Psychological trauma associated with long-term injury can cause athletes to experience intense stress-like symptoms and considerable negative affect (e.g., Tracey, 2003; Udry, 1997). Due to the nature of competitive sport, however, it is thought that injured athletes inhibit these emotions to the detriment of their physical health. The present study examined Pennebaker’s (1989) emotional disclosure paradigm within a sporting context. It was hypothesized that writing about a traumatic injury would reduce athletes’ mood disturbance and stress during rehabilitation. Further, it was believed that these changes would correspond with an increase in immune expression from pre- to postintervention. Elite injured athletes (N = 9) rehabilitating from anterior cruciate ligament surgery participated in the 3-day writing intervention, consisting of 3 X 20 min writing sessions, during which athletes disclosed negative emotions associated with their injury and rehabilitation experiences. Measures were taken at six time-points (T1-T6), with pre- and postintervention phases lasting for 4 weeks each. Measures consisted of psychological stress (intrusion and avoidance), total mood disturbance, and relative cell-counts/µL for circulating T-cells (CD4/8) and NK cells (CD16/56). Repeated-measures ANOVAs showed a signifcant main effect of time for intrusion, F(5, 70) = 5.83, p =.001, η2 = .29 and avoidance, F(5, 70) = 5.73, p =.002, η2 = 0.29 subscales; mood disturbance, F(5, 70) = 3.71, p= 0.005, η2 = 0.21; and CD4+, F(5, 65) = 2.39, p= 0.048, η2 = .16. Subsequent linear contrasts provided further evidence of significant prepost differences among the stress, mood state, and immune variables. These results suggest that the written disclosure intervention has potential psycho-immunological benefits for athletes rehabilitating from long-term injury.
Aditi Mankad, Sandy Gordon and Karen Wallman
Aditi Mankad, Sandy Gordon and Karen Wallman
The present study features a psycholinguistic analysis, using Pennebaker’s (1989) emotional disclosure paradigm, of an athlete’s experience in recovering from injury. “GL,” a male athlete rehabilitating from anterior cruciate ligament reconstruction, participated in a 9-week testing protocol. A 3-day intervention was used, consisting of three 20-minute writing sessions, which promoted disclosure of negative emotions associated with injury and rehabilitation. In addition, measures of stress, mood disturbance, and self-esteem were administered from pre- to postintervention and at follow-up. Results revealed decreases in stress and mood disturbance, as well as an increase in self-esteem. Analysis of writing samples revealed increased use of linguistic markers indicating affective awareness. Findings also highlighted the importance of emotional disclosure and cognitive integration in reducing stress and enhancing understanding of injury.
Aditi Mankad, Sandy Gordon and Karen Wallman
The present study adopted a qualitative, exploratory approach to describe the underlying emotional climate among injured athletes within team sport environments. Nine elite athletes undergoing long-term injury rehabilitation (LTIR) participated in semi-structured interviews to describe their LTIR experience. A general inductive analysis extracted three higher-order themes: (a) emotional trauma, (b) emotional climate, and (c) emotional acting. Athletes reported experiencing emotional trauma throughout LTIR. To maintain in-group norms, they described engaging in avoidance behaviors and reported suppressing negative affect for fear of negative evaluation. They also reported frequently controlling emotions in public using acting strategies. Athletes perceived these emotionally inhibitive behaviors as encouraged within their team environment. These results have important implications for the identification and treatment of emotionally destructive behaviors that could potentially delay an athlete’s psychological rehabilitation from athletic injury.
Matthew Zimmermann, Grant Landers, Karen E. Wallman and Jacinta Saldaris
This study examined the physiological effects of crushed ice ingestion before steady state exercise in the heat. Ten healthy males with age (23 ± 3 y), height (176.9 ± 8.7 cm), body-mass (73.5 ± 8.0 kg), VO2peak (48.5 ± 3.6 mL∙kg∙min-1) participated in the study. Participants completed 60 min of cycling at 55% of their VO2peak preceded by 30 min of precooling whereby 7 g∙kg-1 of thermoneutral water (CON) or crushed ice (ICE) was ingested. The reduction in Tc at the conclusion of precooling was greater in ICE (-0.9 ± 0.3 °C) compared with CON (-0.2 ± 0.2 °C) (p ≤ .05). Heat storage capacity was greater in ICE compared with CON after precooling (ICE -29.3 ± 4.8 W∙m-2; CON -11.1 ± 7.3 W∙m-2, p < .05). Total heat storage was greater in ICE compared with CON at the end of the steady state cycle (ICE 62.0 ± 12.5 W∙m-2; CON 49.9 ± 13.4 W∙m-2, p < .05). Gross efficiency was higher in ICE compared with CON throughout the steady state cycle (ICE 21.4 ± 1.8%; CON 20.4 ± 1.9%, p < .05). Ice ingestion resulted in a lower thermal sensation at the end of precooling and a lower sweat rate during the initial stages of cycling (p < .05). Sweat loss, respiratory exchange ratio, heart rate and ratings of perceived exertion and thirst were similar between conditions (p > .05). Precooling with crushed ice led to improved gross efficiency while cycling due to an increased heat storage capacity, which was the result of a lower core temperature.
Kagan J. Ducker, Brian Dawson and Karen E. Wallman
Beta-alanine supplementation has been shown to improve exercise performance in short-term, high-intensity efforts.
The aim of this study was to assess if beta-alanine supplementation could improve 800 m track running performance in male recreational club runners (n = 18).
Participants completed duplicate trials (2 presupplementation, 2 postsupplementation) of an 800 m race, separated by 28 days of either beta-alanine (n = 9; 80 mg·kg−1BM·day−1) or placebo (n = 9) supplementation.
Using ANCOVA (presupplementation times as covariate), postsupplementation race times were significantly faster following beta-alanine (p = .02), with post- versus presupplementation race times being faster after beta-alanine (–3.64 ± 2.70 s, –2.46 ± 1.80%) but not placebo (–0.59 ± 2.54 s, –0.37 ± 1.62%). These improvements were supported by a moderate effect size (d = 0.70) and a very likely (99%) benefit in the beta-alanine group after supplementation. Split times (ANCOVA) at 400 m were significantly faster (p = .02) postsupplementation in the beta-alanine group, compared with placebo. This was supported by large effect sizes (d = 1.05–1.19) and a very likely (99%) benefit at the 400 and 800 m splits when comparing pre- to postsupplementation with beta-alanine. In addition, the first and second halves of the race were faster post- compared with presupplementation following beta-alanine (1st half –1.22 ± 1.81 s, likely 78% chance of benefit; 2nd half –2.38 ± 2.31 s, d = 0.83, very likely 98% chance of benefit). No significant differences between groups or pre- and postsupplementation were observed for postrace blood lactate and pH.
Overall, 28 days of beta-alanine supplementation (80 mg·kg-1BM·day-1) improved 800 m track performance in recreational club runners.
Matthew Zimmermann, Grant Justin Landers and Karen Elizabeth Wallman
This study examined the effects of precooling via ice ingestion on female cycling performance in hot, humid conditions. Ten female endurance athletes, mean age (28 ± 6 y), height (167.6 ± 6.5 cm) and body-mass (68.0 ± 11.5 kg) participated in the study. Participants completed an 800 kJ cycle time-trial in hot, humid conditions (34.9 ± 0.3 °C, 49.8 ± 3.5% RH). This was preceded by the consumption of 7 g∙kg-1 of crushed ice (ICE) or water (CON). There was no difference in performance time (CON 3851 ± 449 s; ICE 3767 ± 465 s), oxygen consumption (CON 41.6 ± 7.0 ml∙kg∙min-1; ICE 42.4 ± 6.0 ml∙kg∙min-1) or respiratory exchange ratio (CON 0.88 ± 0.05; ICE 0.90 ± 0.06) between conditions (p > .05, d < 0.5). Core and skin temperature following the precooling period were lower in ICE (Tc 36.4 ± 0.4 °C; Tsk 31.6 ± 1.2 °C) compared with CON (Tc 37.1 ± 0.4 °C; Tsk 32.4 ± 0.7 °C) and remained lower until the 100 kJ mark of the cycle time-trial (p < .05, d > 1.0). Sweat onset occurred earlier in CON (228 ± 113 s) compared with ICE (411 ± 156 s) (p < .05, d = 1.63). Mean thermal sensation (CON 1.8 ± 2.0; ICE 1.2 ± 2.5, p < .05, d = 2.51), perceived exertion (CON 15.3 ± 2.9; ICE 14.9 ± 3.0, p < .05, d = 0.38) and perceived thirst (CON 5.6 ± 2.2; ICE 4.6 ± 2.4, p < .05, d = 0.98) were lower in ICE compared with CON. Crushed ice ingestion did not improve cycling performance in females, although perceptual responses were reduced.
Matthew Zimmermann, Grant Landers, Karen Wallman and Georgina Kent
This study compared the effects of precooling (ice ingestion) and heat-acclimation training on cycling time-trial (CTT) performance in the heat. Fifteen male cyclists/triathletes completed two 800-kJ CTTs in the heat, with a 12-d training program in between. Initially, all participants consumed 7 g/kg of water (22°C) in 30 min before completing an 800-kJ CTT in hot, humid conditions (pre-CTT) (35°C, 50% relative humidity [RH]). Participants were then split into 2 groups, with the precooling group (n = 7) training in thermoneutral conditions and then undergoing precooling with ice ingestion (7 g/kg, 1°C) prior to the final CTT (post-CTT) and the heat-acclimation group (n = 8) training in hot conditions (35°C, 50% RH) and consuming water (7 g/kg) prior to post-CTT. After training in both conditions, improvement in CTT time was deemed a likely positive benefit (precooling −166 ± 133 s, heat acclimation −105 ± 62 s), with this result being similar between conditions (d = 0.22, −0.68–1.08 90% confidence interval [CI]). Core temperature for post-CTT was lower in precooling than in heat acclimation from 20 min into the precooling period until the 100-kJ mark of the CTT (d > 0.98). Sweat onset occurred later in precooling (250 ± 100 s) than in heat acclimation (180 ± 80 s) for post-CTT (d = 0.65, −0.30–1.50 90% CI). Thermal sensation was lower at the end of the precooling period prior to post-CTT for the precooling trial than with heat acclimation (d = 1.24, 0.90–1.58 90% CI). Precooling with ice ingestion offers an alternative method of improving endurance-cycling performance in hot conditions if heat acclimation cannot be attained.
Kagan J. Ducker, Brian Dawson and Karen E. Wallman
Beta-alanine supplementation has been shown to improve exercise performance in short-term high-intensity efforts. However, whether supplementation with beta-alanine is ergogenic to actual sporting events remains unclear and should be investigated in field testing or race simulations.
The aim of this study was to assess if beta-alanine supplementation could improve 2,000-m rowing-ergometer performance in well-trained male rowers.
Participants (N = 16) completed duplicate trials (2 × before supplementation and 2 × after supplementation) of a 2,000-m rowing-ergometer race separated by 28 days of either beta-alanine (n = 7; 80 mg · kg−1 BM · d−1) or placebo (n = 9; glucose) supplementation.
Beta-alanine group (pooled) race times improved by 2.9 ± 4.1 s and placebo group slowed by 1.2 ± 2.9 s, but these results were inconclusive for performance enhancement (p = .055, ES = 0.20, smallest worthwhile change = 49% beneficial). Race split times and average power outputs only significantly improved with beta-alanine at the 750-m (time –0.7 s, p = .01, power +3.6%, p = .03) and 1,000-m (time –0.5 s, p = .01, power +2.9%, p = .02) distances. Blood La− and pH postrace values were not different between groups before or after supplementation.
Overall, 28 d of beta-alanine supplementation with 80 mg · kg−1 BM · d−1 (~7 g/d) did not conclusively improve 2,000-m rowing-ergometer performance in well-trained rowers.
Cameron P. Brewer, Brian Dawson, Karen E. Wallman and Kym J. Guelfi
Research into supplementation with sodium phosphate has not investigated the effects of a repeated supplementation phase. Therefore, this study examined the potential additive effects of repeated sodium phosphate (SP) supplementation on cycling time-trial performance and peak oxygen uptake (VO2peak). Trained male cyclists (N = 9, M ± SD VO2peak = 65.2 ± 4.8 ml · kg−1 · min−1) completed baseline 1,000-kJ time-trial and VO2peak tests separated by 48 hr, then ingested either 50 mg · kg fat-free mass−1 · d−1 of tribasic SP or a combined glucose and NaCl placebo for 6 d before performing these tests again. A 14-d washout period separated the end of one loading phase and the start of the next, with 2 SP and 1 placebo phase completed in a counterbalanced order. Although time-trial performance (55.3–56.5 min) was shorter in SP1 and SP2 (~60–70 s), effect sizes and smallest-worthwhile-change values did not differ in comparison with baseline and placebo. However, mean power output was greater than placebo during time-trial performance at the 250-kJ and 500-kJ time points (p < .05) after the second SP phase. Furthermore, mean VO2peak values (p < .01) were greater after the SP1 (3.5–4.3%), with further improvements (p < .01) found in SP2 (7.1–7.7%), compared with baseline and placebo. In summary, repeated SP supplementation, ingested either 15 or 35 d after initial loading, can have an additive effect on VO2peak and possibly time-trial performance.
Jessica S. West, Tom Ayton, Karen E. Wallman and Kym J. Guelfi
Ingestion of an acute dose of phosphate has been shown to attenuate energy intake in the subsequent meal. This raises the question of whether the practice of phosphate supplementation over a number of days by athletes to enhance performance also influences energy intake. This study investigated the effect of 6 d of phosphate supplementation on appetite and energy intake, as well as aerobic capacity, in trained individuals. Twenty participants completed two 6-d phases of supplementation with either sodium phosphate (50 mg/kg of fat-free mass per day) or a placebo in a double-blinded, counterbalanced design. On Days 1, 2, and 6 of supplementation, a laboratory meal was provided to assess appetite and ad libitum energy intake. All other food and drink consumed during each supplementation phase were recorded in a food diary. After the 6 d of supplementation, peak aerobic capacity (VO2peak) was assessed. There was no difference in energy intake at the laboratory meal after an acute dose (i.e., on Day 1; placebo 2,471 ± 919 kJ, phosphate 2,353 ± 987 kJ; p = .385) or prolonged supplementation with sodium phosphate (p = .581) compared with placebo. Likewise, there was no difference in VO2peak with phosphate supplementation (placebo 52.6 ± 5.2 ml · kg−1 · min−1, phosphate 53.3 ± 6.1 ml · kg−1 · min−1; p = .483). In summary, 6 d of sodium phosphate supplementation does not appear to influence energy intake. Therefore, athletes supplementing with sodium phosphate can do so without hindering their nutritional status. However, given that phosphate supplementation failed to improve aerobic capacity, the ergogenic benefit of this supplement remains questionable.