Changes in Physical Performance Throughout Professional Soccer Match-Play.

ABSTRACT: Oliva-Lozano, JM, Granero-Gil, P, and Panascì, M. Changes in physical performance throughout professional soccer match-play. J Strength Cond Res 38(1): 123-127, 2024-The aim of this study was to explore the changes in physical performance by playing position throughout professional soccer match-play. Global Positioning Systems were used for the collection of external load measures during 35 matches. Each match was divided into 15-minute periods. Physical performance varied according to the period in distance covered ( F = 25.69; p < 0.001; partial eta-squared [ηp 2 ] = 0.11), sprinting distance (SPD, F = 4.35; p < 0.001; ηp 2 = 0.02), sprinting actions (SPAs, F = 5.19; p < 0.001), high-intensity accelerations (Acc+3, F = 2.18; p = 0.05; ηp 2 = 0.01), high-intensity decelerations (Dec+3, F = 4.51; p < 0.001; ηp 2 = 0.02), and high-metabolic load distance (HMLD, F = 5.59; p < 0.001; ηp 2 = 0.03). The period with the greatest mean physical performance was usually from the first half of the matches: 0-15 minutes (distance, Acc+3, and Dec+3) and 30-45 minutes (HMLD, SPA, and SPD). However, the lowest mean physical performance compared with the rest of 15-minute periods was observed in the 60-75-minute period (distance, HMLD, Acc+3, and Dec+3), except for SPA and SPD (15-30 minutes and 75-90 minutes). Overall, no significant differences ( p > 0.05) were observed in the physical performance between the extratime periods. In addition, the playing position had a significant effect on all performance variables ( F = 39.99-133.29; p < 0.001; ηp 2 = 0.14-0.34). Central defenders showed the lowest physical performance throughout the periods of match-play, whereas wide midfielders showed the greatest physical performance in all variables, except for distance covered, in which midfielders had the greatest performance. In conclusion, there were changes in physical performance during the matches depending on the period of match-play and playing position.

The Effect of Verbal Encouragement on Performance and Muscle Fatigue in Swimming.

Background and Objectives: Verbal encouragement (VE) can be used to enhance performance in several sports, even though no studies have been conducted among swimmers and only a few effects have been reported in elite athletes. Besides influencing motor performance, VE is also known to enhance the physical load, thus potentially increasing the probability of developing fatigue. With this in mind, this study aimed to explore the effects of VE in swimmers in order to fill in the knowledge gap concerning the aquatic environment. Materials and Methods: Each athlete swam a maximal 200 m freestyle trial under two different conditions: one trial with VE and the other without VE. The two main outcome measures were: (1) performance velocity (m/s); and (2) muscle fatigue, investigated by means of surface electromyography. Sixty swimmers were recruited, aged 18.63 ± 3.46 years (median 18 years), 28 men (47%), and 32 women (53%), with 7.03 ± 3.9 years of experience. Results: With VE, performance significantly improved in the swim trial (p < 0.001, effect size (ES) −0.95, large). When breaking the results down into the first half (first (0−100 m) vs. the second half (100−200 m)), the ES was large in the first part (−1.11), indicating an improvement in performance. This worsened, however, in the second part of the trial (ES 0.63). In the multivariate analysis, years of experience were found to be a significant predictor of the change in overall performance (p = 0.011). There was a significant increase in muscle fatigue induced by VE, overall, and during the second half, but not during the first half of the trial. Conclusions: The present study indicates that VE during a middle-distance event (200 m) increases performance most in swimmers with little experience. However, it has a negative impact on fatigue.

Effects of Two High-intensity Interval Training Concepts in Recreational Runners.

This study investigated the effects induced by 8 weeks of two high-intensity interval training (HIIT) protocols, 10-20-30 and 30-30 concepts, characterized by significantly different training volume and intensity, on physiological parameters, running performance, body composition and psychophysiological stress of recreational divided into two groups: the 10-20-30 group performed two 10-20-30 sessions/wk and one continuous training (CT)/wk, whilst the 30-30 group performed two 30-30 sessions/wk and one CT session/wk. VO2max, 1 km time, maximal aerobic speed (MAS), and body composition were evaluated before and after intervention. Internal load was measured through rating of perceived exertion (RPE). Both groups significantly improved running performance (1 km time: p=0.04; MAS: p=0.000001), aerobic fitness (VO2max: p=0.000002) and body composition (lean mass (kg) p=0.0001; fat mass (%) p=0.00005). RPE resulted significantly lower in the 10-20-30 group than in 30-30 group (10-20-30: 13.36±0.28; 30-30:15.55±0.21; p=0.0002). Thus, the 10-20-30 group improved physiological parameters, performance and body composition, similar to 30-30 with significantly lower RPE values. These results suggest that in recreational runners the 10-20-30 training is effective in improving aerobic fitness and performance, with a lower subjective perception of effort, thus enhancing individual compliance and adherence to the prescribed training program.

Warm-up plus verbal communications administered as placebo procedure during the training session improves running performance.

The aim of this study was to investigate the effects on running performance of a within-session placebo procedure consisting of a conditioning treatment plus verbal communications. Twenty-six subjects were assigned to PLACEBO and CONTROL groups. Participants performed three sessions: Session 1-Cooper Test, Session 2-Baseline session and Session 3-Experimental session. During Session 2, participants performed a sprint-interval-training (SIT)-until-exhaustion preceded by a general warm-up, while in Session3 the SIT was preceded by a conditioning treatment (FIFA11+ warm-up), known to be effective in preventing injuries but not improving performance. Moreover, in Session3, only the PLACEBO group received verbal suggestions (before the warm-up) to influence participants' expectations about FIFA11+ effectiveness in improving performance, and deceptive feedback (during each SIT recovery bout) to increase the conditioning effect. To evaluate performance improvements, Running Time was chosen as a main outcome while to ensure participants reached exhaustion, physiological and metabolic responses were monitored. Total running distance (TRD) was also measured. Results showed that, Running Time and TRD significantly increased in the PLACEBO group whilst no differences in the CONTROL group were observed thus, suggesting the effectiveness of the within-session-placebo procedure in improving running performance. These findings shed a new light on the interaction between cognitive domain and performance, thus encouraging coaches to adopt this innovative method during the training protocol to enhance athletes' performance. Moreover, this placebo procedure, not requiring additional time, tools or resources, could represent a more ecological approach that can be easily adopted in the field.

Short intermittent taekwondo test to assess athlete's physiological and metabolic profile.

BACKGROUND: The aim of this study was to assess the effectiveness of a new Short Intermittent Taekwondo Test (SITT) in 17 black belt athletes. METHODS: Maximal oxygen uptake (V̇O2max), carbon dioxide production (V̇CO2), respiratory exchange ratio (RER), heart rate (HR), and blood lactate concentration [La]+ during treadmill cardiopulmonary exercise test (CPET) and SITT were compared. SITT started with 10 sec of all-out kicks, alternating legs, and progressively increasing 5 s on each stage until the 4th stage. After the 4th stage the participants performed 25 s of turning kicks (Dolleo chagi), on each stage until the last (10th stage). The passive recovery phase after the 4th and the 7th stage lasted 30 s. RESULTS: V̇O2max and maximal HRmax were not significantly different (P=0.85 vs. P=0.76) between tests, while RER and [La]+ were significantly higher in SITT than in CPET (P=0.002 vs. P=0.001). No difference in RPE (P=0.84) was found. A significant positive correlation between two tests for V̇O2max and HRmax was found. CONCLUSIONS: Our findings showed that SITT induces physiological responses like CPET suggesting that it can be used to assess aerobic power in national taekwondo athletes, thus helping coaches to select correctly training intensities and monitor athletes' aerobic performance along the training phases.

Shuttle Running Within a Small-Sided Game: Effects on Internal and External Workloads, in Young Elite Soccer Players.

PURPOSE: To compare the effects of 2 small-sided games (SSGs), shuttle running within the bout (SSG-S) versus possession play only (SSG-P) on acute physiological and metabolic responses, perception of effort, and performance. METHODS: Ten young elite male soccer players (age 18.6 [1.9] y) performed two 5vs5 SSG formats (SSG-S and SSG-P) consisting of 4 × 4 minutes with 1 minute of passive recovery between bouts, 2 times each, once a week, and in a randomized order. Heart rate, blood lactate concentration, and rating of perceived exertion were assessed as indices of internal workload. Total and relative distances, distance at moderate and high speed, distances traveled in accelerations (≥2 m·s-2) and decelerations (≤-2 m·s-2; DDEC), and average metabolic power were chosen as indices of external workload and collected with a 10-Hz portable global positioning system device. RESULTS: Total distance, distances traveled in acceleration, distances traveled in deceleration, average metabolic power (always P < .01 and g > 1.62-large effect), and distance at moderate speed (P = .03 and g = 0.84-large effect) were significantly higher in SSG-S than in SSG-P. Moreover, the SSG-S showed higher blood lactate concentration (P = .0001, g = 12.58-large effect) and rating of perceived exertion (P = .03, g = 1.14-large effect) values than SSG-P. No significant differences in peak heart rate, relative distance, and distance at high speed were found. CONCLUSIONS: Our study showed, in young competitive male soccer players, the effectiveness of an SSG format that includes shuttle running within each bout in the development of more relevant internal and external workloads. These experimental data should encourage coaches to use this new SSG regimen within the traditional weekly training program.

Efficacy of Resisted Sled Sprint Training Compared With Unresisted Sprint Training on Acceleration and Sprint Performance in Rugby Players: An 8-Week Randomized Controlled Trial.

PURPOSE: To compare the effects between resisted sled sprint training (RSS) and unresisted sprint training (URS) on sprint and acceleration performance, vertical jump, and maximal strength during an 8-week period of preseason training. METHODS: Twenty-six recreational active rugby players were randomly divided into either RSS or URS training groups and then performed 8 weeks of training, 2 sessions/wk of sprint-specific training program. The RSS group performed sprints by towing a sled overloaded with 12.6% of body mass for 2 of the 3 sets of 3 × 20-m sprints, plus one set was carried out with unresisted modality. The URS groups performed 3 sets of 3 × 20-m unresisted sprints. The measures of 10- and 30-m sprint times, vertical jump, and 3-repetition-maximum (3-RM) squat tests were performed at baseline and after 8 weeks. RESULTS: Ten- and 30-m sprint times (P < .05 and ηp2>.44) improved significantly more in RSS than in URS. Both groups improved significantly in vertical jump and 3-RM squat tests; however, no significant differences (P > .1 and ηp2<.11) between groups were found. CONCLUSIONS: Our findings indicate that an 8-week program of RSS is more effective than URS for enhancing sprint time performance in male recreational active rugby players. In addition, these data suggest that a sled overload corresponding to 12.6% of body mass can induce positive effects on both acceleration and speed performance in recreational active rugby players.

High-Intensity Interval Training for Rowing: Acute Responses in National-Level Adolescent Males.

Background: This study investigated the acute effects of two high-intensity interval training (HIIT) programs on physiological responses and internal workload. Methods: Ten national-level adolescent male rowers (age: 15.7 ± 0.2 years; maximal oxygen uptake (VO2max): 60.11 ± 1.91 mL∙kg−1∙min−1) performed two HIIT testing sessions: short (S-HIIT) and long (L-HIIT). In S-HIIT, the rowers performed 25 reps of 30 s at 100% power at VO2max (Pmax) interspersed with 30 s at P@20% Pmax; whereas in L-HIIT, the rowers executed 4 × 4 min at P@90% Pmax interspersed with 3 min of active recovery (P@30% Pmax). Results: The acute physiological responses and internal workload were evaluated. The significance level was set at p < 0.05. Oxygen uptake (VO2) (p < 0.05), time spent per session at ~90% VO2max (p < 0.01), total VO2 consumed (p < 0.01), total distance (p < 0.001), the rating of perceived exertion, blood lactate concentration and heart rate (always p < 0.0001) were significantly higher in L-HIIT than in S-HIIT. However, peak power output was significantly lower in L-HIIT compared to S-HIIT (p < 0.0001). Conclusion: In adolescent rowers, both HIIT tests stimulated aerobic and anaerobic systems. The L-HIIT test was associated with acute cardiorespiratory and metabolic responses, as well as higher perceptions of effort than the S-HIIT test. In adolescent rowers, HIIT emerges as an asset and could be introduced into a traditional in-season, moderate-intensity and endurance-based rowing program once a week.

Effects of Bilateral Dorsolateral Prefrontal Cortex High-Definition Transcranial Direct-Current Stimulation on Physiological and Performance Responses at Severe-Intensity Exercise Domain in Elite Road Cyclists.

PURPOSE: To investigate the effects of bilateral dorsolateral prefrontal cortex high-definition transcranial direct-current stimulation (HD-tDCS) on physiological and performance responses during exercise at the upper limit of the severe-intensity exercise domain in elite-level road cyclists. METHODS: Eleven elite-level road cyclists (VO2peak: 71.8 [3.1] mL·kg-1·min-1) underwent the HD-tDCS or SHAM condition in a double-blind, counterbalanced, and randomized order. After 20 minutes of receiving either HD-tDCS on dorsolateral prefrontal cortex (F3 and F4) or SHAM stimulation, participants completed a 10-minute constant-load trial (CLT1) at 90% of the first ventilatory threshold and a 2-minute CLT (CLT2) at peak power output. Thereafter, they performed a simulated 2-km time trial (TT). Maximal oxygen uptake, respiratory exchange ratio, heart rate, and rating of perceived exertion were recorded during CLT1 and CLT2, whereas performance parameters were recorded during the TT. RESULTS: In 6 out of 11 cyclists, the total time to complete the TT was 3.0% faster in HD-tDCS compared to SHAM. Physiological and perceptual variables measured during CLT1 and CLT2 did not change between HD-tDCS and SHAM. CONCLUSIONS: HD-tDCS over the dorsolateral prefrontal cortex seemed to improve cycling TT performance within the upper limit of the severe-intensity exercise domain, suggesting that an upregulation of the prefrontal cortex could be critical even in this exercise intensity domain. However, the limited dimension and the high interindividual variability require further studies to test these putative ergogenic effects.

The Effect of Static and Dynamic Stretching during Warm-Up on Running Economy and Perception of Effort in Recreational Endurance Runners.

This randomized crossover counterbalanced study investigated, in recreational runners, the acute effects of pre-exercise stretching on physiological and metabolic responses, endurance performance, and perception of effort. Eight male endurance runners (age 36 ± 11 years) performed three running-until-exhaustion tests, preceded by three warm-ups, including the following different stretching protocols: static (SS), dynamic (DS), and no-stretching (NS). During the SS and DS sessions, the warm-up consisted of 10 min of running plus 5 min of SS or DS, respectively, while during the NS session, the warm-up consisted of 15 min of running. Physiological and metabolic responses, and endurance running performance parameters, were evaluated. The perception of effort was derived from the rating of perceived exertion (RPE). Running economy significantly improved after SS (p < 0.05) and DS (p < 0.01), and RPE values were significantly lower in SS (p < 0.05) and DS (p < 0.01), compared to NS. No differences in physiological and metabolic responses among the sessions were found. This study showed that including SS and DS within the warm-up ameliorated running economy and decreased the perception of effort during a running-until-exhaustion test, highlighting the benefits of stretching on endurance performance. These results should encourage recreational runners to insert stretching during warm-up, to optimize the running energy costs, reducing the perception of effort and making the training sessions more enjoyable.

Not Breathing During the Approach Phase Ameliorates Freestyle Turn Performance in Prepubertal Swimmers.

This study compared the effects of two breathing conditions during the freestyle turn approach phase in swimmers. Thirty-four prepubertal swimmers (mean ± SD: 10.59 ± 0.97 years) were divided into two groups: No Breath (NB), not breathing at the last stroke, and Breath Stroke (BS). Swimmers performed three turns with 5 min of rest between the repetitions. Kinematic parameters were recorded with two underwater and two surface cameras. Total turn time (NB: 9.31 ± 1.34 s; BS: 10.31 ± 1.80 s; p = 0.049), swim-in time (NB: 3.89 ± 0.63 s; BS 4.50 ± 0.79 s; p = 0.02) and rotation time (NB: 2.42 ± 0.29 s; BS: 3.03 ± 0.41 s; p = 0.0001) were significantly shorter and swim-in distance [NB: 0.70 (0.58,0.77) m; BS: 0.47 (0.34,0.55) m; p = 0.0001], glide distance (NB: 1.06 ± 0.21 m; BS: 0.70 ± 0.20 m; p = 0.0001) and surfacing distance [NB: 1.79 (1.19,2.24) m; BS: 1.18 (0.82,1.79) m; p = 0.043] were significantly longer in NB than in BS. Moreover, speed-in (NB: 1.04 ± 0.14 m/s; BS: 0.93 ± 0.14 m/s; p = 0.031) and push-off speed (NB: 2.52 ± 0.30 m/s; BS: 1.23 ± 0.20 m/s; p = 0.001) were significantly higher in NB than in BS. Swim-in time was positively and negatively correlated with rotation time and glide distance, respectively, whilst negative relationships between total turn time and swim-in distance, total turn time and surfacing distance and total turn time and speed-in were found. Our study showed that in prepubertal swimmers not breathing at the last stroke during the approach phase positively affected kinematic parameters of the turn, allowing to approach the wall faster, rotate the body quicker, increase push-off speed, reduce turn execution time, thus improving overall turn performance.

Acute and Chronic Catabolic Responses to CrossFit® and Resistance Training in Young Males.

Given the wide variety of conditioning program trainings employed, the present study compared the catabolic effects induced by CrossFit® and resistance training in moderately trained subjects. Twenty males joined either the CrossFit® group (n = 10; 30 min/day of "workout of the day") or the resistance training (RT) group (n = 10; 30 min/day of resistance exercises) thrice a week, for 8 weeks. Salivary levels of cortisol, interleukin 1-beta (IL-1ß), and uric acid were assessed via enzyme-linked immunosorbent assays before (PRE) and 30-min after (POST) SESSION 1 and SESSION 24. Variables' percentual changes were computed as (POST-PRE)/PRE*100 in each session (Δ%). CrossFit® acutely increased cortisol levels in both sessions, with a significant decrease in Δ%cortisol from SESSION 1 to 24. In the RT group, cortisol values decreased in both sessions, only acutely. A significant decrease in IL-1ß levels was registered acutely in both groups, in both sessions, whereas Δ%IL-1ß was not different between the two groups. While uric acid levels increased in both groups acutely, a chronic downregulation of Δ%uric acid, from SESSION 1 to 24, was appreciated for the RT group only. Overall, CrossFit® appeared to induce more intense effects than the RT program as to the investigated catabolic responses.

Physiological responses during intermittent running exercise differ between outdoor and treadmill running.

The aim of this study was to compare the physiological responses during 15 min of intermittent running consisting of 30 s of high-intensity running exercise at maximal aerobic velocity (MAV) interspersed with 30 s of passive recovery (30-30) performed outdoor versus on a motorized treadmill. Fifteen collegiate physically active males (age, 22 ± 1 years old; body mass, 66 ± 7 kg; stature, 176 ± 06 cm; weekly training volume, 5 ± 2 h·week-1), performed the Fitness Intermittent Test 45-15 to determine maximal oxygen uptake (V̇O2max) and MAV and then completed in random order 3 different training sessions consisting of a 30-s run/30-s rest on an outdoor athletic track (30-30 Track) at MAV; a 30-s run/30-s rest on a treadmill (30-30 Treadmill) at MAV; a 30-s run/30-s rest at MAV+15% (30-30 + 15% MAV Treadmill). Oxygen uptake (V̇O2), time above 90%V̇O2max (t90%V̇O2max), and rating of perceived exertion (RPE) were measured during each training session. We observed a statistical significant underestimation of V̇O2 (53.1 ± 5.4 mL·kg-1·min-1 vs 49.8 ± 6.7 mL·kg-1·min-1, -6.3%, P = 0.012), t90%V̇O2max (8.6% ± 11.5% vs 38.7% ± 32.5%, -77.8%, P = 0.008), RPE (11.4 ± 1.4 vs 16.5 ± 1.7, -31%, P < 0.0001) during the 30-30 Treadmill compared with the same training session performed on track. No statistical differences between 30-30 +15 % MAV Treadmill and 30-30 Track were observed. The present study demonstrates that a 15% increase in running velocity during a high-intensity intermittent treadmill training session is the optimal solution to reach the same physiological responses than an outdoor training session.