Task design in football and training load
“These players are not fit. They need to run more during training.” How many times have we heard this after witnessing a soccer team lose a game? Although soccer is very physically demanding, the idea that running more solves all problems is far from the truth. Football primarily depends on technical and tactical skills, with decision-making playing a crucial role.
I believe that the primary goal of training is to enhance the team’s game model, which encompasses tactical, technical, and physical aspects that are inseparable due to the nature of the game. This involves developing collective behaviors that enable the team to surpass the opposition when attacking and withstand them when defending.
How do different variables in task design impact the internal and external training load?
Pitch size and number of players are the variables that have the most significant impact on the physical, physiological, and technical-tactical demands (Castellano & Casamichana, 2019).
Castellano and Casamichana (2019) propose a model that focuses on the primary actions within the game based on the interaction between players and pitch size. They introduce the concept of relative area per player (RAPP), calculated as the pitch size (in m2) divided by the number of players. The model is divided into three conditional qualities:
Strength: Tasks involving a high number of accelerations, decelerations, and changes of direction with a small number of players and a small RAPP.
Endurance: High-intensity tasks at a cardiovascular level. A high RAPP and a small number of players are used.
Speed: Tasks focused on high-speed running actions. This requires sufficient space and time. Therefore, these exercises will involve a high number of players and a high RAPP.
Tabel 1. Different game formats according to space and number of players (Castellano & Casamichana, 2019)
Depending on the session’s objective and the task, these two variables can be combined, as shown in Table 1, to have a more significant impact on certain specific qualities. Castellano and Casamichana (2019) not only recommend using SSG, but also Medium and Large-Sided Games. In smaller spaces, the number of accelerations and decelerations will increase, while the distance covered at high speed will decrease (Clemente et al., 2022). As the RAPP increases, the players’ physical and physiological load and perceived effort (RPE) also increase (Casamichana & Castellano, 2010). Depending on our objective, there are also several variables that we can modify and will influence the actions during the game.
Game format
Coaches often use situations of numerical advantage or disadvantage to achieve specific tactical goals. In 2010, Hill-Haas et al. studied the impact of using teams with an equal number of players (3 vs 3 and 5 vs 5) compared to teams with an unequal number of players (3 vs 4 and 5 vs 6). They found that the total distance covered by the equal teams was greater than that of the teams with the higher number of players. The players in the outnumbered teams reported higher RPE compared to the teams with more players.
Inclusion of floaters
Hill-Haas et al. (2010) found that in smaller spaces, the floaters covered a greater total distance, whereas in larger spaces, they completed a greater number of high-intensity runs (>18 km/h).
Asian et al. (2022) conducted a study to investigate the correlation between the position of the floaters (Figure 1) and the internal and external training load in a 4 vs 4 + 2 task among semi-professional soccer players. The study found that regular players experienced higher internal and external loads in all formats. Additionally, floaters in the inside and outside positions had higher internal and external loads compared to those in the zone and square positions, with the inside position being the most demanding. The authors concluded that adding floaters to the task could be an effective strategy for reducing the training load on these players, and it may be used as an active recovery or with players in the process of returning to play.
Image 1. SSG Design by Asian et al. (2022)
In match simulation tasks, the inclusion of floaters can mean a greater reduction in intensity than in tasks with the objective of maintaining possession of the ball (Lacome, et al., 2017).
Inclusion of goalkeepers
It’s quite surprising that there’s very little research evaluating the impact of including goalkeepers on the internal and external training load in soccer.
The only study directly investigating this found that including goalkeepers reduces the intensity of the physiological responses and the distances covered at high intensity. The authors suggest that this might be because including goalkeepers leads to more passes and shots on goal, which can slow down the pace of the task and increase the time the ball is out of play (Koklu, et al., 2015).
Training regime
Casamichana et al. (2013) studied the difference between interval and continuous training regimes. They found that both formats are effective for achieving high intensity in the task. However, the total distance covered was greater in the intermittent game formats, as were the distances covered at speeds greater than 13km/h. On the other hand, RPE and maximum heart rate (HR) may be higher in the continuous format (Hill-Haas et al., 2011).
If the primary goal of training is to elicit greater cardiovascular responses, longer game formats should be utilized, whereas, if the primary goal is to promote high-intensity actions, game formats should be shorter (Casamichana et al., 2014).
Rest duration
In a recent study by de Dios et al. (2024), it was found that short rests (1-2 minutes) increased the RPE of soccer players, while long rests (4 minutes) led to an increase in the number of accelerations and decelerations. Another study by Branquinho et al. (2021) observed that long rests increased actions at maximum speed, while short rests tended to promote greater physical demands, both internal and external.
Short rest periods usually result in higher internal demands and a higher RPE, whereas longer rest periods tend to favor an increase in high-intensity and speed actions. However, the effect of rest on the training load is largely determined by the duration of each repetition and the design of the task. The use of the work:rest ratio can be helpful in quantifying this variable.
Rules modification
The modification of certain rules during tasks is a common practice aimed at influencing team behavior. Offside is a frequently modified rule, but it appears to have no effect on the HR of footballers during SSG (Custódio, et al., 2022).
Halouani et al. (2017) investigated the effect of different ways of scoring goals in SSG on young football players. The study’s findings indicated that using an area at the end of each half of the field where players had to control and stop the ball in order to score resulted in greater physiological responses (HR, RPE, and lactate levels) compared to using small goals. Including the rule that all players must be in the opponent’s half for the goal to count has been shown to increase maximum HR and blood lactate levels (Hill-Haas, et al., 2010).
Number of ball touches
Casamichana et al. (2014) discussed the results of several studies showing an increase in intensity in several physical parameters when the allowed number of touches was reduced. However, their study yielded different results. By allowing only two touches in a possession game (12-min; 6 vs. 6; RAPP of 245 m2), in the first 6 minutes, it was observed that players spent more time at an intensity level below 80% of their maximum HR. In the second 6 minutes of the game, there was a significant decline in running performance in the group without a limit on ball touches, while in the group with a limit, an increase was observed in the amount of time that players spent in the high-intensity zone (>90% of their maximum HR). Fatigue and the technical-tactical skills of the players can greatly influence this variable.
Type of marking
Research has shown that man-marking leads to increased distance covered at moderate and high intensity, as well as a higher number of high-intensity accelerations. However, it does not appear to significantly affect the physiological demands (Casamichana, et al., 2015).