiles between positions among acquisition days. Mean external workload values, except PlayerLoadslow, were significantly higher (p≤0.01; effect size: 0.41-1.93) for backs than forwards for all acquisition days. Moreover, forwards perceived a higher internal workload than backs on the strength day of both models. The findings demonstrate that applying these two tactical periodization models could result in effective rugby union training. Validating external and internal workload characteristics on tactical periodization acquisition days enables extensive analysis of training load monitoring data; these data can be utilized to discover the unique characteristics of each position and design position-specific acquisition days to improve performance.

Effects of recovery mode (active vs. passive) on performance during a short high-intensity interval training program: a longitudinal study.

The aim of this longitudinal study was to compare two recovery modes (active vs. passive) during a seven-week high-intensity interval training program (SWHITP) aimed to improve maximal oxygen uptake ([Formula: see text]), maximal aerobic velocity (MAV), time to exhaustion (t lim) and time spent at a high percentage of [Formula: see text], i.e., above 90 % (t90 [Formula: see text]) and 95 % (t95 [Formula: see text]) of [Formula: see text]. Twenty-four adults were randomly assigned to a control group that did not train (CG, n = 6) and two training groups: intermittent exercise (30 s exercise/30 s recovery) with active (IEA, n = 9) or passive recovery (IEP, n = 9). Before and after seven weeks with (IEA and IEP) or without (CG) high-intensity interval training (HIT) program, all subjects performed a maximal graded test to determine their [Formula: see text] and MAV. Subsequently only the subjects of IEA and IEP groups carried out an intermittent exercise test consisting of repeating as long as possible 30 s intensive runs at 105 % of MAV alternating with 30 s active recovery at 50 % of MAV (IEA) or 30 s passive recovery (IEP). Within IEA and IEP, mean t lim and MAV significantly increased between the onset and the end of the SWHITP and no significant difference was found in t90 VO2max and t95 VO2max. Furthermore, before and after the SWHITP, passive recovery allowed a longer t lim for a similar time spent at a high percentage of VO2max. Finally, within IEA, but not in IEP, mean VO2max increased significantly between the onset and the end of the SWHITP both in absolute (p < 0.01) and relative values (p < 0.05). In conclusion, our results showed a significant increase in VO2max after a SWHITP with active recovery in spite of the fact that t lim was significantly longer (more than twice longer) with respect to passive recovery.

Energy Expenditure Estimation From Respiratory Magnetometer Plethysmography: A Comparison Study.

Physical activity (PA) quantification by estimating energy expenditure (EE) is essential to health. Reference methods for EE estimation often involve expensive and cumbersome systems to wear. To address these problems, light-weighted and cost-effective portable devices are developed. Respiratory magnetometer plethysmography (RMP) is among such devices, based on the measurements of thoraco-abdominal distances. The aim of this study was to conduct a comparative study on EE estimation with low to high PA intensity with portable devices including the RMP. Fifteen healthy subjects aged 23.84±4.36 years were equipped with an accelerometer, a heart rate (HR) monitor, a RMP device and a gas exchange system, while performing 9 sedentary and physical activities: sitting, standing, lying, walking at 4 and 6 km/h, running at 9 and 12 km/h, biking at 90 and 110 W. An artificial neural network (ANN) as well as a support vector regression algorithm were developed using features derived from each sensor separately and jointly. We compared also three validation approaches for the ANN model: leave one out subject, 10 fold cross-validation, and subject-specific. Results showed that 1. for portable devices the RMP provided better EE estimation compared to accelerometer and HR monitor alone; 2. combining the RMP and HR data further improved the EE estimation performances; and 3. the RMP device was also reliable in EE estimation for various PA intensities.

Effects of preseason training on body composition, running performance, biochemical markers and workload variation in professional rugby union players.

Few studies have examined the impact of a preseason training intervention through systematic measures in Pro D2 rugby union (RU). Therefore, this study aimed to describe the effects of 12 weeks of preseason training (three blocks) on body composition, running performance, biochemical markers, and workload (WL) variation in professional RU players. Physiological (physical and biochemical) responses to preseason WL were analyzed by examining changes in anthropometric characteristics, Yo-Yo intermittent recovery level 1 (Yo-Yo IR1) test, blood samples (BS), Hooper index (1-7), the 10-Hz global positioning system (GPS), and session rating of perceived exertion (s-RPE) in nineteen elite male players. Changes throughout the preseason were analyzed using the one-way and mixed-model analysis of variance. Significant (p < 0.01) improvements occurred in anthropometry and Yo-Yo IR1 running performance in forwards and backs. Total distance (p < 0.01) and impact (p < 0.05) during the second block were meaningfully higher than the other two blocks, with backs showing higher values than forwards. As expected, WL decreased significantly (p < 0.01) during the last training block. The WL variations were correlated with changes in biochemical markers over the preseason period. The collected data can be used for i) profiling French Pro D2 rugby championships players, ii) establishing effective training strategies, and iii) setting preseason WL expectations.

Energy expenditure estimate by heart-rate monitor and a portable electromagnetic coils system.

The aim of this article was to compare 2 portable devices (a heart-rate monitor and an electromagnetic-coil system) that evaluate 2 different physiological parameters--heart rate (HR) and ventilation (VE)--with the objective of estimating energy expenditure (EE). The authors set out to prove that VE is a more pertinent setting than HR to estimate EE during light to moderate activities (sitting and standing at rest and walking at 4, 5, and 6 km/hr). Eleven healthy men were recruited to take part in this study (27.6 ± 5.4 yr, 73.7 ± 9.7 kg). The authors determined the relationships between HR and EE and between VE and EE during light to moderate activities. They compared EE measured by indirect calorimetry (EEREF) with EE estimated by HR monitor (EEHR) and EE estimated by electromagnetic coils (EEMAG) in upright sitting and standing positions and during walking exercises. They compared EEREF with EEHR and EEMAG. The results showed no significant difference between the values of EEREF and EEMAG. However, they showed several significant differences between the values of EEREF and EEHR (for standing at rest and walking at 5 and 6 km/hr). These results showed that the electromagnetic-coil system seems to be more accurate than the HR monitor to estimate EE at rest and during exercise. Taking into consideration these results, it would be interesting to associate the parameters VE and HR to estimate EE. Furthermore, a new version of the electromagnetic-coil device was recently developed and provides the possibility to perform measurement under daily life conditions.