Handball is considered a complex highly demanding intermittent sport, since it involves multiple high-intensity runs (18,21), frequent body contact, and several other high-intensity actions to overcome opponents. Consequently, the aerobic system is highly taxed as indicated by the average (HRmean) and peak heart rate (HRmax) values (82 and 93% HRmax, respectively). Moreover, the time between each change of activity (6 seconds) and the number of intense actions and moments also suggest a high anaerobic energy turnover in certain periods of the match (18). In fact, anaerobic power seems to discriminate between elite male handball teams with different ranking (17). Additionally, although players have time to recover from intense periods throughout the match, a decline in exercise intensity has been observed in the second half of the match, suggesting that handball players probably experience fatigue during the match (18). It is well established that in other team sports such as football, performance is impaired toward the end of the game due to fatigue (2). In a previous handball study (22), a 5.2% decrease in maximal jump height and a deteriorated neuromuscular function was found after a field protocol that intended to mimic a handball match. However, the impact of the handball match on other physical capacities of importance for performance, such as the ability to sustain a high average intensity during a long period of time or to perform short-duration high-intensity exercise and possible alterations in these performance indices after certain intense periods of the match remains unknown. Actually, whether performance is reduced not only at the end of the game (persistent or permanent fatigue) but also temporarily during critical periods of the handball game (temporary fatigue) (15) is yet to be fully elucidated. Moreover, no information is available regarding the impact of real matches on neuromuscular performance in elite male handball players, and thus, it is unclear whether neuromuscular fatigue occurs since handball's rules allow unlimited substitutions. Currently, scientific research concerning elite team handball's working demands is scarce. Therefore, the purpose of the study was to examine the activity profile and physiological demands of elite male handball match-play and to investigate the degree and type of fatigue development after intense exercise periods and toward the end of the match. Our research questions are as follows: (a) does elite handball match impacts on physical and physiological indices of the players? and (b) is neuromuscular fatigue shown both temporarily and at the end of the handball match? We hypothesized that team handball players show decrements in the physical capacities tested at selected time points. The detailed characterization of the impact of the match on players' physical performance will allow the development of specific training strategies aiming to maximize performance and to optimize the physical and the physiological rationale for the need for substitutions in various stages of mach-play.
Experimental Approach to the Problem
To analyze the physical and physiological impact of the handball game, time-motion analyses and heart rate (HR) recordings were performed during 10 competitive matches for 40 players of 5 teams in the top professional Portuguese handball competition, which were regularly involved in European championships for clubs. Additionally, aiming to investigate the match-induced decrements in physical performance temporarily and at the end of the match, jump and sprint testing and Yo-Yo Intermittent Endurance level 2 test (YYIE2) (1) were performed on 18 players before a training session (baseline conditions) and after 2 competitive matches (Figure 1A). Furthermore, 12 of these players were tested during a friendly match, since blood samples collecting and sprint and jump testing after intense exercise periods within the first and second half (Figure 1A), that is, match periods, which included fast running, sprinting, or sideways high-intensity movement (adapted from reference 12), could not be performed during competitive matches. Because fluid loss and fluid intake are difficult to evaluate during competitive matches, these variables were assessed during a subsample of 5 competitive matches and also during the friendly match.
Forty outfield players (13 backcourt players, 13 wings, and 14 pivots) participated in this study, which was approved by the Institutional Review Board of the Faculty of Sport of the University of Porto (project no. 01/2004) and by the club officials, and followed the Declaration of Helsinki of the World Medical Association for research with humans. Participants were informed of the aims of the research project and made aware of the procedures, including any risks, discomforts, and benefits before giving written informed consent. The mean age, height, weight, and body fat of the players were 26 ± 3 (range, 20–37) years, 187.4 ± 8.0 (175.3–202.0) cm, 87.5 ± 7.9 (70.7–105.7) kg, and 9.6 ± 2.8 (6.0–15.0) % fat mass (Tanita Inner Scan digital BC532). At baseline conditions, the YYIE2 performance was 1466 ± 500 (880–2840) m. Participants had at least 5 years of experience in the top Portuguese handball competition. At the time of the evaluations, the players were in the middle of the competitive period, performing 6/7 training sessions per week, 4/5 comprised technical-tactical and physical fitness training exercises and 2/3 consisted of strength training.
Heart rate after 400 m of YYIE2 was higher after the game compared with before the game (180 ± 8 vs. 175 ± 7 b·min−1) (Table 2). There was a significant (p < 0.01) decrease in endurance, jump, and sprint performances after the match. Sprint performance also declined significantly during the second half (p < 0.01) (Table 2).
There was a positive association between individual playing time in the second half of matches and the decrement in the YYIE2 performance (R = 0.71; p = 0.04).
The players performed the jump test in the rested state and within 1 minute after competitive match-play and after an intense period of the first and second half of the friendly match. Two countermovement jumps (CMJ) were performed with arm swing on a Bosco's jumping mat (Ergojump Globus, Treviso, Italy). Free CMJ with extension of both upper limbs were chosen to simulate as closely as possible the spontaneous jumping movement performed in team handball matches (11). The jump height was calculated from the flight time (5). One set of 2 maximal jumps was completed, interspersed with approximately 10–15 seconds of rest between jumps and at least 90 seconds of rest between the jump and sprint test. The maximal jump height was used for further analysis.
Sprint testing was performed in the rested state and after competitive match-play and after an intense period of the first and second half of the friendly match. The test consisted of five 20-m sprints, separated by 15-second period of active recovery (adapted from reference 12) aiming to evaluate 20-m sprint performance (determined by the fasted time in the 5 sprints) and repeated sprint ability (determined by the average time in the 5 sprints). The sprint times were recorded by telemetric photoelectric cells with a precision of 0.01 seconds (Brower Timing System, IRD-T175, Utah, USA).
Yo-Yo Intermittent Endurance Level 2 Test Testing
The YYIE2 was performed in the rested state and within 5-minute after competitive match-play within at least 90 seconds after the sprint test. Three testing locations were set up to ensure this time frame. Heart rate was monitored during the test to determine HRmean, HRmax, and submaximal HR after 400 m (HRsubmax). Submaximal HR, presented as a percentage of HRmax, is a measure of the relative aerobic loading after a fixed intermittent exercise task and has been shown to provide information about team sport-specific fitness (6). All tests were completed on an indoor team handball playing court. Baseline testing occurred within 1 week before the friendly match and 1 week later the 2 competitive matches were performed (Figure 1A).
Players were advised to maintain their normal nutritional habits, and coaches were asked to continue the usual training schedule. All evaluations took place at the same time of the day.
Forty players were filmed (Sony DCR-HC20E PAL, lens—Sony VCL0625S VCL-0625S 25 mm 0.6× Wide Angle Lens Converter, Moscavide, Portugal) for the duration of all 10 competitive matches to establish game motion pattern according to the methods previously described by Póvoas et al. (18). For each locomotor category, the percentage of total time, duration, distance, and frequency were determined. The data are presented for the entire match, each half and 5-minute periods. Average time between each activity and intensity change (i.e., each change of locomotor and intensity [high and low] category, respectively) was determined. The time intervals between (a) the maximal intensity activities (i.e., sprints and sideways high-intensity movement) and between (b) the high-intensity activities were analyzed (for definitions, see reference 18).
Heart Rate Analysis
Seventy-three HR recordings of 40 outfield players (30 recordings of wings, 27 of backcourt players, and 16 pivots) were registered in 5-second intervals using Polar Team System (Polar Electro Oy, Kempele, Finland) during the 10 competitive matches. Individual maximal HR was previously determined using the YYIE2. Team handball rules allow unlimited substitutions of players throughout the match. Therefore, it is unusual that 1 athlete plays the entire match time (20). Also, a 1-minute time-out period is allowed for each team, in each half. Several other match contingencies involve the interruption of the match time (e.g., players' injuries and suspensions). Thus, HR during the match was analyzed (a) as total HR (i.e., HR during total match time) aiming to globally characterize cardiovascular demands imposed by the handball match and (b) as effective HR (i.e., HR during effective match time) aiming to describe match demands only during the time in which the player is on the playing court. In the first case, 2-minute suspensions and the half-time break were excluded from total match time. Nevertheless, in both cases, the time-outs were considered. For this purpose, the matches were filmed. Procedures regarding image collection were described above, although in this case, the players were filmed during the entire match time. The matches were held under neutral temperature (17–22° C) and humidity conditions (50–70%) (Extech Digital Hygrometer 445715; Grainger, New York, NY, USA).
Capillary blood samples (30 μl) were collected from the right earlobe at rest and at 5, 10, 15, 20, and 25 minutes and at the end of the first and the second half from 2 different players at each time point within each half (Figure 1B). Blood lactate was measured using a portable electroenzymatic lactate device analyzer (Lactate ProTM, Quesnel, Canada). Venous blood samples (5 ml) were collected from the antecubital arm vein into EDTA (EDTA-K3, Iberlab, ref. GV0414)-containing tubes at rest and immediately after the end of each half. Blood was immediately centrifuged for 10 minutes at 3000 rpm to obtain plasma. Plasma glucose concentrations were immediately determined by colorimetric method using a commercial kit (ABX A11A01668; ABX Diagnostics, Montpellier, France). The remaining plasma was then separated into aliquots and rapidly frozen at −80° C for later biochemical analysis of plasma free fatty acids (FFA), glycerol, and uric acid.
Plasma uric acid concentrations were determined through enzymatic colorimetric method at 550 nm, using a commercial kit (Horiba ABX A11A01670, ABX Diagnostics). Plasma FFA concentrations were determined by enzymatic colorimetry using a commercial kit (Wako Chemicals GmbH, Neuss, Germany). Plasma glycerol concentrations were determined by enzymatic colorimetry (Instruchemie, Delfzijl, the Netherlands). All parameters were assayed in duplicate, and the mean obtained value was used for further analysis.
Fluid Loss and Intake
To determine fluid loss during the match, the players were weighted wearing dry shorts, immediately before and after the matches using a digital balance (Tanita Inner Scan digital BC532 scale, Amsterdam, the Netherlands). The players were allowed to drink water ad libitum during the matches, and water intake was recorded.
Data reliability was assessed using a test-retest procedure after 7 days, with a random subsample of 10 subjects. The intraclass correlation coefficients (R) of all variables were high. Anthropometric measurements, 0.90 ≤ R ≤ 0.99; physical testing variables, 0.80 ≤ R ≤ 0.92, and between 0.90 ≤ R ≤ 0.95 for physiological parameters.
Results were expressed as either mean (SDs) or proportions. None of these quantitative physical and physiological parameters showed significant deviations from a normal distribution (Kolmogorov-Smirnov test). Changes in neuromuscular parameters at different time points during the handball match and differences in activity profile and HR between each 5-minute period were examined by repeated measures analysis of variance. The Bonferroni test for multiple comparisons was used. Effect size was calculated using partial eta-squared (
) and interpreted as small (≥0.01), medium (≥0.06), or large (≥0.14) (8). Differences between HR and time-motion variables during the 2 halves and performance on the YYIE2 and HR values during the test at baseline conditions and after the match were assessed by Student's paired t-test. For each of the blood metabolites and neuromuscular parameters, change scores were calculated as the difference between baseline during and after the match values; the difference was then divided by the initial value to estimate percentage or relative change (%Δ). Differences between high- and low-intensity activities, total and effective HR and between blood lactate concentrations, HR and activity profile of competitive and friendly matches were determined by Student's unpaired t-test. A significance level of 0.05 was chosen. Statistical Package for the Social Sciences (version 20.0; SPSS Inc., IBM, Armonk, New York, USA) was used for all analyses.
The total distance covered was 4.51 ± 0.63 km during the matches lasting 75 ± 4 minutes, and a total of 3.8 ± 1.4% of the playing time was spent with high-intensity running corresponding to a distance of 810 ± 356 m (17.9 ± 7.5% of the total distance covered). Standing and walking accounted for 76 ± 5% of the match time.
The total time spent in high-intensity movements during the match decreased from the first to the second half (4.4 ± 2.0 to 3.1 ± 1.7%; p ≤ 0.05). Also, the frequency of high demanding game actions decreased (p ≤ 0.05) from the first to the second half, including the number of stops (18 ± 7 to 15 ± 5), changes of movement direction (19 ± 6 to 14 ± 7), and one-on-one situations (13 ± 9 to 10 ± 8). The number of time-outs (5 ± 1 vs. 7 ± 2; p < 0.01) and time between activity changes (5.1 ± 1.3 vs. 5.6 ± 0.8; p < 0.01) increased. Time between high-intensity activities was <30 seconds and >90 seconds for 35 and 32% of the observed high-intensity bouts, respectively. Analyzed data on each 5-minute period of the match are presented in Figure 2.
Heart Rate Analysis
Effective mean HR during the match was 159 ± 17 b·min−1 (83 ± 8% HRmax), whereas total mean HR was 142 ± 29 b·min−1 (74 ± 17% HRmax) (Figure 3). Peak HR during the match was 187 ± 9 b·min−1 corresponding to 96 ± 4% HRmax. Heart rate was above 80% HRmax for 54 ± 15% of the effective match time and below 60% HRmax for only 6 ± 5%. Effective mean HR (164 ± 18 to 155 ± 19 b·min−1) and total mean HR (142 ± 35 to 133 ± 33 b·min−1) were lowered (p < 0.01) from the first to the second half, respectively. Also, the fraction of effective playing time with HRs above 80% HRmax decreased from the first to the second half (62 ± 21 to 41 ± 17%, respectively; p ≤ 0.05).
Intensity of the Matches
No significant differences were observed in the total distance covered (4.74 ± 0.62 vs. 4.51 ± 0.63 km; p = 0.09), percentage of high-intensity activity performed (3.9 ± 1.7 vs. 3.8 ± 1.4%; p = 0.32), effective mean HR (85 ± 4 vs. 83 ± 8% HRmax; p = 0.16), or HRpeak (97 ± 3 vs. 96 ± 4% HRmax; p = 0.23) between the friendly match and the competitive matches.
Average blood lactate during the friendly match was 3.6 ± 2.1 (1.3–8.6) mM (Table 1), and peak values were 8.0 ± 1.4 (range, 6.7–8.6) mM.
Fluid Loss and Intake
The average body mass loss during the matches was 0.8 ± 0.4 (0.0–1.6) kg corresponding to 0.9 ± 0.5 (0.0–1.6) % of the body mass and the fluid intake was 1.3 ± 0.3 (0.7–1.6) L. Thus, the average fluid loss during the matches was 2.1 ± 0.5 (1.5–2.9) L, corresponding to 2.3 ± 0.4 (1.9–3.2) % of the body mass. There was no significant association between effective HRmean or HRpeak and fluid lost during the analyzed matches (R = 0.21; p = 0.52; R = 0.16; p = 0.69, respectively).
This study provides, for the first time, combined information on the activity profile, physiological demands and performance decrements during elite male handball matches. The results show that the HRs were high during a majority of the playing time and that the amount of high-intensity running and the number of specific intense actions decreased from the first to the second half. Blood lactate was elevated 3- to 4-fold during the match compared with baseline, with no difference between halves, whereas plasma FFA and glycerol increased throughout the game. Altogether, these results show that elite handball match impacts on physical and physiological indices of the players. Sprint performance was lowered after an intense period of the second half and YYIE2, jump and sprint performance was deteriorated after the match, which provides evidence that fatigue occurs both temporarily during the second half and toward the end of match-play for elite male handball players. As mentioned above and as will be highlighted in the Practical Applications section, the present results reinforce the need of coaches for designing high-intensity, short-duration, and short-time recovery exercises such as repeated sprints, jumps, pulling/drift actions, and contacts during both conditioning and mixed (tactical and physical-based) training sessions, regardless of the fact that handball rules allow unlimited number of substitutions.
The mean HR during the effective playing time was high both for the investigated competitive games and for the friendly game (83 and 85% HRmax) with 54 and 83% of the effective playing time with HRs above 80% HRmax. The peak HRs reached during the competitive games and the friendly game approached maximal values (96% HRmax). The locomotor analyses revealed that about two-thirds of the overall game time was spent standing and jogging. However, the results show that multiple intense running bouts (401 and 520) and numerous specific intense actions (115 and 123) are performed during competitive and friendly handball match-play. A friendly match was used since blood samples collection and neuromuscular performance evaluation could not be performed during competitive matches, so it should be considered to what extent it represents the intensity of official matches. However, there were no significant differences between HR values and activity profile of the friendly and the official matches, and altogether the levels of high-intensity activity and HR confirmed the relative high intensity of the friendly match. Also, there were no significative differences between the time spent on high-intensity running in the 5-minute periods before blood sampling and physical performance evaluation in the friendly game and in the most intense 5-minute periods of the competitive games (4.4 ± 4.6 vs. 5.7 ± 3.8%; p = 0.19).
Our results showed a decrease in the distance covered with high-intensity running from the first to the second half as well a reduction in the number of specific intense actions such as stops, changes of movement direction, and one-on-one situations. This study also showed that the YYIE2, sprint, and jump performance decreased after the game, which provides direct evidence of fatigue. The intermittent high-intensity exercise performance as evaluated by YYIE2 was lowered by as much as 33%. To the best of our knowledge, this test has not previously been used to evaluate the fatigue development during elite handball, but studies on elite female football players and high-level junior male football players have shown decreases in YYIE2 performance of 40–60% after match-play (14,19). This study also showed a 1.6% decline in 20-m sprint performance after the game, but no change in repeated sprint ability contrasting with elite male footballers in which single and repeated sprint performance decreased 2–7% after friendly, competitive matches and simulated football match-play (4,14,15). However, the observed decrease in jump performance was as high as 7.4% after match-play, which is similar to values reported for elite handball matches with female (6.7%) (20) and male players (5.2%) (22). Also, the number of sprints is lower, whereas the number of jumps and other intense actions requiring a high muscle tension are high in team handball. Local muscle fatigue after a simulated handball match was suggested by Thorlund et al. (22), reporting a 11% reduction in maximal voluntary contraction force of the knee-extensors in elite male players. Performance decrements toward the end of elite football matches have been suggested to be related to glycogen depletion in a large fraction of the individual muscle fibers (12). However, it is yet to be examined whether the glycogen utilization during a 60-minute team handball match is sufficiently high to cause glycogen depletion of individual muscle fibers. Although the average blood lactate values were lower than what has been reported for elite male footballers (3.2 vs. 4.8 mM) (2,3,12), the individual peak values ranged from 7–9 mM indicating periods with high glycogen utilization. Moreover, we observed a 5-fold increase in plasma FFA and a 6-fold increase in plasma glycerol during the game, suggesting a strong activation of the lipid metabolism. Glucose levels remained high and stable during the game, rejecting the possibility of hypoglycemia (10) and suggesting that increased glucose uptake during the game is compensated by glucose release from the liver. Also, dehydration and hyperthermia have been suggested to contribute to fatigue development toward the end of the game (2). Nonetheless, the analyzed matches were performed in thermoneutral conditions, and the average body mass loss was less than 1 L, suggesting a minor impact on HR and cardiovascular strain (9). Also, no relationship was observed between HRpeak and HRmean and fluid loss. However, the HRsubmax during the YYIE2 was more than 5 b·min−1 higher after than before the game, suggesting a slightly lowered stroke volume due to the fluid loss during the game and/or a lower economy of intermittent running after the game. This value is lower than the test-retest CV reported for HRsubmax during this test (7).
In this study, it was also investigated whether fatigue occur after intense exercise periods in the first and second half. The sprint performance was lower after an intense exercise period in the second half compared with resting condition. However, no changes were observed in jump performance or repeated sprint ability after intense periods of the first and second half. As mentioned, the peak blood lactate of 7–9 mM indicates periods with very high anaerobic energy turnover. The time-motion analyses showed that about one-third of the time between intense runs lasted less than 30 seconds but also that another one-third of the intense runs were performed more than 90 seconds after the last high-intensity activity. Together, the findings may explain why the running pattern in team handball results in temporary fatigue, as performance changes may occur after very intense exercise and as the long recovery periods allow for recovery. The causes of temporary fatigue in team sports are under debate but may relate to disturbances in muscle ion homeostasis, particularly potassium (K+) and calcium ions. Recent studies have indicated large increases in muscle interstitial K+ during progressive intermittent exercise and football match-play (4,12,16), as indicated by increases in plasma K+ concentrations. Furthermore, K+ handling in the muscle cell has been shown to be deteriorated after a football game (13). However, no such measurements were performed in this study, and further studies are required to elucidate the degree of and mechanisms behind temporary fatigue in elite handball. One limitation of this study is that the analysis did not take into account the playing position as it has been showed that HR and locomotor profile during games show considerable variation among players (18), suggesting that position-related differences might contribute to this variation. Nevertheless, no significant differences were observed between the playing positions in the biochemical response and physical performance alterations during and after the match. Thus, further studies comprising a higher sample size should be performed.
In conclusion, the aerobic demands were high during most of the handball game interspersed with periods of high lactate production and therefore, with short but high anaerobic requirements. Less high-intensity running and specific intense actions were performed in the second half of the game, and jumping ability, sprinting speed, and progressive intermittent exercise performance were lowered immediately after the game. Moreover, sprint performance was observed to be lowered after an intense period in the second half. Together, the present results indicate that elite handball matches are physically demanding and that the players experience temporary and permanent fatigue during match-play.
This study identifies the physical demands and the fatigue development profile in elite team handball. These findings enable physical trainers and coaches to plan and properly design game-specific training exercises and strengthen the physiological rationale for the need for substitutions in various stages of match-play. From a practical point of view, the present results suggest that, regardless of the fact that the handball rules permit unlimited number of substitutions at any given time during the match, physical coaches should consider specific physical conditioning or combined (technique-based, tactical, or mixed) training exercises comprising repeated sprints, jumps, pulling/drift actions, and contacts with high-intensity, short-duration, and short-time recovery. These exercises target improvements in handball-specific physical fitness, delaying neuromuscular fatigue both temporarily after certain high-intensity periods of the game and toward the end of the game. The design of specific weight-bearing resistance training exercises or small-sided games by physical coaches should also consider the referred intensity, duration, and recovery time relationship. Additionally, given the decrement of performance in the second half of matches, substitutions can be used as an effective tool to enhance recovery and thus minimizing neuromuscular fatigue. Friendly matches should be used to test the use of frequent substitutions without affecting the team tactics.
The authors thankfully acknowledge to all the elite handball players and coaches who participated on this study. They are also grateful to Dr. Franklim Marques from the Clinical Analysis Service in the Faculty of Pharmacy, University of Porto, for the kind assistance in the biochemical assays. They also thank Dr. Sarah R. Jackman for editing the article. The authors are supported by Grants from the Portuguese Foundation for Science and Technology (SFRH/BD/38148/2007, SFRH/BPD/4225/2007, and SFRH/BPD/66935/2009). The results of this study do not reflect any endorsement by the National Strength and Conditioning Association.
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