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Jennifer Kappenstein, Jaime Fernández-Fernández, Florian Engel, and Alexander Ferrauti

The aim of this study was to compare the effect of active (AR) and passive recovery (PR) after a high-intensive repeated sprint running protocol on physiological parameters in children and adults. Blood lactate (La) and blood pH were obtained during two sets of 5 × 5 s all-out sprints and several times during subsequent 30-min recovery in 16 children and 16 adults. End-exercise La was significantly lower and pH significantly higher in children (La: 5.21 ± 2.73 mmol·L1; pH: 7.37 ± 0.06) compared with adults (La: 10.35 ± 5.76 mmol·L−1; pH: 7.27 ± 0.10) (p > .01). La half-life during postexercise recovery was significantly shorter in children (AR: 436 ± 371 s, PR: 830 ± 349 s) than in adults (AR: 733 ± 371 s, PR: 1361 ± 372 s), as well as in active compared with passive recovery for both age groups (p > .01). The age x recovery interaction for La half-life only approached statistical significance (p = .06). The results suggest a faster lactate disappearance and an earlier return to resting pH after a repeated sprint running protocol in children compared with adults and a less pronounced advantage of active recovery in children.

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Jaime Fernandez-Fernandez, David Sanz, Jose Manuel Sarabia, and Manuel Moya

Purpose:

To compare the effects of combining high-intensity training (HIT) and sport-specific drill training (MT) versus sportspecific drill training alone (DT) on fitness performance characteristics in young tennis players.

Methods:

Twenty young tennis players (14.8 ± 0.1 y) were assigned to either DT (n = 10) or MT (n = 10) for 8 wk. Tennis drills consisted of two 16- to 22-min on-court exercise sessions separated by 3 min of passive rest, while MT consisted of 1 sport-specific DT session and 1 HIT session, using 16–22 min of runs at intensities (90–95%) related to the velocity obtained in the 30–15 Intermittent Fitness Test (VIFT) separated by 3 min of passive rest. Pre- and posttests included peak oxygen uptake (VO2peak), VIFT, speed (20 m, with 5- and 10-m splits), 505 Agility Test, and countermovement jump (CMJ).

Results:

There were significant improvements after the training period in VO2peak (DT 2.4%, ES = moderate; MT 4.2%, ES = large) and VIFT (DT 2.2%, ES = small; MT 6.3%, ES = large) for both DT and MT, with no differences between training protocols. Results also showed a large increase in the 505 Agility Test after MT, while no changes were reported in the other tests (sprint and CMJ), either for MT or DT.

Conclusions:

Even though both training programs resulted in significant improvements in aerobic performance, a mixed program combining tennis drills and runs based on the VIFT led to greater gains and should be considered the preferred training method for improving aerobic power in young athletes.

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Jaime Fernandez-Fernandez, Alejandro Lopez-Valenciano, Jose Vicente Garcia-Tormo, David Cabello-Manrique, and Juan García-López

Purpose: To analyze the influence of playing 2 consecutive prolonged badminton matches on the shoulder strength and range of motion (ROM) of young players. Methods: Sixteen elite junior badminton players (12 males and 4 females; mean (SD): age 16.2 [0.8] years, body mass 63.5 [6.6] kg, height 173.2 [6.3] cm) participated in a cross-sectional study. Shoulder internal (IR)/external rotation (ER) ROM and IR/ER strength measures were conducted before and after 2 consecutive prolonged (ie, 35 min) matches and 12 hours after the second match. Results: After consecutive matches, IR strength of the dominant side and ER strength of the dominant and nondominant sides (effect size [ES] = 0.20–0.57) were reduced. Shoulder total ROM of the dominant side was decreased (ES = 0.80), while on the nondominant side, IR (ES = 0.66) was also decreased. After 12 hours, results showed decreased values in the IR/ER strength of the dominant side (ES = 0.36–1.00), as well as ER of both dominant and nondominant sides (ES = 0.30–0.59). IR ROM of the nondominant side (ES = 0.69) was also decreased. Conclusion: Present results showed that 2 consecutive matches on the same day with brief rest periods led to significant impairments in shoulder strength and ROM levels. These data can potentially elucidate the need for shoulder-specific training and recovery strategies prior to or during competitions.

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Cesar Gallo-Salazar, Juan Del Coso, David Sanz-Rivas, and Jaime Fernandez-Fernandez

Purpose: To determine whether the game activity and physiological responses of young tennis players differed depending on the session of play (eg, morning [MOR] vs afternoon [AFT]) and the final match outcome (eg, winners vs losers) during a simulated competition with 2 matches on the same day. Methods: A total of 12 well-trained male tennis players (age 14.5 [0.8] y) took part in a simulated competition of two 3-set matches separated by 3 h. All the matches were video recorded, and the participants were monitored using 10-Hz global positioning system units including a heart-rate monitor. Effect-size (ES) statistics were used to investigate the magnitudes of the differences. Results: During the AFT matches, in absolute terms, players covered longer total distance (ES = moderate) and ran more distance between 0 and ≤4 m·s−1 (ES = small to large) than in MOR matches. Total duration was also longer (ES = large) in the AFT, where the rest time between rallies was also longer (ES = very large). Heart rate was similar during AFT and MOR matches, but higher rates of perceived exertion (ES = moderate) were reported in the AFT. Only peak running velocity was observed to be likely higher for losers than for winners (ES = small). Conclusions: Game activity and physiological responses of young tennis players differ when 2 consecutive matches are played on the same day. These data might help elucidate the need for specific precompetition training loads and/or between-matches/sessions recovery strategies when facing overloaded competitions.

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Jaime Fernandez-Fernandez, Eduardo Sáez De Villarreal, David Sanz-Rivas, and Manuel Moya

Objectives:

The aim of this study was to analyze the effects of an 8-week (conducted biweekly for a total of 16 sessions) plyometric training program (PT) (e.g., upper- and lower-body exercises) combined with regular tennis training on physical qualities in young tennis players.

Design:

Sixty tennis players between the ages of 12 and 13 years (age 12.5 ± 0.3 years, weight 44.2 ± 7.0 kg, height 156.6 ± 7.1 cm) were allocated to either the control group (standard in-season regimen) (CG; n = 30) or the experimental group, which received an additional PT (TG; n = 30) for 30–60 min as a substitute for some tennis training within the usual 90-min practice.

Methods:

Pre- and posttests included: anthropometric measures; vertical countermovement jump (CMJ); standing long jump (SLJ); 20 m sprint time (with 5 and 10 m splits); a modified 505 agility test; overhead medicine ball throw; and serve velocity test.

Results:

After the training intervention, the TG showed significant (p < .01) improvements in all the parameters analyzed, with percentages of change and effect sizes ranging from 3.1% to 10.1% and 0.4 (small) to 1.3 (moderate), respectively. No significant changes were observed in the CG after the training intervention.

Conclusions:

PT was shown as an important stimulus for enhancing explosive actions in young tennis players.