Objective: To examine the association between phase angle (PhA) and bioelectrical impedance vector analysis (BIVA) and components of physical performance in male youth soccer players. Design: Cross-sectional. Methods: Sixty-two players from two professional soccer academies were recruited. Electrical bioimpedance was used to obtain the PhA and BIVA. Body fat (BF) and lean soft tissue mass (LSTM) were measured by dual-energy X-ray absorptiometry. All players completed physical tests including the standing long jump (SLJ), Carminatti’s test (peak speed at the end of the test, PST-CAR), 10 m and 30 m straight-line sprints, and repeated-sprint ability (RSA) test (RSAbest and RSAmean times). Results: Adjusting for chronological age, BF, and LSTM, multiple regression analysis outputs showed that PhA remained inversely related to RSAmean (β = −0.362; p < 0.001), RSAbest (β = −0.239; p = 0.020), 10 m (β = −0.379; p = 0.012), and 30 m (β = −0.438; p < 0.001) sprint times, while the association with PST-CAR and SLJ performance were statistically non-significant. In addition, BIVA showed that differences in confidence ellipses were found between athletes in the reference population and the study sample (p < 0.05). The tolerance ellipses indicated that the athletes in the present study had more total body water (TCW) and lower proportions of intracellular water (ICW) to extracellular water (ECW). The reference population had more TCW and ICW/ECW. Conclusions: Our results suggest that young soccer players with higher PhA values, indicating better cell integrity and functionality, have better performance in typical anaerobic running activities, such as sprinting speed and RSA performance, adjusted to age and body composition characteristics.

This study aimed to compare the effects of 6-week resisted sprint (RST) versus conventional (unresisted) sprint training (CG) on sprint time, change of direction (COD) speed, repeated sprint ability (RSA) and jump performance (countermovement jump (CMJ) and standing long jump (SLJ)) in male young tennis players. Twenty players (age: 16.5 ± 0.3 years; body mass: 72.2 ± 5.5 kg; body height: 180.6 ± 4.6 cm) were randomly assigned to one of the two groups: RST (n = 10) and CG (n = 10). The training program was similar for both groups consisting of acceleration and deceleration exercises at short distances (3-4 m), and speed and agility drills. The RST group used weighted vests or elastic cords during the exercises. After 6 weeks of intervention, both training regimes resulted in small-to-moderate improvements in acceleration and sprint ability (5, 10, 20 m), SLJ and CMJ performances, COD pivoting on both, the non-dominant (moderate effect) and the dominant (small effect) foot, and the percentage of decrement (small effects) during a RSA test. Between-group comparisons showed that the SLJ (Δ = 2.0%) and 5 m sprint time (Δ = 1.1%) improved more in the RST group compared with the CG group. This study showed that 6 weeks of RST or unresisted training are time-efficient training regimes for physical improvements in young male tennis players.

The aim of this study was to examine the relationship between the peak velocity derived from the Carminatti Test (T-CAR) (PV) and physical match performance in young soccer players. Thirty-three youth soccer players were recruited from 2 non-professional clubs. Friendly matches and small-sided game were performed. Physical match demands were assessed using Global Positioning System (GPS) technology. On a separate occasion, the players were submitted to the T-CAR. Players were categorised into 3 groups based on their T-CAR performance: Low (PV ≤ P33), Intermediate (P33 > PV < P66) and High (PV ≥ P66). The PV (15.5 ± 0.7 km·h) was significantly related to high-intensity activities (HIA; r = 0.78, P < 0.001), high-intensity running (HIR; r = 0.66, P < 0.001), sprinting (r = 0.62, P < 0.001) and total distance (TD) covered (r = 0.47, P < 0.01) during friendly matches. The PV was strongly correlated with the amount of HIA (r = 0.81, P < 0.001), HIR (r = 0.85, P < 0.001) and TD covered (r = 0.81, P < 0.001) during small-sided game. No significant correlation was observed between the PV and distance of sprinting (r = 0.49, P = 0.067) during small-side game. Furthermore, players in the High group covered significantly more TD (10%) and did more HIA (42%), sprinting (31%) and HIR (25%) during friendly matches compared to the players classified as having Low performance on the T-CAR. These differences still remained after adjusting for chronological age (CA), maturity and body size. In conclusion, the current study gives empirical support to the ecological and construct validity of this novel field test (T-CAR) as an indicator of match-related physical performance in young soccer players during pubertal years.

Fernandez-Fernandez, J, García-Tormo, V, Santos-Rosa, FJ, Teixeira, AS, Nakamura, FY, Granacher, U, and Sanz-Rivas, D. The effect of a neuromuscular vs. dynamic warm-up on physical performance in young tennis players. J Strength Cond Res 34(10): 2776–2784, 2020—The aim of this study was to examine performance-enhancing (i.e., training) effects of a neuromuscular warm-up (NWU) compared with a dynamic WU (DWU) in young tennis players. Twenty-eight well-trained male tennis players with a mean age of 15.09 ± 1.16 years participated in this study and were assigned to either a training group performing NWU (n = 14), or a group that followed DWU (n = 15) before tennis-specific training, for 8 weeks. Pretest and posttest included: speed (5, 10, and 20 m); modified 5-0-5 change of direction (COD) test; bilateral/unilateral countermovement jump (CMJ); 2 kg overhead, forehand, and backhand-side medicine ball throw performance (MBT); serve velocity, and shoulder strength and range-of-motion (ROM) performance (i.e., internal [IR]/external [ER] rotation). Results showed that both groups, NWU and DWU, significantly improved their sprint performances (5–20 m; [p < 0.05; d = 0.83–1.32]), CMJ (bilateral and unilateral [dominant side] [p < 0.005; d = 1.27–1.59]), overhead MBT (p = 0.014; d = 1.02), and some shoulder strength (i.e., IR dominant side [D], ER D, ER/IR ratio [p < 0.05; d = 0.86–1.59]) and ROM (i.e., ER D, total ROM D [p < 0.05; d = 0.80–1.02]) values. However, the interaction effects revealed that NWU compared with DWU produced greater performance gains in most of the analyzed parameters (i.e., 5–10 m sprint, CMJ, overhead MBT, serve speed). The inclusion of an NWU characterized by a relatively low volume (∼20–35 minutes), including general mobility, core, and shoulder strength exercises, combined with neuromuscular-related exercises (e.g., plyometric and acceleration/deceleration/COD drills), can be recommended to obtain positive effects in tennis performance-related variables.

During the preseason, futsal players deal with large internal load, which may result in a reduction in physical performance. The aims of this study were to compare the session rating of perceived exertion training load (s-RPE TL) during the preseason between two teams; and to analyze the changes on the delayed-onset muscle soreness (DOMS), aerobic- and speed-power characteristics in players accumulating different s-RPE TL (Low (LTL) vs. High (HTL)). Twenty-eight players (Team A, n = 15; Team B, n = 13) were recruited. The s-RPE TL was monitored throughout the preseason phase (five weeks) in both teams. The coaches of each team planned the activities that comprised their training programs, without any interference from the researchers. Team A evaluated countermovement jumps (CMJ) and DOMS weekly. Team B performed squat jumps (SJ), CMJ, 5 m and 15 m sprints, and a futsal intermittent endurance test (PVFIET) before and after the preseason. Team B accumulated an almost-certainly greater s-RPE TL than Team A. In Team A, the CMJ height was likely to almost certainly improved for the HTL group from week 3. In Team B, the 5 m and 15 m sprint likely decreased after the preseason. Changes in 5 m (r = −0.61) and 15 m (r = −0.56) were correlated with total s-RPE TL. Changes in PVFIET were positively associated with changes in sprint, but inversely related to the baseline. s-RPE TL differed between both teams, and substantial gains in neuromuscular performance were observed for the HTL group in Team A. Slower and faster players in Team B showed distinct intermittent-endurance and speed adaptive responses during the high-volume preseason.