International  Journal  of
Environmental Research
and Public Health
Article
Exercise Intensity and Technical Involvement in U9 Team
Handball: Effect of Game Format
Georgios Ermidis 1
, Rasmus C. Ellegard 2
, Vincenzo Rago 3
, Morten B. Randers 2,4
, Peter Krustrup 2
and Malte N. Larsen 2,*


Citation: Ermidis, G.; Ellegard, R.C.;
Rago, V.; Randers, M.B.; Krustrup, P.;
Larsen, M.N. Exercise Intensity and
Technical Involvement in U9 Team
Handball: Effect of Game Format. Int.
J. Environ. Res. Public Health 2021, 18,
5663. https://doi.org/10.3390/
ijerph18115663
Academic Editors: Filipe
Manuel Clemente and
Hugo Sarmento
Received: 31 March 2021
Accepted: 21 May 2021
Published: 25 May 2021
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1
Department of Movement and Wellness Sciences, University of Naples “Parthenope”, 80133 Naples, Italy;
germidis1990@gmail.com
2
Department of Sports Science and Clinical Biomechanics, SDU Sport and Health Sciences Cluster (SHSC),
University of Southern Denmark, 5230 Odense, Denmark; Rasmuscyril@hotmail.com (R.C.E.);
mranders@health.sdu.dk (M.B.R.); pkrustrup@health.sdu.dk (P.K.)
3
Faculty of Health and Sport Sciences, Universidade Europeia, 1500-210 Lisbon, Portugal;
vincenzo.rago@universidadeeuropeia.pt
4
School of Sports Sciences, UiT The Arctic University of Norway, 9037 Tromsø, Norway
*
Correspondence: mnlarsen@health.sdu.dk
Abstract: The purpose of this study was to quantify the exercise intensity and technical involvement
of U9 boys’ and girls’ team handball during different game formats, and the differences between
genders. Locomotor activity (total distance, distance in speed zones, accelerations, and decelerations),
heart rate (HR), and technical involvement (shots, goals, and duels) metrics were collected during
various 15 min game formats from a total of 57 Danish U9 players (37 boys and 20 girls). Game
formats were a small size pitch (20 × 13 m) with 3 vs. 3 players and offensive goalkeepers (S3 + 1)
and 4 vs. 4 players (S4), a medium size pitch (25.8 × 20 m) with 4 vs. 4 (M4) and 5 vs. 5 (M5) players,
and a large size pitch (40 × 20 m) with 5 vs. 5 (L5) players. Boys and girls covered a higher total
distance (TD) of high-speed running (HSR) and sprinting during L5 games compared to all other
game formats (p < 0.05; ES = (−0.9 to −2.1), (−1.4 to −2.8), and (−0.9 to −1.3) respectively). Players
covered the highest amount of sprinting distance in L5 games compared to all other game formats
(p < 0.01; ES = 0.8 to 1.4). In all the game formats, players spent from 3.04 to 5.96 min in 180–200 bpm
and 0.03 min to 0.85 min in >200 bpm of the total 15 min. In addition, both genders had more shots
in S3 + 1 than M5 (p < 0.01; ES = 1.0 (0.4; 1.7)) and L5 (p < 0.01; ES = 1.1 (0.6; 2.2)). Team handball
matches have high heart rates, total distances covered, and high-intensity running distances for U9
boys and girls irrespective of the game format. Locomotor demands appeared to be even higher
when playing on larger pitches, whereas the smaller pitch size and fewer players led to elevated
technical involvement.
Keywords: physiology; youth; heart rate; time motion; notational analysis
1. Introduction
Team handball is an intermittent high-intensity body contact team sport, characterized
by sprinting, jumping, throwing, blocking, and pushing [1]. Various studies have described
the locomotor demands of team handball in different age and sex groups; on average, inter-
national male players cover 4370 ± 702 m [2], elite female players cover 4002 ± 551 m [3],
and elite male adolescent players (15 years old) cover 1777 ± 264 m [4]. Overall, the
physical and physiological demands, and therefore, the potential as a health-promoting
activity of team handball have been predominantly investigated in adults and adolescent
players [5]. Only one study investigated U13 boys and girls across different formats [6].
Youth team handball games in Denmark are played on different pitch dimensions and
with a different number of players compared to adult games, similar to other team sports
such as football [7]. For instance, in youth team handball games, the pitch and goal di-
mensions are smaller and the number of players is reduced. Extensive research in other
Int. J. Environ. Res. Public Health 2021, 18, 5663. https://doi.org/10.3390/ijerph18115663
https://www.mdpi.com/journal/ijerph
Int. J. Environ. Res. Public Health 2021, 18, 5663
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team sports showed that manipulating the player numbers and the pitch size can alter
the exercise intensity (i.e., locomotor activity, physiological responses) during a game in
different sports [8]. Indeed, higher exercise intensity (e.g., heart rate (HR)) is reached when
decreasing the number of players and increasing the pitch area [9]. On the other hand,
reducing the number of players and pitch dimensions appears to induce higher technical
involvement [7,10].
Moreover, the sex-speciﬁc timing of maturation [11,12] and the gender differences
in morphological and neuromuscular characteristics are still early at this stage of age,
and gender-related differences in explosive actions are therefore unlikely. Investigating
differences in exercise intensity between gender may provide practitioners with a greater
understanding of sex-speciﬁc training prescription. Overall, several external factors can
inﬂuence the physiological and technical demands of training drills and thus, the desired
conditioning stimulus [13]. Thus, information regarding the exercise intensity in children
of both genders across different game formats could be of interest for practitioners involved
with youth handball.
Based on previous ﬁndings in a study of the game format of U13 handball [6], we
hypothesized that a larger court will increase the total distance and that fewer players on
the court will increase the involvement of the players in terms of more shots and duels
per player.
The purpose of this study was, therefore, to quantify the exercise intensity, the technical
involvement, and a gender comparison of U9 boys’ and girls’ team handball during
different game formats. The study provides useful knowledge that might change the game
format used in tournaments for U9 players for relevant development and health promotion.
2. Materials and Methods
2.1. Design
U9 players from ten Danish teams (local handball clubs around the region of Funen)
participated in a 1-day tournament. Up to 5 games per player were used. Game formats
were classiﬁed according to the pitch size and number of players that represent possible
ofﬁcial games:
•
(S3 + 1): 3 vs. 3 + offensive goalkeepers on a small size pitch size of 20 × 13 m (37 m2
per player);
•
(S4): 4 vs. 4 on a small size (33 m2 per player);
•
(M4): 4 vs. 4 on a medium size pitch size of 25.8 × 20 m (65 m2 per player);
•
(M5): 5 vs. 5 on a medium size (52 m2 per player);
•
(L5): 5 vs. 5 on a large size pitch size of 40 × 20 m (80 m2 per player).
In all of the above formats, goalkeepers participated, but they only were tracked
in S3 + 1. To remove the effect of exercise volume and fatigue, the game duration was
maintained at 15 min, and the games were played in a randomized order on the same
day. All games were played on indoor team handball pitches. The sizes of the goals were
1.6 × 2.4 m on the small pitch, 1.78 × 3 m on the medium pitch, and 2 × 3 m on the large
pitch. The games were played with all the ofﬁcial rules of the team handball game. The
study was carried out according to the Helsinki protocol.
2.2. Participants
Six teams of U9 boys (n = 37) and four teams of U9 girls (n = 20) participated in the
study. All participants were 8–9-year-old recreational handball players.
2.3. Activity Proﬁle
The activity patterns were recorded using a wearable device incorporating a 200 Hz
accelerometer and gyroscope (Polar Team Pro system, Polar, Kempele, Finland), which
was placed on the lower sternum using an elastic band. The following variables were
adopted: total distance (TD) covered, peak speed (Vpeak) attained, and number of sprints
(>18 km/h). Exercise intensity was also distributed in the following running zones: stand-
Int. J. Environ. Res. Public Health 2021, 18, 5663
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ing/walking (St/W; 0.00–2.99 km/h), jogging (3.00–7.99 km/h), moderate-speed running
(MSR, 8.00–12.99 km/h), high-speed running (HSR, 13.00–17.99 km/h), and sprinting
(>18 km/h), according to previous studies describing the locomotor demands of team
sports’ children [14,15].
In addition, the number of accelerations and decelerations were measured with the fol-
lowing zones: Acc < 1.49 m·s−2, Acc 1.50 to 2.30 m·s−2, Acc > 2.30 m·s−2, Dec < −1.49 m·s−2,
Dec −1.50 to −2.30 m·s−2, and Dec < −2.30 m·s−2 [14,15]. The total number of acceler-
ations and decelerations was also quantiﬁed. The activity proﬁles and HR data were
stored in the device and downloaded using the manufacturer’s software (POLAR, software
version 1.3.1, POLAR, Polar Electro Oy, Kempele, Finland) [16].
2.4. Heart Rate and Subjective Perceptions
HRs were recorded in 1 s intervals during each game. The HR data were downloaded
and expressed as the mean and max HR for the full match. In addition, the HR data
were expressed as the time spent in HR zones as follows: <120, 120 to 160, 160 to 180,
180 to 200, and >200 bpm, as previously described [7]. Furthermore, after each game,
a Visual Analogue Scale was used to assess the rating of perceived exertion (RPE) and
enjoyment/fun (RPF), as previously done in similar studies since it is a well-accepted
method to describe subjective phenomena [17,18]. Immediately after the 15 min matches,
every player had a paper and pencil to record their scores. All players underwent a brief
familiarization session in which three researchers explained the procedure, underlining the
importance of scoring their perception of exertion (not fatigue or tiredness). For physical
exertion, the players placed a mark on a 17.4 cm line ranging from ‘maximally demanding’
to ‘not demanding at all’, while for perceived fun, a similar line was used, ranging from
‘maximal fun’ to ‘not fun at all’. The result was obtained by measuring with a ruler the
length (in centimeters) from 0 to the mark made by the player.
2.5. Technical Analysis
Notational analysis was performed by video analysis by ﬁve experienced handball
coaches (an observer-to-player ratio of 1:1) engaged by the Danish Handball Federation
(DHF). The operational deﬁnitions of these variables were the following: goal (an attempt
with successful scoring), shot (an attempt to score a goal made with any (legal) part of the
body, either on or off-target), successful shot (an attempt that successfully scores a goal,
given by the ratio between goals and shots and expressed as a percentage), 1 vs. 1 duels
(offensive breakthrough to an opponent with the ball) [19,20].
2.6. Statistical Analyses
Differences between game formats and between sexes were analyzed using a linear
mixed model with unstructured covariance, considering the fact that participants differed
regarding the number of game formats they participated in [21]. The game format was set
as a ﬁxed effect and the individual subjects and teams were set as random effects. Physical,
physiological, and perceptual variables were dependent variables. If a signiﬁcant effect was
found, a pairwise comparison was tested using the Bonferroni post-hoc test. Magnitude-
based inferences were adopted to interpret differences between game formats and sexes [22].
Effect sizes (ES) were calculated using mean differences and pooled standard deviation,
and classiﬁed according to Hopkins and Marshall [22] as following: trivial (ES < 0.2),
small (ES = 0.2–0.6), moderate (ES = 0.6–1.2), large (ES = 1.2–2.0), very large (ES = 2.0–4.0),
and huge (ES > 4.0). When 90% conﬁdence intervals overlapped positive and negative
values, the effect was deemed as unclear. Otherwise, the effect was deemed as the observed
magnitude [23]. Signiﬁcance was set at p ≤ 0.05. Data analysis was performed using the
Statistical Package for Social Science statistical software (version 23, IBM SPSS Statistics,
Chicago, IL, USA) and an online-available Excel spreadsheet [24].
Int. J. Environ. Res. Public Health 2021, 18, 5663
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3. Results
3.1. Activity Proﬁle
Boys covered more TD, HSR, and sprinting and performed more sprints in L5 com-
pared to S3 + 1, S4, M4, and M5 (p < 0.05; ES = 0.9 to 1.9). Moreover, the TD was moderately
higher in S3 + 1 compared to M5 (p = 0.026; ES = 0.9 [0.4; 1.3]). Higher peak speed were
reached during L5 compared to S4 and M5 (p = 0.01; ES = 0.9 to 1.1) (Table 1) (Figure 1A).
Table 1. Differences in peak and average values and total distance between game formats.
Variables (U9)
Sex
S3 + 1
S4
M4
M5
L5
Activity proﬁle
TD (m)
Boys
1133 ± 171
988 ± 141
1106 ± 157
977 ± 172 a
1320 ± 232 a,b,c,d
Girls
965 ± 195
878 ± 159
999 ± 156
846 ± 124 c
1125 ± 134 a,b,d
Vpeak (km·h−1)
Boys
21.4 ± 3.2
20.1 ± 3.0
22.4 ± 3.1
20.7 ± 2.8
23.6 ± 3.0 b,d
Girls
19.0 ± 2.3
19.5 ± 2.6
19.5 ± 2.8
19.9 ± 2.7
21.6 ± 2.4 a
Sprints (counts)
Boys
5.1 ± 5.4
2.9 ± 3.6
5.8 ± 5.2
4.6 ± 5.5
11.9 ± 7.5 a,b,c,d
Girls
2.9 ± 3.5
1.5 ± 1.5
2.4 ± 2.6
2.7 ± 2.5
8.4 ± 7.6 a,b,c,d
Acctotal (counts)
Boys
212.0 ± 20.3
209.0 ± 21.2
200.7 ± 20.0
186.1 ± 21.6 a,b
172.2 ± 23.2 a,b,c,d
Girls
198.0 ± 14.4
197.1 ± 25.3
200.3 ± 21.4
177.4 ± 21.7 a,b,c
160.7 ± 15.0 a,b,c,d
Dectotal (counts)
Boys
219.8 ± 17.3
209.8 ± 21.7
203.6 ± 17.8
191.5 ± 19.7 a,b,c
182.7 ± 24.0 a,b,d
Girls
201.1 ± 18.1
197.1 ± 26.4
204.1 ± 17.8
184.7 ± 20.9 a,b,c
173.2 ± 13.6 a,b,d
Heart rate
HRavg (bpm)
Boys
175.8 ± 10.3
165.9 ± 11.2
167.9 ± 11.5
165.8 ± 13.1
169.7 ± 14.8
Girls
174.7 ± 10.2
171.1 ± 9.7
168.8 ± 11.1
164.6 ± 13.5
172.8 ± 8.7
HRpeak (bpm)
Boys
195.1 ± 10.3
185.6 ± 10.1 a
192.3 ± 10.5
189.2 ± 11.6
191.2 ± 11.1
Girls
196.3 ± 8.6
191.9 ± 11.4
189.4 ± 9.5
186.1 ± 12.8
192.3 ± 8.3
Subjective perceptions
RPE (AU)
Boys
8.4 ± 3.8
10.2 ± 4.2
8.5 ± 4.1
9.2 ± 5.2
6.9 ± 4.9
Girls
6.9 ± 3.3
10.1 ± 3.0
6.4 ± 3.3
6.8 ± 4.4
6.5 ± 4.8
RPF (AU)
Boys
4.3 ± 4.6
5.2 ± 4.7
5.2 ± 4.3
4.5 ± 5.1
5.0 ± 5.4
Girls
3.8 ± 2.7
5.0 ± 3.7
5.1 ± 2.8
5.4 ± 3.6
4.1 ± 4.7
Data are mean ± SD. S3 + 1: small size, 3 vs. 3 + offensive goalkeeper; S4: small size, 4 vs. 4; M4: medium size, 4 vs. 4; M5: medium
size, 5 vs. 5; L5: large size, 5 vs. 5. Acctotal: total accelerations; Dectotal: total decelerations; HRavg: average heart rate; HRpeak: peak heart
rate; TD: total distance; Vpeak: peak speed attained; RPE: rating of perceived exertion; RPF: rating of perceived enjoyment/fun. a denotes
signiﬁcant differences compared to S3 + 1; b to S4; c to M4; d to M5 (p ≤ 0.05).
Int. J. Environ. Res. Public Health 2021, 18, 5663 
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Figure 1. Distance covered in different speed zones in U9 (A) boy and (B) girl handball players by game formats. S3 + 1: 
small size, 3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; L5: large size, 
5 v 5. St/W: standing/walking; MSR: moderate-speed running; HSR: high-speed running. a denotes significant differences 
compared to S3 + 1; b to S4; c to M4; d to M5 (p ≤ 0.05). 
Furthermore, number of Acctotal and Dectotal were lower in L5 compared to S3 + 1, S4, 
and M4 (p < 0.05; ES = 0.6 to 1.8). In addition, M5 exhibited lower number of Acctotal and 
Dectotal than S3 + 1 and S4 (p < 0.05; ES = 0.8 to 1.5). The numbers of Acc<1.5 and Acc1.5–2.3 
were lower during L5 compared to S3 + 1, S4, and M4 (p < 0.05; ES = 0.7 to 1.6). Conversely, 
the number of Acc<1.5 was moderately higher in S4 compared to M5 (p = 0.033; ES = 0.8 (0.3; 
1.3)), and the number of Acc1.5–2.3 was largely higher in S3 + 1 than M5 (p < 0.01; ES = 1.4 
Figure 1. Distance covered in different speed zones in U9 (A) boy and (B) girl handball players by game formats. S3 + 1:
small size, 3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; L5: large size,
5 v 5. St/W: standing/walking; MSR: moderate-speed running; HSR: high-speed running. a denotes signiﬁcant differences
compared to S3 + 1; b to S4; c to M4; d to M5 (p ≤ 0.05).
Int. J. Environ. Res. Public Health 2021, 18, 5663
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Girls covered more TD during L5 compared to S3 + 1, S4, and M5 (p < 0.05; ES = 0.9–2.1).
In addition, the TD was moderately higher in M4 compared to M5 (p = 0.043; ES = 1.0
[0.4; 1.6]). Higher peak speed were reached during L5 compared to S3 + 1 (p = 0.044;
ES = 1.0 [1.6; 0.4]). Girls covered more HSR and sprinting and performed more sprints in
L5 compared to S3 + 1, S4, M4, and M5 (p < 0.05; ES = 0.8 to 2.9) (Table 1) (Figure 1B).
Furthermore, number of Acctotal and Dectotal were lower in L5 compared to S3 + 1, S4,
and M4 (p < 0.05; ES = 0.6 to 1.8). In addition, M5 exhibited lower number of Acctotal and
Dectotal than S3 + 1 and S4 (p < 0.05; ES = 0.8 to 1.5). The numbers of Acc<1.5 and Acc1.5–2.3
were lower during L5 compared to S3 + 1, S4, and M4 (p < 0.05; ES = 0.7 to 1.6). Conversely,
the number of Acc<1.5 was moderately higher in S4 compared to M5 (p = 0.033; ES = 0.8 (0.3;
1.3)), and the number of Acc1.5–2.3 was largely higher in S3 + 1 than M5 (p < 0.01; ES = 1.4
(0.8; 1.9)). Notably, lower number of decelerations were observed during L5 compared
to S3 + 1, S4, and M4 (p < 0.05; ES = 1.0 to 1.3). Furthermore, higher number of Dec1.5–2.3,
were observed in S3 + 1 compared to M5 and L5 (p < 0.05; ES = 0.9 to 1.3). Additionally, S4
showed higher number of Dec1.5–2.3 than M5 (p = 0.042; ES = 0.9 (0.4; 1.3)). S3 + 1 showed
higher number of Dec>2.3 than M5 (p = 0.019; ES = 0.8 (0.3; 1.3)).
For girls, number of Acctotal and Dectotal were lower in L5 compared to S3 + 1, S4, and
M4 (p < 0.05; ES = 1.2 to 2.5). In addition, M5 exhibited lower number of Acctotal than S3 + 1,
S4, and M4 (p < 0.05; ES = 0.8 to 1.0). M5 had moderately lower number of Dectotal than
M4 (p = 0.047; ES = 0.9 (0.3; 1.5)). Girls had lower number of Acc<1.5 during L5 compared
to S3 + 1, S4, M4, and M5 (p < 0.05; ES = 1.1 to 1.8). Similarly, during L5, girls had lower
number of Acc1.5–2.3 than S3 + 1, S4, and M4 (p < 0.05; ES = 1.1 to 2.1). In addition, Acc1.5–2.3
had fewer efforts in M5 than in S3 + 1 and S4 (p < 0.05; ES = 0.8 to 1.4). In Dec1.5–2.3, L5
had lower number of efforts than S3 + 1, S4, and M4 (p < 0.05; ES = 1.0 to 1.5). In addition,
Dec1.5-2.3 in S3 + 1 had higher number than M5 (p = 0.002; ES = 1.2 [0.6; 1.8]). Detailed
representations of accelerations and decelerations are reported in Figures 2 and 3.
3.2. Heart Rate and Subjective Perceptions
Boys attained higher HRpeak in S3 + 1 compared to S4 (p = 0.029; ES = 0.9 (0.4; 1.4))
(Table 1). In addition, boys spent more time within 180–200 bpm in S3 + 1 than in S4
(p = 0.045; ES = 0.8 (0.3; 1.3)) (Figure 4). No signiﬁcant differences were found between
game formats in the RPEs and RPFs of boys (p > 0.05). Girls had higher times below
120 bpm during S3 + 1 compared to M4 and L5 (p < 0.05; ES = 1.3 to 1.6) (Table 1). In
addition, girls spent more time between 120–160 bpm in M5 than S3 + 1 (p = 0.028; ES = 0.9
(0.3; 1.5)) (Figure 4). No signiﬁcant differences were found between game formats in the
RPEs and RPFs for girls (p > 0.05) (Table 1).
3.3. Technical Analysis
For the total number of shots, more shots occurred in S3 + 1 and S4 compared to
M5 and L5 (p < 0.05; ES = 0.8 to 1.1). In contrast, no differences were observed for goals,
successful shots, or duels in all the formats. For girls, the total amount of goals was higher
in S3 + 1 than in M4, M5, and L5 (p < 0.05; ES = 0.9 to 1.3), as well as in S4 compared to M5
(p = 0.029; ES = 1.3 (0.3; 1.6)). In addition, situation S3 + 1 had more shots than M5 and L5
(p < 0.05; ES = 1.0 to 1.6). Furthermore, girls were less successful with shots in M5 than in
S3 + 1 and S4 (p < 0.05; ES = 0.9 to 1.6) (Table 2).
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Figure 2. Number of accelerations in U9 (A) boy and (B) girl handball players by game formats. S3 
+ 1: small size, 3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: me-
dium size, 5 v 5; L5: large size, 5 v 5. a denotes significant differences compared to S3 + 1; b to S4; c 
to M4; d to M5 (p ≤ 0.05). 
Acc < 1.5
Acc 1.5 – 2.3
Acc > 2.3
0
60
120
180
Number of accelerations (n)
S3+1
S4
M4
M5
L5
A)
a,b,c
b
a
a,b,c
Acc < 1.5
Acc 1.5 – 2.3
Acc > 2.3
0
60
120
180
Number of accelerations (n)
S3+1
S4
M4
M5
L5
B)
a,b,c,d
a,b
a,b,c
Figure 2. Number of accelerations in U9 (A) boy and (B) girl handball players by game formats. S3 + 1: small size,
3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; L5: large size, 5 v 5.
a denotes signiﬁcant differences compared to S3 + 1; b to S4; c to M4; d to M5 (p ≤ 0.05).
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Figure 3. Number of decelerations in U9 (A) boy and (B) girl handball players by game formats. S3 
+ 1: small size, 3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: me-
dium size, 5 v 5; L5: large size, 5 v 5. a denotes significant differences compared to S3 + 1; b to S4; c 
to M4 (p ≤ 0.05). 
3.2. Heart Rate and Subjective Perceptions 
Boys attained higher HRpeak in S3 + 1 compared to S4 (p = 0.029; ES = 0.9 (0.4; 1.4)) 
(Table 1). In addition, boys spent more time within 180–200 bpm in S3 + 1 than in S4 (p = 
0.045; ES = 0.8 (0.3; 1.3)) (Figure 4). No significant differences were found between game 
f
t i
th RPE
d RPF
f b
(
> 0 05) Gi l h d hi h
ti
b l
120 b
Dec < -1.5
Dec -1.5  – -2.3
Dec < -2.3
0
60
120
180
Number of decelerations (n)
A)
S3+1
S4
M4
M5
L5
a,b,c
a,b
a
a
Dec < -1.5
Dec -1.5 – -2.3
Dec < -2.3
0
60
120
180
Number of decelerations (n)
B)
S3+1
S4
M4
M5
L5
a
a,b,c
Figure 3. Number of decelerations in U9 (A) boy and (B) girl handball players by game formats. S3 + 1: small size,
3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; L5: large size, 5 v 5.
a denotes signiﬁcant differences compared to S3 + 1; b to S4; c to M4 (p ≤ 0.05).
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Figure 4. Heart rate distribution during U9 (A) boy and (B) girl handball games. S3 + 1: small size, 
3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; 
L5: large size 5 v 5. a denotes significant differences compared to S3 + 1 (p ≤ 0.05). 
3.3. Technical Analysis 
For the total number of shots, more shots occurred in S3 + 1 and S4 compared to M5 
and L5 (p < 0.05; ES = 0.8 to 1.1). In contrast, no differences were observed for goals, suc-
cessful shots, or duels in all the formats. For girls, the total amount of goals was higher in 
S3 + 1 than in M4, M5, and L5 (p < 0.05; ES = 0.9 to 1.3), as well as in S4 compared to M5 (p 
Figure 4. Heart rate distribution during U9 (A) boy and (B) girl handball games. S3 + 1: small size, 3 v 3 + offensive
goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; L5: large size 5 v 5. a denotes signiﬁcant
differences compared to S3 + 1 (p ≤ 0.05).
Int. J. Environ. Res. Public Health 2021, 18, 5663
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Table 2. Differences in technical demands between game formats. Data are mean ± SD.
Variables
Sex
S3 + 1
S4
M4
M5
L5
Shots (counts)
Boys
7.0 ± 4.1
6.4 ± 3.9
4.9 ± 3.3
3.5 ± 2.6 a,b
3.2 ± 2.1 a,b
Girls
7.4 ± 3.5
6.0 ± 5.2
4.7 ± 2.8
3.8 ± 3.0 a
2.8 ± 2.0 a
Goals (counts)
Boys
2.5 ± 2.4
2.2 ± 2.1
2.0 ± 2.0
1.1 ± 1.3
1.1 ± 1.0
Girls
3.9 ± 2.9
2.4 ± 1.5
1.6 ± 1.4 a
0.7 ± 0.9 b
1.0 ± 1.3 a
Successful shots (counts)
Boys
35.2 ± 29.2
34.7 ± 23.9
38.0 ± 30.1
29.2 ± 32.0
32.2 ± 28.9
Girls
53.7 ± 23.9
47.4 ± 41.3
35.3 ± 25.8
15.4 ± 22.5 a,b
31.0 ± 38.9
Duels (counts)
Boys
1.1 ± 1.2
0.7 ± 1.3
0.7 ± 1.1
0.5 ± 0.9
0.4 ± 0.6
Girls
1.7 ± 2.8
1.6 ± 2.1
1.2 ± 1.7
0.6 ± 1.0
0.6 ± 1.2
Data are mean ± SD. S3 + 1: small size, 3 vs. 3 + offensive goalkeeper; S4: small size, 4 vs. 4; M4: medium size, 4 vs. 4; M5: medium size,
5 vs. 5; L5: large size, 5 vs. 5. a denotes signiﬁcant differences compared to S3 + 1; b to S4.
3.4. Gender
The boys covered more TD in S3 + 1, S4, M5, and L5 compared to the girls (p < 0.05;
ES = 0.8 to 0.9). Furthermore, the boys reached higher Vpeak during S4 and M5 compared
to the girls (p < 0.05; ES = 0.7 to 0.9). Moderate higher sprints were observed in the M4
format for boys compared to girls (p = 0.020; ES = 0.7 [0.2; 1.3]). Notably, the jog distance
was higher for boys during S3 + 1, S4, M4, M5, and L5 compared to girls (p < 0.05; ES = 0.6
to 1.2). In addition, sprinting in M4 and L5 was higher for boys than girls (p < 0.05; ES = 0.8
to 0.5). Moreover, Acctotal and Dectotal were higher in S3 + 1 for boys compared to girls
(p < 0.05; ES = 0.7 to 1.0). Acc<1.5 was moderately higher during S4 in boys compared to
girls (p = 0.044; ES = 0.6 (0.1; 1.2)). Notably, boys had higher numbers of decelerations
during L5 compared to girls in Dec>2.3 (p = 0.021; ES = 0.6 (0.2; 1.1)). Furthermore, S3 + 1
and S4 formats had more decelerations for boys compared to girls (p < 0.05; ES = 0.8 to 1.2).
Conversely, in Dec1.5-2.3, girls had more decelerations in M4 than boys (p = 0.009; ES = 0.9
(1.5; 0.4)).
The girls had higher Time<120 in S3 + 1 and S4 compared to the boys (p < 0.05; ES = 0.7
to 1.9) (Table 1). In addition, Time>200 in S4 was moderately higher for girls compared to
boys (p = 0.034; ES = 0.7 (1.2; 0.1)). A detailed representation of the differences in activity
proﬁle, heart rate, subjective ratings, and technical involvement is reported in Figure 5.
Res. Public Health 2021, 18, 5663 
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Table 2. Differences in technical demands between game formats. Data are mean ± SD. 
Variables 
Sex 
S3 + 1 
S4 
M4 
M5 
L5 
ots (counts) 
Boys 
7.0 ± 4.1 
6.4 ± 3.9 
4.9 ± 3.3 
3.5 ± 2.6 a,b 
3.2 ± 2.1 a,b 
 
Girls 
7.4 ± 3.5 
6.0 ± 5.2 
4.7 ± 2.8 
3.8 ± 3.0 a 
2.8 ± 2.0 a 
als (counts) 
Boys 
2.5 ± 2.4 
2.2 ± 2.1 
2.0 ± 2.0 
1.1 ± 1.3 
1.1 ± 1.0 
 
Girls 
3.9 ± 2.9 
2.4 ± 1.5 
1.6 ± 1.4 a 
0.7 ± 0.9 b 
1.0 ± 1.3 a 
ful shots (counts) 
Boys 
35.2 ± 29.2 
34.7 ± 23.9 
38.0 ± 30.1 
29.2 ± 32.0 
32.2 ± 28.9 
 
Girls 
53.7 ± 23.9 
47.4 ± 41.3 
35.3 ± 25.8 
15.4 ± 22.5 a,b 
31.0 ± 38.9 
uels (counts) 
Boys 
1.1 ± 1.2 
0.7 ± 1.3 
0.7 ± 1.1 
0.5 ± 0.9 
0.4 ± 0.6 
 
Girls 
1.7 ± 2.8 
1.6 ± 2.1 
1.2 ± 1.7 
0.6 ± 1.0 
0.6 ± 1.2 
e mean ± SD. S3 + 1: small size, 3 vs. 3 + offensive goalkeeper; S4: small size, 4 vs. 4; M4: medium size, 4 vs. 4; M5: 
m size, 5 vs. 5; L5: large size, 5 vs. 5. a denotes significant differences compared to S3 + 1; b to S4. 
3.4. Gender 
The boys covered more TD in S3 + 1, S4, M5, and L5 compared to the girls (p < 0.05; 
ES = 0.8 to 0.9). Furthermore, the boys reached higher Vpeak during S4 and M5 compared 
to the girls (p < 0.05; ES = 0.7 to 0.9). Moderate higher sprints were observed in the M4 
format for boys compared to girls (p = 0.020; ES = 0.7 [0.2; 1.3]). Notably, the jog distance 
was higher for boys during S3 + 1, S4, M4, M5, and L5 compared to girls (p < 0.05; ES = 0.6 
to 1.2). In addition, sprinting in M4 and L5 was higher for boys than girls (p < 0.05; ES = 
0.8 to 0.5). Moreover, Acctotal and Dectotal were higher in S3 + 1 for boys compared to girls 
(p < 0.05; ES = 0.7 to 1.0). Acc<1.5 was moderately higher during S4 in boys compared to 
girls (p = 0.044; ES = 0.6 (0.1; 1.2)). Notably, boys had higher numbers of decelerations 
during L5 compared to girls in Dec>2.3 (p = 0.021; ES = 0.6 (0.2; 1.1)). Furthermore, S3 + 1 
and S4 formats had more decelerations for boys compared to girls (p < 0.05; ES = 0.8 to 
1.2). Conversely, in Dec1.5-2.3, girls had more decelerations in M4 than boys (p = 0.009; ES = 
0.9 (1.5; 0.4)). 
The girls had higher Time<120 in S3 + 1 and S4 compared to the boys (p < 0.05; ES = 0.7 
to 1.9) (Table 1). In addition, Time>200 in S4 was moderately higher for girls compared to 
boys (p = 0.034; ES = 0.7 (1.2; 0.1)). A detailed representation of the differences in activity 
profile, heart rate, subjective ratings, and technical involvement is reported in Figure 5.  
 
 
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Sprinting
HSR
MSR
Jog
St / W
Effect sizes
S3+1
S4
M4
M5
L5
Favours girls
Favours boys
B) 
Figure 5. Cont.
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ublic Health 2021, 18, 5663 
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Figure 5. Differences in (A) overall physical and physiological demands, (B) activity profile, (C) 
accelerations and decelerations, (D) heart rate, and (E) technical demands between boys and girls 
during different U9 handball games. The forest plots are effect sizes (90% CI). S3 + 1: small size, 3 v 
3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5: medium size, 5 v 5; L5: 
large size, 5 v 5. St/W: standing/walking; MSR: moderate-speed running; HSR: high-speed run-
ning. 
4. Discussion 
This study provides the first detailed analysis of movement patterns and heart rates 
in U9 team handball for boys and girls, showing that the exercise intensity, heart rates, 
and technical involvement are high during small, medium, and large-sized games in all 
investigated formats. When comparing game formats, we observed higher distances cov-
ered and more sprints with L5 but a lower number of accelerations and decelerations com-
pared to all the other formats. Notably, heart rates were similar between game formats. 
Irrespective of game format, boys covered 977–1320 m and girls covered 846–1124 m. For 
boys and girls, remarkably in the L5 format, TD, Vpeak, sprints, HSR, and sprinting were 
higher, whereas St/W, JOG, Acctotal, Dectotal, Acc<1.5, Acc1.5–2.3, Acc>1.5, Dec<1.5, Dec1.5–2.3, and 
Dec>1.5 were lower than other formats and, on many occasions, significantly different. This 
may be because there is more room for sprinting and high-intensity running on larger 
pitches, which is supported by the greater distance covered with high-intensity running 
and higher Vpeak during games on larger pitch sizes (40 × 20 m) compared with small 
pitches (20 × 13 m) in adult football players [25]. Interestingly, no differences were found 
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Dec ≤ -2.3 m⋅s-2
Dec -2.2 – -1.5 m⋅s-2
Dec ≥ 1.4 m⋅s-2
Acc ≥ 2.3 m⋅s-2
Acc 1.5 – 2.9 m⋅s-2
Acc ≤ 1.4 m⋅s-2
Effect sizes
S3+1
S4
M4
M5
L5
Favours girls
Favours boys
C) 
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Time >200 bpm
Time 180 – 200 bpm
Time160 – 180 bpm
Time 120 – 160 bpm
Time < 120 bpm
Effect sizes
S3+1
S4
M4
M5
L5
Favours girls
Favours boys
D) 
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Duels
Succesful shots
Goals
Total shots
Effect sizes
S3+1
S4
M4
M5
L5
Favours girls
Favours boys
E) 
Figure 5. Differences in (A) overall physical and physiological demands, (B) activity proﬁle, (C) accelerations and decelera-
tions, (D) heart rate, and (E) technical demands between boys and girls during different U9 handball games. The forest plots
are effect sizes (90% CI). S3 + 1: small size, 3 v 3 + offensive goalkeeper; S4: small size, 4 v 4; M4: medium size, 4 v 4; M5:
medium size, 5 v 5; L5: large size, 5 v 5. St/W: standing/walking; MSR: moderate-speed running; HSR: high-speed running.
4. Discussion
This study provides the ﬁrst detailed analysis of movement patterns and heart rates
in U9 team handball for boys and girls, showing that the exercise intensity, heart rates,
and technical involvement are high during small, medium, and large-sized games in
all investigated formats. When comparing game formats, we observed higher distances
covered and more sprints with L5 but a lower number of accelerations and decelerations
compared to all the other formats. Notably, heart rates were similar between game formats.
Irrespective of game format, boys covered 977–1320 m and girls covered 846–1124 m. For
boys and girls, remarkably in the L5 format, TD, Vpeak, sprints, HSR, and sprinting were
higher, whereas St/W, JOG, Acctotal, Dectotal, Acc<1.5, Acc1.5–2.3, Acc>1.5, Dec<1.5, Dec1.5–2.3,
and Dec>1.5 were lower than other formats and, on many occasions, signiﬁcantly different.
This may be because there is more room for sprinting and high-intensity running on larger
pitches, which is supported by the greater distance covered with high-intensity running
and higher Vpeak during games on larger pitch sizes (40 × 20 m) compared with small
pitches (20 × 13 m) in adult football players [25]. Interestingly, no differences were found
Int. J. Environ. Res. Public Health 2021, 18, 5663
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between S4 and M4 in any variables (physical, physiological, subjective perception, and
technical). As we already reported, other team sports showed that manipulating the
player numbers and the pitch size can alter the exercise intensity (i.e., distance covered,
jogging and walking, heart rate, and tackling, dribbling, goal attempts, and passes) during
a game in different sports [8]. The forces generated while rapidly changing direction,
stopping, and landing, as well as during jumping and shooting, may confer excellent
osteogenic properties to team handball [26]. It is well known from cross-sectional studies
that participation in sports activities is associated with markedly higher muscle mass and
bone mineralization, as well as better coordination and postural balance [27,28], and a
longitudinal intervention study with 8–10-year-old children has shown that participation
in school-based small-sized ball games enhances the same parameters [29]. The mean
HR was high for boys and girls, at 166–176 bpm and 165–175 bpm, respectively, in all
game formats. A high HR during sports and, speciﬁcally, team handball match-play,
irrespective of game format and gender, is important for the health proﬁle of children [30].
Aerobic high-intensity training (>90% maximum HR) has been shown to be superior to
moderate continuous training in improving cardiorespiratory ﬁtness [31,32], which has
been identiﬁed as a strong independent predictor of the risk of cardiovascular diseases and
mortality [33]. Sports participation is an effective way to improve aerobic and anaerobic
ﬁtness, especially participation in high-intensity ball games [34]. For the Time180–200 and
Time>200 in S3 + 1 format, young girl and boy team handball players spent more time
above 180 bpm, which is not signiﬁcantly different but working at a high intensity for more
time could improve cardiorespiratory ﬁtness positively [35]. No differences occurred in
subjective perception between different game formats, in contrast with other studies [6,36]
that found that larger courts felt more physically demanding. In our study, we had more
goals and more shots in the small size pitch (S3 + 1, S4), as was also observed in a study by
Randers and colleagues [7], where smaller pitches created more technical actions and may
seem logical, as ball contacts are higher during a game with fewer players [37]. Interestingly,
no differences were found in 1 v 1 duels in all the formats, that the players may try to score
or shot faster in games with small size pitches. Involvement with many relevant activities
is important in terms of motivation for children [38], as it helps the players to continue as
active handball players. Maturation at this stage is still early, whereas it seems that the
physiological load of the game is higher for boys than for girls, with many differences
between them, as is supported by the work of Michalsik and colleagues [3] in the different
distance zones, except for the TD, which females covered more of. A possible explanation
is that boys have more self-conﬁdence and perceived self-competence, making the game
more demanding [39]. Only one signiﬁcant difference was observed in favor of the girls
in Dec1.5–2.3, which had more decelerations in the M4 format. However, for physical
loading between sexes, similar HR values were found, with only three comparisons, girls
spent more time below 120 bpm in S3 + 1 and S4 compared to boys for Time>200 in
S4. Additionally, no signiﬁcant differences were found for subjective perceptions or the
technical analysis. In conclusion, having both genders mixed in the same format and game
would possibly be very demanding for girls in terms of activity patterns at this age.
It is important to underline some limitations inherent to this study, Firstly, physical
and physiological demands were compared across game formats of various pitch sizes
and numbers of players, and thus, relative space per player was not constant. Secondly,
maximum HR, maximal aerobic speed, and maximal sprinting speed were not assessed.
The use of ﬁxed HR and speed zones does not reﬂect the actual individual capacity,
possibly resulting in under- or overestimating the real physical and physiological demands
of the game. Although the technical analysis was carried out by experienced handball
coaches, this analysis could be somewhat subjective. Thus, our technical analysis should
be interpreted with caution. Finally, for logistical reasons, we were unable to describe
the physical levels of the players. Future studies are warranted to use individualized HR
and speed zones to accurately quantify the physical and physiological demands of youth
Int. J. Environ. Res. Public Health 2021, 18, 5663
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team handball as well as physical evaluations of the players. In this context, the ﬁtness
component of max speed can be adopted in future studies as suggested by [40].
5. Conclusions
In summary, the HR and high-intensity distances are high in U9 team handball matches
irrespective of the game format. The present data provide insight into how different game
formats inﬂuence the physiological and the physical loading and evidence that various
types of match-plays can contribute signiﬁcantly to the improvement in the musculoskeletal
and cardiovascular ﬁtness of U9 boys because of high HRs and high-intensity running
distances, along with multiple accelerations and speciﬁc actions with considerable impact.
In all the game formats, physical loading seems similar but, interestingly, on the large pitch,
the physiological load was higher. Playing with fewer players on smaller pitches resulted
in minor changes to the physiological loading but elevated the technical involvement of
players, which favors the use of smaller formats to emphasize technical demands. Several
differences between girls and boys were found in U9 team handball players that should be
considered when planning games for boys and girls separately or for mixed-gender games.
The various game types could provide valuable information to coaches in the selection of
players or training guidance. We would recommend the use of games with fewer players
on smaller courts for U9 boys and girls since we believe that technical development is the
most important factor at this age.
Author Contributions: Conceptualization, G.E. and M.N.L.; methodology, M.B.R.; validation,
M.N.L., P.K., M.B.R. and G.E.; formal analysis, G.E.; investigation, G.E. and R.C.E.; resources, P.K.,
M.B.R. and M.N.L.; data curation, G.E. and V.R.; writing—original draft preparation, G.E.; writing—
review and editing, M.N.L., P.K., M.B.R., V.R. and G.E.; visualization, G.E. and V.R.; supervision,
M.N.L., P.K. and M.B.R.; project administration, G.E.; funding acquisition, M.N.L., P.K. and M.B.R.
All authors have read and agreed to the published version of the manuscript.
Funding: This research was funded by the Danish Handball Federation, grant number 10-154-15655.
Institutional Review Board Statement: Ethical review and approval were waived for this study, due
to these types of academic research projects, formal ethical approval is not required by law.
Informed Consent Statement: Patient consent was waived, due to these types of academic research
projects, patient consent is not required by law but only oral consent.
Conﬂicts of Interest: The authors declare no conﬂict of interest.
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Exercise Intensity and Technical Involvement in U9 Team Handball: Effect of Game Format.
Ermidis, Georgios,Ellegard, Rasmus C,Rago, Vincenzo,Randers, Morten B,Krustrup, Peter,Larsen, Malte N