Pay attention! The influence of coach-, content-, and player-related factors on focus of attention statements during tennis training

ABSTRACT

It is well established that adopting an external focus of attention (EF) enhances motor learning when contrasted to an internal focus (IF) or a neutral condition. Despite consistent evidence for this performance-enhancing effect of an EF, recent studies show that coaches predominantly induce an IF in the communication with athletes. It remains, however, unknown whether and to what degree coach-, content- or player-related factors have an impact on the focus of attention during youth tennis training. Therefore, we recorded all statements from 10 tennis coaches during six training sessions with a total of 87 youth athletes aged 18 years or younger. All statements were categorized according to the focus they induced (IF, EF, neutral, best place to hit the ball, mix, no focus) and the form of communication (instruction, feedback). Of the relevant statements (n = 3049), 45.1% promoted an EF, whereas 33.1% induced an IF. Evaluation of coaches-, player- and content-specific features (education, age of coach/player, training content, skill level) showed that more statements with an IF were given when training beginners. The data also show more statements with an EF for instructions (59.0%) compared to feedback (43.0%). Our results contrast with other sports where instructions with an IF predominate. Thus, instrumented sports with external targets (e.g. tennis) might be better suited for inducing an EF. The data also show that coaches are more likely to use IF when communicating with beginners. Consequently, an EF should not be induced in every possible situation, even if this is often communicated so far.

Highlights

• This study shows for the first time that statements that induce an external focus of attention predominate in tennis. This result contrasts with results from other sports and suggests that racquet sports may be better suited for inducing an external attentional focus.

• This study shows that coaches adapt their communication to the performance level of their athletes. The use of an external focus of attentions predominates when working with tennis players. However, the likelihood of inducing an EF is even higher when working with skilled tennis players when compared to beginners.

• The way of communication (feedback vs. instruction) influences how coaches phrase their statements to athletes. The analysis revealed that coaches use more statements with an external focus of attentions for instructions compared to feedback.

KEYWORDS:

• Youth
• coaching
• motor control
• team sport
• testing

Introduction

In the last decades, much research effort has been devoted to investigating which variables affect the performance and learning of skills (for review: Wulf, Shea, & Lewthwaite, 2010). One of these variables is the so-called focus of attention. Wulf, Hoss, and Prinz, (1998) were the first who examined the effects of different types of instructions on skill learning. The authors compared the effects of different instructions that were either related to the movements of the body (internal focus) or to the effects of these movements on the environment (external focus). Their results showed a more effective learning with an external focus of attention (EF) when compared to an internal focus of attention (IF). The findings of this initial study were often replicated with research almost consistently showing enhanced motor performance and learning when inducing an EF by instructions or feedback statements (for reviews: Lohse, Wulf, & Lewthwaite, 2012; Wulf, 2013; Wulf & Prinz, 2001).

The EF-related performance enhancements are often explained using the “constrained action hypothesis” (McNevin, Shea, & Wulf, 2003; Wulf, McNevin, & Shea, 2001). According to this hypothesis, an IF is a more conscious type of control that interferes with automatic control processes and thereby constrains the motor system. More precisely, the hypothesis stipulates that an IF represents an active intervention in (automatic) control processes and therefore degrades a coordinated motor output. In contrast, an EF seems to promote more automatic modes of control and therefore results in an enhanced performance (Wulf, 2013). The idea of the constrained action hypothesis was supported by studies showing an improved neuromuscular strategy (Lohse, Sherwood, & Healy, 2011; Vance, Wulf, Tollner, McNevin, & Mercer, 2004; Walchli, Ruffieux, Bourquin, Keller, & Taube, 2016; Wulf, Dufek, et al., 2010) but also a more efficient brain activation (Kuhn, Keller, Egger, & Taube, 2021; Kuhn, Keller, Lauber, & Taube, 2018; Kuhn, Keller, Ruffieux, & Taube, 2017a; Kuhn, Keller, Ruffieux, & Taube, 2017b) with an EF.

Although the performance-enhancing effects of EF instructions have been amply demonstrated, there is only little research on the question whether these findings have made their way from scientific papers into practical implementation. Evidence from track and field (Porter, Wu, & Partridge, 2010) shows that statements with an IF prevail in the communication of coaches and athletes, regardless of the scientific evidence supporting the use of an EF. However, activities such as running – a cyclic activity with hardly any external reference points – gives the coaches only very little opportunities to provide instructions pertaining to the movement effects. The absence of reference points could explain why almost 85% of the instructions induced an IF in track and field. One might therefore argue that motor tasks with a clear environmental goal enhance the probability for giving EF instructions. In line with this argument, a higher percentage of statements with an EF (31%) were reported for baseball pitching (van der Graaff, Hoozemans, Pasteuning, Veeger, & Beek, 2018). Thus, disciplines with external targets and environmental goals might be better suited to induce an EF. To support this assumption with empirical data, the relative frequencies of statements inducing a particular attentional focus were examined for tennis in the present study.

A second objective was to examine if coach-, content-, and player-related factors have an influence on the relative frequencies of attentional focus statements. The proficiency level is important to consider since there is evidence showing that focus statements can have different effects on low-skilled and high-skilled players. For example, focusing attention on a movement effect that is farther away from the body (distal EF) generally leads to more efficient motor performance than focusing on a movement effect that is in closer proximity to the body (proximal EF) (Singh & Wulf, 2020; Wulf, 2013). However, the optimal distance of the EF depends on the level of expertise with low-skilled participants benefiting most from a proximal EF, whereas a distal EF is more beneficial for highly-skilled athletes (Singh & Wulf, 2020). Additionally, there is also contrasting evidence for a performance-enhancing effect with an EF in elite athletes. While some studies have shown enhanced performances with an EF in highly-trained athletes (Ille, Selin, Do, & Thon, 2013; Wulf & Su, 2007), other studies could not replicate these findings (Keller, Kuhn, Luthy, & Taube, 2018; Winkelman, Clark, & Ryan, 2017; Wulf, 2008). Thus, the expertise level of the athletes could have an impact on which focus is ideally applied. The main purpose of this study was therefore to examine how often tennis coaches – through their instructions and feedback – invoke an IF vs. EF during tennis training. Moreover, we examined whether factors related to the coach (age and formal education), the thematical content of the session (stroke movements) or the players (proficiency and age) have an influence on the way of communication.

Methods

Participants and procedures

The study was designed as a cross-sectional, observational study. In total, 10 tennis coaches (1 female, 44.5 ± 8.7 years) were recruited by means of written inquiries in the German-speaking part of Switzerland. In total, coaches from six different training centres were recruited to participate, with two coaches working at the national training centre of Swiss Tennis. Six of the participating coaches were classified as having high formal qualifications (Swiss Olympic Certificate, Trainer-A Tennis). Coaches were eligible if they were willing to participate in the study with at least three different training groups of youth athletes (≤18 years). A total number of 34 training groups (with 1–6 players per group) were involved in the study. These groups were composed of 87 players. Sixteen players were playing in the U10 category, 35 players in the U14 category, and 36 players in the U18 category. Moreover, 46 players were categorized as beginners (classified R8-R9 in the Swiss Tennis classification system), 29 players as advanced (classified R5-R7), and 12 players as skilled (classified R4 or better).

The data assessment took place between November 2019 and June 2020 and was captured in a naturalistic setting by the same researcher (JS). The researcher took a passive role who solely documented the content of the trainings. Each coach was visited in three trainings and was asked to train two of three different thematical contents (forehand topspin vs. volley vs. serve) in one training. Each content was classified as a separate session for the data analysis. This means that statements of coaches were recorded in 6 sessions (3 trainings with 2 contents). In total, 60 training sessions were recorded (6 sessions per coach). Each session contained a basic training sequence, which had to be (at least) slightly modified once during the session. No requirements were set regarding the specific tasks during the training, the duration or the selection of specific goals. Typically, the trainings also contained other contents such as warm-ups or different forms of games, but these contents were not considered in the data analysis. The coaches could decide freely whether they wanted to use assistive devices to facilitate the organization of the sessions (e.g. cones, floor markings, etc.).

In each session, the entire communication between the coach and the athletes was recorded. Prior to the beginning of the training, athletes received general information about the study without unveiling the more concrete purposes of the investigation. Importantly, it was explained to the athletes that only the verbal statements of the coach would be analysed.

In Switzerland, ethical requirements for studies are defined in the Human Research Act (HFG, Article 2). With a focus on motor learning, no formal ethical approval was required for the present study, which was also confirmed by the ethics committee. All procedures were carried out in line with the Declaration of Helsinki and Good Clinical Practice. Prior to the data assessment, the coaches were informed about the general purpose of this study (better understanding the communication between coaches and athletes), without explaining specific goals or the variables of interest. All coaches provided informed written consent prior to data assessment.

Materials and measures

Each coach was equipped with a portable microphone connected to an iPhone 7. The recordings were done using a suitable app. A back-up recording was done with another iPhone that was placed on the tennis court. The voice recorders were active during the entire training session.

Data analysis

MaxQDA 2020 was used for the transcription of all verbal statements made by the coaches. In a first step, all statements that were related to a certain movement or movement description were identified as relevant statements. In a second step, these statements were then classified as instruction or feedback statements using the following definition (Johnson, Burridge, & Demain, 2013): Instructions contain information about a desired action or its execution and are typically given before an action is initiated. A feedback statement is based on previously made observations and tries to influence further attempts. In a third step, we examined whether or not a specific attentional focus was invoked. Finally, statements that contained an attentional focus were classified into one of five categories: internal, external, neutral, mixed, and best place to hit the ball (examples are provided in the supplementary material). Statements were defined as invoking an IF if they draw a person’s attention to movements of the body or specific body parts. Statements that draw a person’s attention to the effects of movements or certain features in the environment or that reflect pictorial descriptions of a movement (metaphors) were defined as invoking an EF. In contrast to van der Graaf et al. (2018) who used a similar study design, we used five instead of three attentional focus categories (internal, external, other) to provide a more complete and fine-grained picture of the communication that took place during the tennis sessions. For two reasons, taking into account the category labelled “best place to hit the ball” was considered essential. First, hitting the ball at the correct place should be considered as the key element in tennis since timing is essential. Second, the place where the ball is hit is always located outside of the player’s body, and thus always invokes an EF. Since players also do not focus on a movement effect when statements about the “best place to hit the ball” are given, the introduction of a separate category seemed reasonable. In addition, no “internal attentional focus” counterpart exists for the “best place to hit the ball” category, so it was deemed necessary to consider this category separately to avoid a bias of the findings towards the EF. All statements were rated twice by the same researcher (JS). Of the 7713 statements, 7591 were rated identically in round 1 and round 2. In the remaining cases (n = 122) with diverging classifications, a further researcher (MG) was consulted and each statement was discussed until an agreement was reached.

The classifications of the statements were then transformed into a numerical data set using SPSS software (version 26, IBM Corporation, Armonk, USA). The following variables were used as categorical variables: coach (N1-10), coach qualification (higher, lower), thematical content (forehand topspin, volley, serve), players’ age (U10, U14, U18), and players proficiency (beginner, advanced, skilled). Because no standardization was achieved with regard to the duration of the training sessions, and because the coaches differed regarding the amount of absolute verbal statements, relative (rather than absolute) frequencies for each coach were used for the statistical model.

Descriptive statistics are presented as means (M), standard deviations (SD), 95% confidence interval and percentage values. Differences in the use of the five different categories (neutral vs. EF vs. IF vs. best place to hit the ball vs mixed) were tested via univariate analyses of variance (ANOVAs). Differences between attentional focus and coach-, content-, and player-related factors were examined via linear mixed models. Random intercepts were used for the coaches to account for inter-coach differences. Similarly, a linear mixed model was used to analyse differences between instructions and feedback with random intercepts for coaches. If significant differences were identified in the mixed linear models, pairwise comparisons (with Sidak corrections) were calculated to obtain more specific information about the nature of the differences. The level of significance was set at p < 0.05 across all analyses.

Results

Descriptive findings and general observations

During the recorded sessions, the coaches made a total of 7713 statements, with 39.5% (n = 3049 statements) invoking a specific attentional focus. In total, 45.1% of these statements invoked an EF, 33.1% an IF, 11.5% were neutral, 5.2% were mixed, and 5.1% concerned the best place to hit the ball. As shown by the confidence intervals (see Table 1), a considerable variation was observed within each category. Nevertheless, the fact that no overlap was found in the confidence intervals highlights that statements with an EF were used more often than statements with an IF.

Table 1. Relative frequencies of coaching instructions and feedback, separately for different attentional focus categories. (Notes: M and SD reflect relative frequencies of statements within each coach).

	Instructions			Feedback			Total
	M	SD	95% C.I.	M	SD	95% C.I.	M	SD	95% C.I.
Neutral	8.2	14.4	5.0–12.2	12.0	12.4	8.8–15.1	11.5	11.9	8.4–14.5
Internal	23.3	22.5	17.8–29.4	34.9	21.4	29.8–40.7	33.1	190.8	28.4–38.5
External	59.0	28.3	51.7–66.2	43.0	20.4	37.4–47.8	45.1	20.2	39.6–50.0
Best place to hit the ball	1.9	6.2	0.6–3.6	5.6	7.9	3.9–8.1	5.1	7.2	3.6–7.3
Mixed	7.6	11.2	5.0–10.7	4.5	4.7	3.5–5.8	5.2	5.2	4.2–6.7

In general, statements with an EF predominated among the coaches with eight of ten coaches showing the highest relative frequencies for EF statements. However, substantial differences occurred in the categories between the coaches (see details in supplementary material). Significant between-coach differences were found for the categories EF (F(9,50) = 2.73, p < 0.01, η²= 0.33) and IF (F(9,50) = 3.55, p < 0.001, η²= 0.39). By contrast, no significant differences were observed for the categories “neutral” (F(9,50) = 1.50, p = 0.17, η²= 0.21), “mixed” (F(9,50) = 0.58, p = 0.81, η²= 0.09) and “best place to hit the ball” (F(9,50) = 2.06, p = 0.06, η²= 0.27). In three coaches (Nr. 1, 5, 8), the mean difference between the IF vs. EF category was lower than 10%, in three coaches (Nr. 2, 3, 6) lower than 20%, and in four coaches (Nr. 4, 7, 9, 10) higher than 30%. The standard deviations highlight that the coaches not only differed from each other; rather, the use of the different attentional focus categories also varied in the six recorded training sessions within the same coach. The highest variation was found in the EF, IF and “neutral” categories.

Instruction versus feedback

In the present study, coaches gave more feedback (total statements: n = 6787, 88.0%; statements with attentional focus: n = 2553, 83.7%) than instructions (total statements: n = 926, 12.0%; statements with attentional focus: n = 496, 16.3%).

As shown in Table 1, if coaches provided instructions, they most often used an EF (M = 59.0%), followed by IF (M = 23.3%), “neutral” (M = 8.2%), “mixed” (M = 7.6%) and “best place to hit the ball” (M = 1.9%) categories. By contrast, the difference between the relative frequencies of the various categories was smaller if coaches provided feedback. Again, most of the feedback statements invoked an EF (M = 43.0%), followed by statements that invoked an IF (M = 34.9%). The results of the mixed linear model analyses are displayed in Table 2, showing significant differences for the IF, EF and “best place to hit the ball” categories (all p < 0.01).

Table 2. Results of data analyses examining the relationship between instruction/feedback and the different attentional focus categories.

	ΔM	df	t	p	95% C.I.
Neutral	3.68	8.13	1.92	0.09	−0.73; 8.08
Internal	11.70	9.09	3.93	<0.001	3.98; 18.42
External	−16.25	9.06	−4.29	<0.001	−24.81; −7.69
Best place to hit the ball	3.92	9.13	3.35	<0.01	1.28; 6.56
Mixed	−2.99	8.32	−1.97	0.08	−6.46; 0.49

Coach-, content-, and player-related factors

Table 3 provides an overview of the different attentional focus categories, separately for the coach-, content- and player-related factors. Independently of their level of qualification, coaches used more statements that invoked an EF (higher qualification: M = 49.0%; lower qualification: M = 39.3%) than an IF (higher qualification: M = 31.1%; lower qualification: M = 36.2%). Nevertheless, the difference in the relative frequencies was higher among coaches with a higher formal qualification. Statements relating to the best place to hit the ball were more often used by less qualified coaches (M = 8.4%) compared to their more qualified counterparts (M = 2.9%). The results confirmed that the coaches’ formal qualification was significantly associated with the frequency of statements related to the best place to hit the ball (p < 0.05). No significant differences were found for the other categories (see additional results provided in supplementary material).

Table 3. Descriptive statistics of the various types of attentional focus, separately for coach-, content-, and player-related factors. (Notes: M and SD reflect relative frequencies of statements within each coach).

		Neutral			Internal			External			Best place to hit the ball			Mixed
		M	SD	95% C.I.	M	SD	95% C.I.	M	SD	95% C.I.	M	SD	95% C.I.	M	SD	95% C.I.
Formal qualification of the coach	Higher	11.4	11.6	7.5–15.4	31.1	23.1	23.3–38.9	49.0	21.7	41.7–56.4	2.9	4.6	1.3–4.5	5.5	6.1	3.5–7.6
	Lower	11.5	12.6	6.2–16.8	36.2	13.4	30.5–41.8	39.3	16.3	32.4–46.2	8.4	9.1	4.5	12.2	4.7	3.3–6.0
Age of the coach	<40 years	14.2	13.9	7.2–21.1	26.4	17.4	17.7–35.0	52.8	18.2	43.7–61.8	2.1	3.8	0.3–4.0	4.6	5.7	1.8–7.4
	40–49 years	10.7	7.1	7.2–14.2	36.4	15.1	28.9–43.9	39.6	18.8	30.3–48.9	7.3	7.2	3.7–10.9	6.0	4.5	3.8–8.2
	≥50 years	10.0	13.2	4.4–15.6	35.8	23.7	25.8–45.8	43.6	21.6	34.5–52.7	5.6	8.6	2.0–92	5.0	5.4	2.8–7.3
Thematical content of the lesson	Forehand Topspin	13.7	9.2	9.4–18.0	23.4	17.1	15.4–31.4	53.1	21.2	43.2–63.0	5.5	5.6	2.8–8.1	4.3	5.0	2.0–6.7
	Volley	12.6	12.8	6.7–18.6	38.6	18.7	29.8–47.3	36.6	18.5	27.9–45.2	6.6	9.5	2.2–11.1	5.7	5.3	3.2–8.1
	Service	8.0	13.1	1.9–14.2	37.5	20.6	27.9–47.1	45.7	18.1	37.3–54.2	3.2	5.7	0.5–5.8	5.6	5.3	3.1–8.1
Age of the players	U10	11.8	11.5	4.5–19.1	43.1	25.1	27.2–59.1	36.1	21.6	22.4–49.8	3.0	4.6	0.1–6.0	5.9	4.8	2.9–8.9
	U14	12.4	12.0	7.7–17.1	33.3	16.4	26.9–39.8	43.9	17.6	36.9–50.9	6.1	8.8	2.7–9.6	4.3	3.8	2.8–5.8
	U18	10.1	12.4	4.4–15.7	27.2	19.1	18.5–35.9	51.9	21.0	42.3–61.5	4.9	6.1	2.1–7.7	6.0	6.7	2.9–9.0
Proficiency of the players	Beginners	15.0	14.3	9.3–20.7	36.1	17.8	29.0–43.1	39.8	20.2	31.8–47.8	4.9	8.0	1.7–8.1	4.3	3.8	2.8–5.7
	Advanced	11.7	10.1	6.7–16.7	37.2	22.9	25.8–48.5	40.4	18.8	31.0–49.7	5.2	7.3	1.6–8.9	5.6	5.8	2.7–8.4
	Skilled	4.8	4.4	2.4–7.3	23.1	16.8	13.8–32.4	60.5	13.8	52.9–68.2	5.2	6.0	1.9–8.5	6.4	6.5	2.8–10.0
Total		11.5	11.9	8.4–14.5	33.1	19.8	28.4–38.5	45.1	20.2	39.6–50.0	9.1	7.2	3.6–7.3	5.2	5.2	4.2–6.7

Table 3 further shows that no clear pattern emerged with regard to the age of the coaches. Accordingly, no significant differences were identified.

With regard to the thematic content, the relative frequency of statements with an IF was lower for forehand topspin (M = 23.4%) compared to volley (M = 38.6%) and serve practice (M = 37.5%). By contrast, the relative frequency of statements with an EF was highest during forehand topspin practice (M = 53.1%), followed by serve (M = 45.7%) and volley practice (M = 36.6%). During forehand topspin and serve practice, coaches used more statements that invoked an EF. By contrast, during volley practice, the IF slightly prevailed (see Table 3). The statistical analyses point towards a significant association for both the IF and EF category (see supplementary material). Pairwise comparisons showed that for the IF category, significant differences existed for forehand vs. volley (p < 0.01) and forehand vs. serve (p < 0.05), whereas for the EF category a significant difference was found for forehand vs. volley (p < 0.01).

With regard to the age of the players, no significant associations were found. Descriptively, EF invoking statements seemed to slightly increase with players’ age (U10: M = 36.1%, U14: M = 43.9%, U18: M = 51.9%), whereas an inverse pattern existed for statements that invoked an IF (U10: M = 43.1%, U14: M = 33.3%, U18: M = 27.2%). Thus, whereas the IF category prevailed among younger children, statements fostering an EF were dominant in the two older age groups (see Table 3 and supplementary material).

Coaches made more statements with an EF among proficient players as compared to beginners and advanced players. By contrast, neutral or IF statements were less frequently observed if coaches interacted with skilled players (Table 3). The analysis confirmed these descriptive findings; however, significant associations were only found for the EF (p < 0.05) and neutral (p < 0.05) categories, and only between beginners and skilled players (p < 0.05).

Discussion

The aim of this study was to empirically document to what extent verbal statements from coaches influence the focus of attention during tennis training. Data were collected during regular training sessions and therefore guaranteed a high validity. We also aimed for a high reliability by including several coaches and athletes resulting in a substantial number of statements used for data analysis (n = 3049).

Coaches prefer to induce an EF in tennis

In contrast to previous studies (Porter et al., 2010; van der Graaff et al., 2018), our data show that tennis coaches gave instructions and feedback more often with an EF (45.1%) than with an IF (33.1%) or a neutral condition (11.5%). We can only speculate about possible reasons for the differences between our and the previous studies (Porter et al., 2010; van der Graaff et al., 2018). As mentioned above, one likely explanation is that the discipline itself influences which focus of attention is preferentially induced. We believe that motor tasks with a clear environmental goal and external targets enhance the probability for giving EF instructions. In tennis, the ball (external target) must be played with a racket (external implement) over the net (environmental goal) into a certain landing zone (environmental goal). It is therefore reasonable to argue that the presence of these external goals and instruments made the tennis coaches more likely to apply statements with an EF. In line with this argument, we could show that the use of assistive devices indeed further increased the likelihood of inducing an EF when compared to situations when no assistive device was used (see Figure 1, supplementary material).

Figure 1. Percentage in focus categories by players’ proficiency.

We would also like to mention that some people might argue that the “best place to hit the ball” could also be categorized as an EF. We decided to classify all statements with respect to the “best place to hit the ball” as a separate category, because these statements are very often related to the timing (e.g. “you are too late”), but not to a movement effect (e.g. ball rotation or ball trajectory). Nevertheless, the place where the ball is hit is always located outside of the player’s body, and thus other authors might have classified all these statements as EF statements as well. Thus, depending on the chosen classification, the relative frequency of EF-statements might be even higher. To conclude, conditions in tennis appear to be more suitable to induce an EF compared with other sports (Porter et al., 2010; van der Graaff et al., 2018). Consequently, players are more likely to benefit from the advantages of an EF, which have also been documented for tennis (Tsetseli, Zetou, Vernadakis, & Mountaki, 2018).

Instruction versus feedback

This is the first study to disentangle whether there are any differences with respect to the focus of attention between instructions and feedback. A much larger number of feedback statements were found when compared to instructions. The reason for this difference lies in the organization of the training sessions. Coaches instructed their athletes on a certain technique and asked their athletes to practice this technique for several minutes. Since the instruction was only given once to all athletes, but the feedback was given frequently and to different players, the absolute number of feedback statements is much higher than for instructions.

When analyzing whether the relative frequencies of statements with a particular focus differed between instruction and feedback, the results showed differences for the categories IF, EF and “best place to hit the ball”. While 59% of the instructions induced an EF, the relative frequency for feedback statements was much smaller (43%). In comparison, the relative frequencies for IF and “best place to hit the ball” were higher for feedback when compared to instructions. One can therefore conclude that the way of communication (feedback vs. instruction) influences how coaches formulate their statements. Instructions and feedback differ in terms of when they are provided and which information they contain (Johnson et al., 2013). Since instructions in tennis do often contain an external goal or external target, the likelihood of inducing an EF might therefore be high. Unlike instructions, feedback is given after an exercise and conveys information based on previously made movement observations. Thus, feedback statements are very often movement-related and do more often induce an IF.

Coach-, content-, and player-related factors

We also assessed if coach-, content, or player-related factors influence how often a particular focus is induced.

Thematic content: It was argued in a recent publication that the motor task itself influences which attentional focus is preferred (van der Graaff et al., 2018). We therefore analysed whether the training content affects which attentional focus coaches prefer to use. The analyses showed clear differences between the strokes indicating that the analysis of one stroke does not represent a “pars pro toto”. Or in other words: scientists cannot generalize form the analysis of one specific stroke to the whole sports discipline. We therefore encourage scientists for future studies to better analyse the thematic content as this was not done in previous studies (e.g. Porter et al., 2010). One possible explanation why the highest relative frequencies with an EF were found for forehand topspin strokes could be the intended trajectory and the required ball rotation. Since these two aspects are of great importance for forehand topspin, coaches have made several statements about these two “movement effects” and thereby induced an EF. In addition, the coaches used considerably more metaphors – another way of inducing an EF – when instructing forehand topspin strokes when compared to volleys.

Coach-related factors: Neither the age nor the formal qualification of the coaches had a relevant influence on the results. The only difference was found in the “best place to hit the ball” category, with less qualified coaches using more of these statements than their more qualified counterparts. It is therefore reasonable to argue that the formal qualification had only a very minor influence on the focus of attention.

Player-related content: While we found no effects for the age of the players, differences were found for the player proficiency. The data showed that coaches made more statements with an EF among proficient players. A likely explanation is that novices need more details about movement kinematics to understand the general motor task (Oliveira et al., 2013). This assumption is further supported by evidence from “distance effect” studies showing that focus statements should be adapted to the actual skill level (Singh & Wulf, 2020). Thus, experienced learners might be better able to handle information from an instruction with an EF as they can associate instructions about the movement effect with that of the movement pattern. For example, only experienced players can chose an appropriate movement pattern to a statement such as “return with backspin”, whereas beginners need a movement description of how to achieve backspin. It seems therefore reasonable that tennis coaches provide more statements with an EF to skilled players.

Practical applications

The present study showed that the use of an EF generally predominates when working with skilled tennis players. However, the analysis also revealed that coaches adapt their communication to the performance level of their athletes, because novice players were found to have a higher relative frequency of IF statements than experienced players. Adapting the preferred focus of attention to the skill level is reasonable since previous studies have shown that the players’ proficiency has an influence on the effectiveness of different focus instructions (Singh & Wulf, 2020). We therefore encourage coaches to adapt their way of communication with respect to the proficiency level of their athletes.

Author contributions

Conceptualization: M. K., M. G. and J. S.; data analysis and statistics: J. S. and M. G.; investigation: J. S.; writing – original draft preparation: M. K. and M. G.; writing – review and editing: J. S.

Acknowledgements

This study was not supported by any external funding. The authors thank Swiss Tennis and all coaches and athletes for their cooperation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.