Pre-competition hormonal and psychological levels of elite hockey players: Relationship to the ‘home advantage’

Abstract

The home advantage is a robust phenomenon that occurs in the world of amateur and professional sport. Athletic teams have been shown to win significantly more games in their home venue as compared to their opponents' venue. Studies have suggested that the home advantage may be related to familiarity with the facility, increased crowd density and even pre-competition hormonal levels. The present study investigated pre-competition physiological and psychological states of elite hockey players in the home and away venues. Physiological measures included salivary cortisol and testosterone, which were assessed using enzyme immunoassays. In addition, pre-competition psychological states were assessed using the Competitive State Anxiety Inventory-2. Physiological measures indicated that the players had significantly higher pre-game testosterone when playing in their home venue as compared to their opponents' venue (t(13) = 2.29, p = 0.04); however, this difference was not due to a pre-game rise in testosterone while competing at home. Furthermore, players showed a trend toward higher pre-game cortisol when playing in their home venue (t(13) = 1.96, p = 0.07). Psychological measures indicated that players were more self-confident when playing in their home venue (t(13) = 2.8, p = 0.008) and also had higher somatic (t(13) = 2.3, p = 0.02) and cognitive anxiety (t(13) = 1.87, p = 0.04) when playing in their opponents' venue. The present study supports the notion that there are differences in pre-competition hormonal and psychological states that may play a key role in the ‘home advantage’.

Introduction

The ‘home advantage’ is a robust effect in that “home teams in sport competitions win over 50% of the games played under a balanced home and away schedule” [1]. A considerable amount of research has focused on factors assumed to underlie this phenomenon ([1], see [2] for review), and these factors are as follows: familiarity with facility, crowd density, travel and officiating.

It has been proposed that familiarity with one's facility may be advantageous to the home team. A recent study by Pollard [3] found that the home advantage was decreased for professional athletic teams who relocated to a new home venue. Approximately 72% of National Hockey League, National Basketball Association and Major League Baseball teams that relocated experienced a decrease in their win/loss ratio at home.

It has also been proposed that crowd size and density may play an important role in the home advantage. Agnew and Carron [4] found that the only significant predictor of game outcome was crowd density. The authors indicate that, as crowd density increases, so does the home advantage. In contrast, another study found that crowd size rather than crowd density was related to the home advantage [5].

An additional area of interest that has received a considerable amount of attention is the effect of travel and the home advantage. Teams traveling to venues by airplane or bus may, in fact, be at a disadvantage when playing in their opponents' venue. Professional hockey teams (National Hockey League) crossing multiple time zones [6] and basketball teams traveling in excess of 200 miles [7] were more likely to lose games played in their opponents' venue than in their home venue.

Another factor thought to influence the ‘home advantage’ is officiating. That is, it is believed that the home team has an advantage over the opposing team because the officials or referees make decisions or calls that favor the home team. It has been suggested that the officials/referees make more calls in favor of the home team mainly due to the influence that the home crowd may have on the decision maker [8].

Although these areas of research enhance the current understanding of the home advantage, fewer studies have investigated pre-contest physiological and psychological states of athletes in the home and away venues. Recent studies have now begun to focus on the pre-competition psychological and physiological states of athletes playing in their home and away venues. A study by Bray, Jones and Owen [9] found that athletes had significantly higher pre-game self-confidence and self-efficacy for games played in the home venue. They also found that athletes had significantly higher pre-game somatic and cognitive anxiety when playing in their opponents' venue. Although this study does not explain the advantage of having higher self-confidence and lower anxiety when performing in the home venue, the results do indicate that there are important psychological differences for games played at home and those played at the opponents' venues. In addition, it was found that basketball players had higher pre-game self-confidence when playing in their home venue [10]. Despite these findings, some studies have also failed to find any difference in anxiety depending on game location [10], [11]. Therefore, the results on the psychological states of athletes prior to competition and game location remain equivocal.

In addition to research examining the relationship between pre-game psychological states of athletes and game location, a recent study [12] looked at the pre-game testosterone levels of soccer players. The results of this study revealed that athletes had significantly higher pre-game testosterone when playing in their home venue compared to playing in their opponents' venue. This finding is very important because it suggests that humans may express higher levels of testosterone when defending their home territory. This territoriality phenomenon has been demonstrated in several primate [13] and rodent [14] studies. Wingfield et al. [15] formulated a Challenge Hypothesis to explain the rise in testosterone associated with territorial behavior. The authors state that males will display territorial behavior during times of competition, especially during breeding season. This territorial behavior has been associated with an increase in overt aggression as well as a rise in testosterone.

Higher testosterone levels have been associated with dominant and assertive behavior [16], vigor and activation [17], [18] and visual-spatial ability [19]. In addition, a biosocial model of social status has been proposed in order to explain the relationship between status and testosterone levels [20]. Mazur [20] states that as one maintains or gains social status during a status contest, one's testosterone levels will presumably rise, making them more likely to engage assertively, competitively and successfully in future status contests. Testosterone levels have been shown to increase in winners of status contests [21], [22], [23], [24], [25] and to decrease in losers [24], [25]. Furthermore, rodent studies have also demonstrated this phenomenon [26]. These studies suggest that the act of winning leads to a significant increase in testosterone which may enable one to be more assertive, competitive and aggressive in subsequent status contests, thus increasing the likelihood of maintaining and/or gaining status.

Heightened testosterone after a victory has been proposed to increase the organism's chances of winning future status contests [20]. We propose that higher testosterone levels observed prior to competition in one's home venue may be related to the athlete's belief that playing in one's home venue provides for a disproportionate advantage to the home team. Thus, playing at home may be related to a sense of higher social status for the members of the home team, leading to a heightened level of pre-game testosterone. As demonstrated, testosterone has been linked to aggressive and assertive behavior, both of which are very important in the sport of competitive ice hockey. Therefore, higher testosterone prior to games played at home may facilitate the expression of these crucial behavioral characteristics.

In addition to research on competition and testosterone, many studies have begun to investigate the stress experienced by athletes before, during and after competition [21], [22], [37], [40], [41]. Researchers have been able to objectively assess stress responses by measuring levels of cortisol from saliva. Cortisol has been identified as a reliable marker of hypothalamic pituitary adrenal axis (HPA) activation (see [27] for review) and is a useful means of evaluating physiological arousal prior to games played in the home and away venues.

Research incorporating the psychological and physiological states of athletes prior to competition in both home and away settings may provide additional insight into the concept of the ‘home advantage’. The purpose of this study was to investigate the pre-game physiological and psychological states of elite athletes in both home and away competition. It was hypothesized that athletes would have higher pre-game testosterone levels when playing in their home venue. Furthermore, we predicted that cortisol levels would be higher for games played away from the team's home arena. In addition, we predicted that pre-game self-confidence would be higher for home games, while cognitive and somatic anxiety would be higher for away games.

Along with the main hypotheses proposed, we also sought to investigate the relationship between pre-game psychological and physiological measures and post-game ratings of performance. It was predicted that there would be a significant correlation between pre-game testosterone and post-game performance ratings. Moreover, it was hypothesized that self-confidence, somatic anxiety and cognitive anxiety would also be related to post-game performance ratings.

We were also interested in looking at the relationship between salivary cortisol measures (physiological activation) and state somatic anxiety as measured by the Competitive State Anxiety Inventory-2 (CSAI-2). Previous reports have demonstrated mixed results on the relationship between physiological and psychological measures of activation [28], [29].