Background
Coaches have many responsibilities to promote the optimal development of their athletes and providing recommendations on sports nutrition certainly represent one important issue. Although family, friends, physicians, dietitians, the Internet, magazines and media represent important sources of information for high school athletes [
1‐
7], most of them obtain their information regarding sports nutrition and dietary supplements mainly from their coaches [
1‐
4,
6,
7]. Therefore, it is not surprising to see that many coaches provide general recommendations on sports nutrition to their athletes [
8‐
10].
One important related issue is that most coaches do not have specific or formal training in sports nutrition, and their knowledge is often inadequate to appropriately guide their athletes on nutrition topics [
8‐
12]. For instance, a study among French Canadian high school coaches showed that their nutrition knowledge is not optimal, yet, they reported providing advice on carbohydrates, proteins and hydration to their athletes [
10]. Although a coach’s role is not to be an expert in sports nutrition, their close and daily interactions with their athletes justify the need to possess nutrition knowledge and skills to adequately guide their young athletes on general sports nutrition. Moreover, some athletes have access to a sport dietitian, but this support is not as easily accessible, and especially not on a regular basis, to most young athletes compared to high performance athletes. Therefore, there is a need to develop nutrition interventions for coaches based on a current evaluation of their recommendations on sports nutrition. These interventions are also justified by the suboptimal eating habits of adolescent athletes to meet requirements of daily training and ensure growth and health [
13‐
18].
In order to develop an efficient intervention, it is essential to rely on a theoretical framework which allows a better understanding of the determinants of the targeted behaviour [
19], i.e., general sports nutrition recommendations provided by coaches. The theory of planned behaviour (TPB) has proven its efficacy in terms of predicting human social behaviours [
20] and was the theory most often used to assess the intentions and behaviours of healthcare professionals [
21]. To our knowledge, no study has yet assessed the psychosocial determinants of sports nutrition recommendations provided by French Canadian high school coaches. This will provide valuable information for the development of a novel intervention for coaches based on their own beliefs and aimed at improving their nutrition knowledge and the recommendations they provide to their athletes.
In this context, the aim of this study was to extend our understanding of French Canadian high school coaches’ nutritional practices by 1) assessing coaches’ intentions to provide three different recommendations on sports nutrition to their athletes (i.e., a higher consumption of foods rich in carbohydrates, foods rich in proteins and an increase in hydration) and 2) identifying the determinants underlying their intentions to provide these recommendations. Based on a previous study which showed that protein and hydration were the most provided sports nutrition recommendations [
10], it can be hypothesized that most coaches have the intention to provide these recommendations. At this time, it is premature to identify a hypothesis related to specific determinants of coaches’ intention to provide these recommendations since this has never been studied.
Discussion
This study aimed to assess high school coaches’ intention to provide three different sports nutrition recommendations to their athletes as well as to identify the determinants and their underlying beliefs of coaches’ intention towards these recommendations. Results showed that a higher number of coaches had the intention to recommend hydration than the consumption of foods rich in carbohydrates or rich in proteins to their athletes. Subjective norm and perceived behavioural control were identified as the main determinants of these intentions. To our knowledge, this study is the first to investigate coaches’ intention to provide recommendations on sports nutrition and their related determinants and beliefs. These findings are important since they represent theoretical foundations of future interventions aimed at facilitating proper general sports nutrition recommendations provided by high school coaches to their young athletes (e.g., [
29]).
In this sample of high school coaches, 46.3% reported having the intention to recommend a higher consumption of foods rich in carbohydrates to their athletes in the next 3 months, and the prevalence was not different depending on leanness or nonleanness sports. This result cannot be compared to other studies, since, to our knowledge, this study is the first to assess the intention regarding sports nutrition recommendations provided by coaches. It is, however, consistent with the prevalence of coaches (i.e., 47.6%) having reported that they had recommended the consumption of foods rich in carbohydrates during the last 12 months to their athletes (i.e., past behaviour) from the same sample of coaches [
10]. Considering that carbohydrate is the main source of energy for most exercise, it is important that athletes consumed this nutrient in a sufficient amount to support sport performance. As reported in the study of Lun et al. (2009), high performance Canadian athletes had daily carbohydrate intake of 5.1 ± 1.8 g/kg of body weight [
30], indicating that most athletes do not meet carbohydrate recommendations for moderate or high endurance exercise program (5–12 g/kg/d) according to guidelines [
31]. Similar results have been observed in adolescent athletes [
15,
16,
32,
33]. For example, 41% of club level male tennis players from Brazil (age 14–18 years) and 52% of junior elite Canadian female soccer athletes (age 15.7 ± 0.7 years) reported carbohydrate intake below the recommended values [
16,
33]. Insufficient carbohydrates during training have also been observed in skill (e.g., tennis) and team-sport adolescent athletes, as less than 30% consumed 30 to 60 g of carbohydrates per hour during training and competition [
13]. Considering that a high proportion of athletes do not consume enough carbohydrates daily, and that coaches represent an important source of nutrition information and influence, the result suggests that the prevalence of coaches having the intention to recommend a higher consumption of foods rich in carbohydrates should be higher.
The prevalence of coaches having the intention to recommend a higher consumption of foods rich in proteins to their athlete (i.e., 44.7%) is similar to the one related to carbohydrates, but lower than the number of coaches having reported they had provided this recommendation in the last 12 months (i.e., 97.5%) [
10]. In contrast to carbohydrate intakes, Lun et al. (2009) reported that Canadian athletes had a mean daily protein intake of 1.8 ± 0.6 g/kg of body weight [
30], meaning that most of them reach protein recommendations (i.e., 1.2–2.0 g/kg/d) [
31]. Protein intake above the minimum recommended value of 1.2 g/kg/d was also observed in most adolescent athletes [
15,
16,
32,
33]. Therefore, the prevalence of coaches having the intention to recommend a higher consumption of foods rich in proteins could be considered as reasonable.
Subjective norm was identified as the main correlate of coaches’ intentions to recommend a higher consumption of foods rich in carbohydrates and foods rich in proteins to their adolescent athletes. These results suggest that perceived social pressure towards carbohydrate and protein recommendations has a stronger impact than the perceived advantages and disadvantages, or the perceived barriers and facilitating factors on the intention to adhere to these behaviours. Indeed, carbohydrate and protein recommendations before, during and after training or competition are more complex than hydration recommendations, and require a minimum of knowledge and abilities regarding general sports nutrition. Such constraints may explain why coaches are more subject to external influence. While all referents representing normative beliefs were significantly associated with subjective norm in correlation analyses, parents of athletes seemed to be an important referent of coaches’ intentions to recommend a higher consumption of foods rich in carbohydrates and foods rich in proteins to their athletes. It can be speculated that because parents of athletes aged 12–17 years are mostly responsible for food purchase and preparation [
34] and they also represent an important source of nutrition information for athletes [
6,
11], coaches rely on parents’ opinions for these behaviours. Future interventions should focus in educating coaches and developing their skills related to general sports nutrition so they could be more influenced by evidenced-based sources of nutrition information for these behaviours.
The high prevalence (i.e., 91.9%) of coaches having the intention to recommend an increase in hydration to improve performance seems appropriate since adequate fluid intake before, during and after exercise is important for health and optimal performance, though an inter-individual variability is now recognized on the impact of dehydration on sport performance [
31]. Moreover, studies among adolescent athletes generally showed that they have suboptimal hydration practices [
17,
35,
36]. This high prevalence of intention combined with all coaches having reported they had recommanded hydration to their athletes in the last 12 months [
10] suggests that this recommendation is more common and less ambiguous. This may explain why perceived behavioural control was the most important determinant of coaches’ intention to recommend hydration. When a referent group performs a behaviour, which is considered as the descriptive norm, it may indirectly influence perceived behavioural control over this behaviour [
23]. Because water is usually free and easily accessible, coaches might perceive few barriers to provide this recommendation.
Finally, the results of this study highlight group of sport differences in coaches’ intention to provide some specific sports nutrition recommendations, i.e., foods rich in proteins. Group of sport differences were also observed for determinants of coaches’ intention to recommend the consumption of foods rich in proteins and hydration. These differences may be explained by cultural aspects and physical demands of each type of sports.
Strengths and limits
To our knowledge, this study is the first to assess coaches’ intentions to provide different sports nutrition recommendations to their athletes and the determinants of their intentions. In addition to the results on nutrition knowledge and nutritional practices provided by French Canadian high school coaches presented in Couture et al. 2015 [
10], this study yields a broad understanding of coaches' sports nutrition practices representing key information for the development of training regarding general sports nutrition. Questions measuring behavioural, normative and control beliefs were based on the literature and on group discussions among researchers. Moreover, very few theoretical frameworks provide specific guidelines for questionnaire development, as does the TPB, which ensures the quality of the recorded data [
22]. In future studies, focus groups could be used to identify modal behavioural, normative and control beliefs in a sample of the study population to ensure that all coaches’ beliefs are considered. The small number of coaches and the high proportion of football coaches also limit the generalization of results to all sports. The sample size was also a constraint for the consideration of specific determinants and beliefs related to the intention to recommend the three different sports nutrition practices in the two groups of sports. Specific sport cultural aspects also need to be considered, such as the use of protein supplements among young football players [
37], which can influence coaches’ intention to recommend the sports nutrition practices assessed in the present study. Moreover, due to time and financial constraints, it was not possible to assess the actual sports nutrition recommendations provided by coaches, but the past behaviour was nonetheless assessed and presented elsewhere [
10]. Although intention is viewed as the most proximal determinant of a behaviour, one cannot assume that coaches actually provide the recommendations assessed in this study, as a meta-analysis of meta-analyses showed that the intention account for an important part (i.e., 28%), but not all of the variance of a behaviour [
38]. In this context, future studies should be performed with a larger cohort from a greater variety of sports and should assess the actual behaviour, i.e., recommendations on sports nutrition provided to their athletes, using tools such as a logbook or a diary.
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