A new approach to comparing the demands of small-sided games and soccer matches.

To improve soccer performance, coaches should be able to replicate the match's physical efforts during the training sessions. For this goal, small-sided games (SSGs) are widely used. The main purpose of the current study was to develop similarity and overload scores to quantify the degree of similarity and the extent to which the SSG was able to replicate match intensity. GPSs were employed to collect external load and were grouped in three vectors (kinematic, metabolic, and mechanical). Euclidean distance was used to calculate the distance between training and match vectors, which was subsequently converted into a similarity score. The average of the pairwise difference between vectors was used to develop the overload scores. Three similarity (Simkin, Simmet, Simmec) and three overload scores (OVERkin, OVERmet, OVERmec) were defined for kinematic, metabolic, and mechanical vectors. Simmet and OVERmet were excluded from further analysis, showing a very large correlation (r > 0.7, p < 0.01) with Simkin and OVERkin. The scores were subsequently analysed considering teams' level (First team vs. U19 team) and SSGs' characteristics in the various playing roles. The independent-sample t-test showed (p < 0.01) that the First team presented greater Simkin (d = 0.91), OVERkin (d = 0.47), and OVERmec (d = 0.35) scores. Moreover, a generalized linear mixed model (GLMM) was employed to evaluate differences according to SSG characteristics. The results suggest that a specific SSG format could lead to different similarity and overload scores according to the playing position. This process could simplify data interpretation and categorize SSGs based on their scores.

Soccer-drill specificity in top-class male players with reference to peak match locomotor demands.

To compare the locomotor demands of several ball/running drills with the official match peak, locomotor demands determined across different time-windows of the same duration in top-class male soccer players (n = 40). Total distance (TD), high-speed running (HSR, 15-20 km⋅h-1), very high-speed running (VHSR, 20-24 km⋅h-1), sprint and acceleration+deceleration (Acc+Dec >±3 m⋅s-2) distances were measured during training and official matches. A total of 9372 individual observations were classified as technical-tactical drills, small-sided games (SSGs), super-SSGs (pitch-area >340 m2·player), SSGs with rules modifications (SSGmodified), individual positional drills or running drills. The relative (m·min-1) TD, HSR, VHSR, sprint and Acc+Dec were compared with the peak locomotor demands determined during official matches across different time-windows (1, 2, 3, 4 and 5-min). Individual position-specific drill, super-SSGs, SSGmodified and running drills showed similar (P > 0.05) or higher (P < 0.05; ES:1.17/4.61) than match TD, HSR and VHSR, while sprint and Acc+Dec were lower (P < 0.05). Conversely, technical-tactical drills and SSGs showed lower (P < 0.05; ES:-1.00/-3.45) TD, HSR, VHSR, sprint and Acc+Dec than official match peak demands. Locomotor loads during technical-tactical drills and SSGs were lower than peak demands, particularly for VHSR and sprint. Since training intensity is a key factor for high-performance development, these results may help to prepare top-class players for the official match peak demands.

Small-Sided Games in Elite Football: Practical Solutions to Replicate the 4-min Match-Derived Maximal Intensities.

ABSTRACT: Riboli, A, Esposito, F, and Coratella, G. Small-sided games in elite football: practical solutions to replicate the 4-min match-derived maximal intensities. J Strength Cond Res 37(2): 366-374, 2023-The purpose of the study was to determine the area per player (ApP, m 2 ·player -1 ) to replicate the maximal 4-min match-play period (4-min Peak ) using small-sided or large-sided games (SSGs) lasting the same duration in elite football players. Twenty players (age: 26 ± 5 years) competing in European championship and international UEFA competitions were monitored during SSGs with (SSG with ) or without (SSG without ) goalkeepers, both lasting 4-min. A total of 1,724 and 561 individual observations for SSG with and SSG without across 99 and 34 different SSGs formats were undertaken. Whole (90-min avg ) and 4-min Peak match demands were calculated. Relative (m·min -1 ) total, high-speed (HSRD), very high-speed (VHSRD), sprint, and acceleration/deceleration distance were collected. For both SSG with and SSG without , ApP was small -to- very-largely correlated with TD, HSRD, VHSRD, and sprint, whereas an inverse trivial -to- small correlation with acceleration/deceleration was found. In SSG with , the ApP to replicate 4-min Peak was larger ( p < 0.001, effect size [ES]: 0.33-5.80) than that to mimic 90-min avg for total distance, HSRD, VHSRD, and sprint, whereas for acceleration/deceleration the ApP was lower ( p < 0.001, ES: -3.13 to 0.48) for 4-min Peak . In SSG without , the ApP to replicate 4-min Peak was larger ( p < 0.001, ES: 0.04-3.72) than that to mimic 90-min avg for HSRD, VHSRD, and sprint. Some positional differences ( p < 0.05, ES: 0.22-1.10) in ApP were found. The ApP to replicate 4-min Peak was higher for SSG with than SSG without ( p < 0.001, ES: 0.67-3.58). These findings may help practitioners to recreate the 4-min Peak to manage ApP during SSGs in elite football.

Technical and locomotor demands in elite soccer: manipulating area per player during small-sided games to replicate official match demands.

The present study aimed to investigate the area per player (ApP) to replicate the technical and locomotor match demands using small-sided games (SSGs) in male soccer players (n = 20) competing in major European and UEFA competitions. The relative number of each individual technical activity per minute (number · min-1; technical demands) was counted and the relative (m · min-1) total (TD), high-speed running (HSRD), very high-speed running (VHSRD), sprint and acceleration+deceleration (Acc+Dec) distances were collected during different SSG formats (n = 24; 4 vs 4 to 10 vs 10 with an ApP from 60 to 341 m2 · player-1) and official matches (n = 28). Data were collected during two full seasons. A linear mixed model analysis was used to calculate the individual relationship between technical/locomotor demands and the ApP during SSGs; the correlation coefficient was also calculated. With the exception of an inverse moderate (r = -0.457) correlation for Acc+Dec, each locomotor metric (TD, HSRD, VHSRD and sprint) showed a positive large to very large (r = 0.560 to 0.710) correlation with ApP (P < 0.001). The technical demands showed an inverse moderate correlation (r = -0.529) with ApP. Additionally, inverse moderate to large correlations (r = -0.397 to -0.600; P < 0.05) between the technical demands and the locomotor demands (TD, HSR, VHSR and sprint) were found. Lastly, an ApP of ~243 m2 · player was found to replicate the official match technical demand and it was quite similar to the ApP required to replicate HSRD, VHSRD and sprint. These findings may help practitioners to replicate, overload and underload both technical and locomotor demands using a specific ApP during SSGs in elite soccer.

Monitoring physical match performance relative to peak locomotor demands: implications for training professional soccer players.

This study aimed to analyse physical performance relative to peak locomotor demands of match play. Data were collected during 13 professional soccer matches. Initially, the 1-minute peak values were registered in each match, including the percentage of the total distance (TD), high-speed running distance (HSRD), sprinting distance (SPD), and high-metabolic load distance (HMLD), and a total of high-intensity accelerations and decelerations (Acc+Dec). Secondly, the time (measured in minutes) spent at different percentage ranges for the 1-minute peak values registered in each match was calculated. Thirdly, the physical performance required in the different percentage ranges for the 1-minute peak values were obtained. Finally, the time and physical performance required above the 90-minute average demands were calculated. The 90-minute average for all playing positions represented ~53% of the total distance (TD), ~23.4% of high-metabolic load distance (HMLD), ~16% of high-speed running distance (HSRD), ~11% of the total of high-intensity accelerations and decelerations (Acc+Dec), and ~6% of sprinting distance (SPD) for the 1-minute peak values. Likewise, statistically significant differences (p < 0.05) in the physical performance and time spent between specific percentage ranges for the 1-minute peak locomotor demands were also noted. In addition, all the variables reported that the physical performance required for above 90-minute average demands were significantly greater (p < 0.05) than the 90-minute average demands. Therefore, these findings may guide the prescription of training intensity by considering the physical performance relative to the peak locomotor demands of match play.

Training elite youth soccer players: area per player in small-sided games to replicate the match demands.

The aim was to determine the area per player (ApP, m2 × player) in small- or large-sided games to replicate the official match demands in elite youth soccer players. Two hundred and twenty-eight players (U15 = 36, U16 = 48, U17 = 49, U18 = 37 and U19 = 58) were monitored during both training (12 183 individual samples) and matches (683 individual samples) across five seasons. Relative (m × min-1) total (TD), high-speed running (HSR), very high-speed running (VHSR), sprint and acceleration/deceleration (Acc/Dec) distance were collected. Between-category and between-position comparisons were performed. Area per player was moderately correlated (P < 0.05) with TD (r = 0.401), large (r = 0.621) with HSR, and very largely with VHSR (r = 0.744) and sprint (r = 0.723). An inverse small (r = -0.232; P = 0.039) correlation for Acc/Dec was found. The area per player to replicate the match demands was 158 ± 18, 182 ± 32, 197 ± 37, 212 ± 42 and 156 ± 25 m2 × player for TD, HSR, VHSR, sprint and Acc/Dec, respectively. Moderate to very large (ES: 0.79 to 4.66) differences in the area per player across metrics were observed, with sprint > VHSR > HSR > TD = Acc/Dec. Trivial to very large (ES: 0.01 to 2.67) between-category differences in area per player across the same metric were found, with U15 and U16 requiring a larger area per player than other age categories. These findings may help practitioners to recreate the desired external load outcomes with regards to positional match-play demands using specific area per player in small- or large-sided games in youth elite soccer players from U15 to U19.

The distribution of match activities relative to the maximal intensities in elite soccer players: implications for practice.

To determine the distribution of match-activities relative to maximum-intensities during official match in elite soccer players. One hundred and forty-eight Italian Serie A soccer players were monitored during 46 official matches (680 individual-samples). Total distance (TD), high-speed running (HSR), very high-speed running (VHSR), sprint, acceleration and deceleration were calculated. Maximum-intensities (1-minpeak) were used as the reference value to determine the distribution of relative intensity across the whole-match demands (90-minavg). Time and distance higher than 90-minavg (>90-minavg) were also calculated. The relative (m·min-1) 90-minavg vs1-minpeak was 59.6(4.4)% for TD, 26.2(4.4)% for HSR, 16.0(3.5)% for VHSR, 9.3(2.3)% for sprint, 19.2(4.6)% for acceleration and 15.4(5.2)% for deceleration. Total distance covered >90-minavg was ~61.4(5.0)% for TD, ~68.6(1.9)% for HSR, ~80.2(1.3)% for VHSR, ~95.7(0.4)% for sprint, ~75.5(1.3)% for acceleration and ~64.0(2.6)% for deceleration. With the exception of small [ES: 0.50 (0.26 to 0.73)] difference for acceleration, the relative distance >90-minavg was largely to very largely (ES: 1.64 to 7.78) higher (P< 0.05) than the 90-minavg for each metric. While no between-position difference (P> 0.05) was found for total minutes >90-minavg, between-position differences (P< 0.05) for the total distance >90-minavg were retrieved across each metric. The distribution of the activities relative to maximal intensities could assist coaches for soccer training prescriptions.

Testing protocol affects the velocity at VO2max in semi-professional soccer players.

To compare three different protocols to assess the velocity associated with the maximal oxygen uptake (Vmax) in soccer players. Sixteen semi-professional soccer players performed three maximum incremental tests on treadmill: two continuous protocols [1 km·h-1·min-1 (CP1); and 1 km·h-1 every 2 min (CP2)], and one discontinuous (DP) protocol to determine Vmax, maximum oxygen uptake (VO2max) and oxygen cost of running (i.e., the slope of the VO2 vs velocity relationship at submaximal exercise). Vmax was higher in CP1> CP2> DP (19.4 ± 1.7, 17.4 ± 1.2, 16.1 ± 1.1 km·h-1 for CP1, CP2, and DP, respectively; P < 0.05 ES: 0.09 to 3.36). No difference in VO2max was found between CP1, CP2 and DP (P > 0.05). Oxygen cost of running showed between-protocol differences (CP1> CP2> DP; P < 0.05; ES: 0.28 to 3.30). Vmax was higher when determined using continuous vs discontinuous protocols due to the greater overestimation in oxygen cost of running. Such differences in Vmax should be considered to optimize acute physiological responses during high-intensity running activities.

Training status affects between-protocols differences in the assessment of maximal aerobic velocity.

PURPOSE: Continuous incremental protocols (CP) may misestimate the maximum aerobic velocity (Vmax) due to increases in running speed faster than cardiorespiratory/metabolic adjustments. A higher aerobic capacity may mitigate this issue due to faster pulmonary oxygen uptake ([Formula: see text]O2) kinetics. Therefore, this study aimed to compare three different protocols to assess Vmax in athletes with higher or lower training status. METHODS: Sixteen well-trained runners were classified according to higher (HI) or lower (LO) [Formula: see text]O2max [Formula: see text]O2-kinetics was calculated across four 5-min running bouts at 10 km·h-1. Two CPs [1 km·h-1 per min (CP1) and 1 km·h-1 every 2-min (CP2)] were performed to determine Vmax [Formula: see text]O2max, lactate-threshold and submaximal [Formula: see text]O2/velocity relationship. Results were compared to the discontinuous incremental protocol (DP). RESULTS: Vmax, [Formula: see text]O2max, [Formula: see text]CO2 and VE were higher [(P < 0.05,(ES:0.22/2.59)] in HI than in LO. [Formula: see text]O2-kinetics was faster [P < 0.05,(ES:-2.74/ - 1.76)] in HI than in LO. [Formula: see text]O2/velocity slope was lower in HI than in LO [(P < 0.05,(ES:-1.63/ - 0.18)]. Vmax and [Formula: see text]O2/velocity slope were CP1 > CP2 = DP for HI and CP1 > CP2 > DP for LO. A lower [P < 0.05,(ES:0.53/0.75)] Vmax-difference for both CP1 and CP2 vs DP was found in HI than in LO. Vmax-differences in CP1 vs DP showed a large inverse correlation with Vmax, [Formula: see text]O2max and lactate-threshold and a very large correlation with [Formula: see text]O2-kinetics. CONCLUSIONS: Higher aerobic training status witnessed by faster [Formula: see text]O2 kinetics led to lower between-protocol Vmax differences, particularly between CP2 vs DP. Faster kinetics may minimize the mismatch issues between metabolic and mechanical power that may occur in CP. This should be considered for exercise prescription at different percentages of Vmax.

Effect of formation, ball in play and ball possession on peak demands in elite soccer.

This study examined the most demanding passages of match play (MDP) and the effects of playing formation, ball-in-play (BiP) time and ball possession on the 1-min peak (1-minpeak) demand in elite soccer. During 18 official matches, 305 individual samples from 223 Italian Serie A soccer players were collected. MDP and 1-minpeak were calculated across playing position (central defenders, wide defenders, central midfielders, wide midfielders, wide forwards and forwards). Maximum relative (m·min-1) total distance (TD), high-speed running (HSR), very high-speed running (VHSR), sprint (SPR), acceleration/deceleration (Acc/Dec), estimated metabolic power (Pmet) and high-metabolic load (HML) distance were calculated across different durations (1-5, 10, 90 min) using a rolling method. Additionally, 1-minpeak demand was compared across playing formation (3-4-1-2, 3-4-2-1, 3-5-2, 4-3-3, 4-4-2), BiP and ball/no-ball possession cycles. MDP showed large to verylarge [effect-size (ES): 1.20/4.06] differences between 1-minpeak vs all durations for each parameter. In 1-minpeak, central midfielders and wide midfielders achieved greater TD and HSR (ES:0.43/1.13) while wide midfielders and wide forwards showed greater SPR and Acc/Dec (ES:0.30/1.15) than other positions. For VHSR, SPR and Acc/Dec 1-minpeak showed fourfold higher locomotor requirements than 90-min. 1-minpeak for Acc/Dec was highest in 4-3-3 for forwards, central and wide midfielders. 1-minPeak was lower during peak BiP (BiPpeak) for HSR, VHSR and Acc/Dec (ES: -2.57/-1.42). Comparing with vs without ball possession, BiPpeak was greater (ES: 0.06/1.48) in forwards and wide forwards and lower (ES: -2.12/-0.07) in central defenders and wide defenders. Positional differences in MDP, 1-minpeak and BiPpeak were observed. Soccer-specific drills should account for positional differences when conditioning players for the peak demands. This may help practitioners to bridge the training/match gap.

Effect of ramp slope on different methods to determine lactate threshold in semi-professional soccer players.

The present study aimed to investigate the effect of stage duration in incremental protocols on lactate threshold (LT), determined by different methods. Sixteen semi-professional soccer-players performed a 4-min stage incremental discontinuous (DP) and two maximal incremental running continuous (1 km h-1· min-1, CP1; and 1 km h-1·2 min-1 CP2) protocols. Blood-lactate concentration [La-] was measured at baseline and during the protocols. LT was determined using DMAX, DMAX-MOD, 4-mM⋅L-1, Δ1-mM⋅L-1 and Log-Log methods. Log-Log showed no difference in LT between CP1, CP2 and DP. Conversely, LT was determined at higher velocity in CP1 than CP2 for DMAX (15.2 ± 0.5 vs 14.4 ± 1.2 km⋅h-1, P = 0.002), DMAX-MOD (16.0 ± 0.5 vs 14.7 ± 1.3 km⋅h-1, P < 0.001), 4-mM⋅L-1 (15.5 ± 1.4 vs 14.4 ± 1.2 km⋅h-1, P < 0.001), Δ1-mM⋅L-1 (15.5 ± 1.3 vs 14.4 ± 1.2 km⋅h-1, P < 0.001). Higher LT in CP1 than DP for DMAX (15.2 ± 0.5 vs 13.0 ± 1.0 km⋅h-1, P < 0.001) and DMAX-MOD (16.0 ± 0.5 vs 13.6 ± 1.6 km⋅h-1, P < 0.001) was found (P < 0.001). Log-Log resulted in shorter but accurate protocols to determine LT.

Influence of acute passive stretching on the oxygen uptake vs work rate slope during an incremental cycle test.

PURPOSE: The aim of the study was to investigate the effects of acute passive stretching on O2 uptake (VO2) vs work rate slope during a continuous incremental ramp exercise. METHODS: On two different occasions, eight participants (age 23 ± 3 years; stature 1.71 ± 0.10 m; body mass 68 ± 8 kg; mean ± SD) performed two maximum incremental ramp tests on a cycle ergometer (25 W/min), with and without pre-exercise stretching. During tests, we measured VO2 and other metabolic and cardiorespiratory parameters on a breath-by-breath basis. The VO2 vs work rate slopes were calculated below (S 1) and above (S 2) the first ventilatory threshold (VET1). RESULTS: With stretching: (1) peak VO2 did not change, while peak work rate decreased (P < 0.05, ES = -0.41; CI -1.40/-0.58); (2) in spite of a similar S 1, S 2 was steeper by about 11 % (P < 0.05; ES = 0.62; CI -0.38/-1.62). CONCLUSIONS: Stretching reduced peak work rate and altered the [Formula: see text] vs work rate relationship above VET1 (S 2), without affecting peak VO2. The present findings have practical implications, questioning the use of stretching manoeuvres especially when peak work rate plays a key role in exercise performance.

Can small-sided games assess the training-induced aerobic adaptations in elite football players?

BACKGROUND: The aim of this study was to investigate whether or not SSGs could be used to evaluate the aerobic fitness status and the longitudinal training-induced adaptations in football players. Additionally, the capacity of SSGs to recreate the official match demands was investigated. METHODS: Twenty-five elite football players were monitored. Total distance (TD), high-speed running, very high-speed running, sprint and accelerations plus decelerations distance were measured during 20 SSGs formats and 25 official-matches; in SSGs, average heart rate was also collected. During submaximal Yo-Yo test, heart rate at peak exercise, heart rate post-60s recovery and rate of perceived exertion were collected. Coefficient of variation, interclass correlation-coefficient and correlation-coefficient analysis were used to calculate validity, reliability, construct validity and, internal and external responsiveness of SSGs demands. RESULTS: In SSGs, a small variability (~6.0%) with moderate reliability (~0.542 to ~0.663) was found in TD and heart rate, while a high variability (~20.8% to ~60.3%) with poor to moderate reliability (~0.358 to ~0.605) was observed in the other metrics; in submaximal Yo-Yo, heart rate showed small variability (~3.7%) with good reliability (~0.933 to ~0.916). The SSGs demands showed poor internal and external responsiveness (P>0.05) to the training-induced aerobic adaptations as assessed by submaximal Yo-Yo. The construct validity of SSGs showed overall large to very large correlations (r=0.53 to 0.90, P<0.05) between SSGs and official match demands across the season. CONCLUSIONS: SSGs should not replace standardized field tests to detect the training-induced aerobic adaptations. However, SSGs could be confidently used to recreate specific contextual factors in elite football players.

The Maximal Intensity Period: Rationalising its Use in Team Sports Practice.

Quantifying the highest intensity of competition (the maximal intensity period [MIP]) for varying durations in team sports has been used to identify training targets to inform the preparation of players. However, its usefulness has recently been questioned since it may still underestimate the training intensity required to produce specific physiological adaptations. Within this conceptual review, we aimed to: (i) describe the methods used to determine the MIP; (ii) compare the data obtained using MIP or whole-match analysis, considering the influence of different contextual factors; (iii) rationalise the use of the MIP in team sports practice and (iv) provide limitations and future directions in the area. Different methods are used to determine the MIP, with MIP values far greater than those derived from averaging across the whole match, although they could be affected by contextual factors that should be considered in practice. Additionally, while the MIP might be utilised during sport-specific drills, it is inappropriate to inform the intensity of interval-based, repeated sprint and linear speed training modes. Lastly, MIP does not consider any variable of internal load, a major limitation when informing training practice. In conclusion, practitioners should be aware of the potential use or misuse of the MIP.

Area per player in small-sided games to replicate the external load and estimated physiological match demands in elite soccer players.

The current study determined the area-per-player during small- or large-sided games with or without goalkeeper that replicates the relative (m·min-1) total distance, high-intensity running distance, sprint distance and metabolic power covered during official matches. Time-motion analysis was performed on twenty-five elite soccer-players during 26 home-matches. A total of 2565 individual samples for SSGs using different pitch sizes and different number of players were collected and classified as SSGs with (SSG-G) or without goalkeeper (SSG-P). A between-position comparison was also performed. The area-per-player needed to replicate the official match demands was largely higher in SSG-G vs SSG-P for total distance [187±53 vs 115±35 m2, effect size (ES): 1.60 95%CI 0.94/2.21], high-intensity running distance [262±72 vs 166±39 m2, ES: 1.66(0.99/2.27)] and metabolic power [177±42 vs 94±40, ES: 1.99(1.31/2.67)], but similar for sprint distance [(316±75 vs 295±99 m2, ES: 0.24(-0.32/0.79)] with direction of larger area-per-player for sprint distance > high-intensity running > total distance ≌ metabolic power for both SSG-G and SSG-P. In SSG-G, forwards required higher area-per-player than central-defenders [ES: 2.96(1.07/4.35)], wide-midfielders [ES: 2.45(0.64/3.78)] and wide-defenders [ES: 3.45(1.13/4.99)]. Central-midfielders required higher area-per-player than central-defenders [ES: 1.69(0.20/2.90)] and wide-midfielders [ES: 1.35(-0.13/2.57)]. In SSG-P, central defenders need lower area-per-player (ES: -6.01/-0.92) to overall replicate the match demands compared to all other positions. The current results may be used to gain knowledge of the SSGs relative to the match demands. This imply manipulating SSGs using higher or lower ApP, the presence of the goalkeeper or design specific rules to increase or decrease the position-specific demands with respect to the desired external load outcomes.

Comparison between continuous and discontinuous incremental treadmill test to assess velocity at V̇O2max.

BACKGROUND: The velocity associated with maximum aerobic power (vV̇O2max) is an important physiological parameter, which is utilized to determine relative workloads on the field. The testing modality adopted to evaluate it, though, may cause differences in vV̇O2max assessment and, in turn, in training intensity. The aim of the study was to compare two different testing modalities (continuous incremental ramp and discontinuous square wave (SW) protocols) for vV̇O2max assessment on the treadmill. METHODS: Seventeen physically active participants performed three maximum incremental tests on a treadmill: two continuous ramp protocols, with different ramp slopes (R1, 1 km/h every minute; and R2, 1 km/h every 2 minutes), and one discontinuous SW protocol, in random order, for maximum oxygen uptake (V̇O2max) and vV̇O2max determination. Cardiorespiratory and metabolic parameters were collected breath-by-breath at rest and during exercise. RESULTS: vV̇O2max was significantly higher in R1 and R2 compared to SW (20.7±0.5, 18.6±0.4, 16.8±0.6 km/h for R1, R2, and SW, respectively; P<0.001). No significant differences were found among protocols for V̇O2max (56.7±1.1, 57.0±1.2, and 56.6±1.2 mL/min/kg for SW, R1, R2, respectively) as well as for expiratory ventilation, carbon dioxide production, blood lactate concentration, and heart rate. CONCLUSIONS: In spite of similar V̇O2max values, vV̇O2max was higher during continuous incremental ramp tests compared to SW possibly due to the longer time for cardiorespiratory and metabolic adjustments, suggesting different aerobic and anaerobic metabolism involvement. The differences among protocols should be considered when vV̇O2max is used for training purposes.

Effects of Acute Carnosine and ß-Alanine on Isometric Force and Jumping Performance.

PURPOSE: To assess the effects of acute combined L-carnosine and ß-alanine (Carn-BA) supplementation on isometric and dynamic tasks. METHODS: Twelve healthy participants performed knee-extensor maximal voluntary contractions (MVCs) and countermovement jumps (CMJs) before and after a fatiguing protocol (45-s continuous CMJs). Isometric and dynamic tests were performed 4 h after ingestion of Carn-BA (2 g of L-carnosine and 2 g of ß-alanine) or placebo (PLA), in random order. After the fatiguing protocol, blood lactate concentration ([La-]), general and muscular rating of perceived exertion (RPE), and muscle pain (24 and 48 h after the end of the fatiguing protocol) were assessed. RESULTS: During the fatiguing protocol, significant decreases in jump height and increases in contact time were found in both groups from the 15th second onward to the end of the fatiguing protocol. Average contact time and jump height were respectively lower (-7%; P = .018) and higher (+6%; P = .025) in Carn-BA than in PLA. After the fatiguing protocol, MVC decreased in both PLA and Carn-BA, but it was higher in Carn-BA than in PLA (+15%, P = 0.012), while CMJ did not change. Moreover, general RPE was lower and muscle pain at 24 h was higher in Carn-BA than in PLA, whereas muscle RPE and [La-] did not differ between conditions. CONCLUSIONS: Ingesting Carn-BA before exercise induced positive effects on MVC and CMJ after the fatiguing protocol and improved CMJ performance during the 45-s continuous jumping effort, even when acutely supplemented. Furthermore, Carn-BA reduced the general RPE and increased muscle pain 24 h after the fatiguing task.