The purpose of this study was to compare markers of hydration during submaximal exercise and subsequent time trial performance when consuming water (PW) or coconut water (CW). There was also a secondary aim to assess the palatability of CW during exercise and voluntary intake during intense exercise. 10 males (age 27.9 ± 4.9 years, body mass 78.1 ± 10.1kg, average max minute power 300.2 ± 28.2W) completed 60-min of submaximal cycling followed by a 10-km time trial on two occasions. During these trials participants consumed either PW or CW in a randomized manner, drinking a 250 ml of the assigned drink between 10–15 min, 25–30 min and 40–45 min, and then drinking ad libitum from 55-min until the end of the time trial. Body mass and urine osmolality were recorded preexercise and then after 30-min, 60-min, and post time trial. Blood glucose, lactate, heart rate, rate of perceived exertion (RPE; 6–20) and ratings of thirst, sweetness, nausea, fullness and stomach upset (1 =very low/none, 5= very high) were recorded during each drink period. CW did not significantly improve time trial performance compared with PW (971.4 ± 50.5 and 966.6 ± 44.8 s respectively; p = .698) and there was also no significant differences between trials for any of the physiological variables measured. However there were subjective differences between the beverages for taste, resulting in a significantly reduced volume of voluntary intake in the CW trial (115 ± 95.41 ml and 208.7 ± 86.22 ml; p < .001).
Daniel J. Peart, Andy Hensby and Matthew P. Shaw
Catriona A. Burdon, Nathan A. Johnson, Phillip G. Chapman and Helen T. O’Connor
Beverage palatability is known to influence fluid consumption during exercise and may positively influence hydration status and help prevent fatigue, heat illness, and decreased performance.
The aims of this review were to evaluate the effect of beverage temperature on fluid intake during exercise and investigate the influence of beverage temperature on palatability.
Citations from multiple databases were searched from the earliest record to November 2010 using the terms beverage, fluid, or water and palatability, preference, feeding, and drinking behavior and temperature. Included studies (N = 14) needed to use adult (≥18 yr) human participants, have beverage temperatures ≤50 °C, and measure consumption during exercise and/or palatability.
All studies reporting palatability (n = 10) indicated that cold (0–10 °C) or cool (10–22 °C) beverages were preferred to warmer ones (control, ≥22 °C). A meta-analysis on studies reporting fluid consumption (n = 5) revealed that participants consumed ~50% (effect size = 1.4, 0.75–2.04, 95% CI) more cold/cool beverages than control during exercise. Subanalysis of studies assessing hydration status (n = 4) with consumption of cool/cold vs. warm beverages demonstrated that dehydration during exercise was reduced by 1.3% of body weight (1.6–0.9%, 95% CI; p < .001).
Cool beverage temperatures (<22 °C) significantly increased fluid palatability, fluid consumption, and hydration during exercise vs. control (≥22 °C).
Dennis H. Passe, Mary Horn, John Stofan and Robert Murray
Palatability and voluntary intake of 4 beverages commonly available to athletes were compared in a laboratory exercise protocol designed to mimic aerobic training or competitive conditions in which limited time is available for drinking. Diluted orange juice (DOJ), homemade 6% carbohydrate-electrolyte sports beverage (HCE), commercially available 6% carbohydrate-electrolyte sports beverage (CCE), and water (W) were tested. Fifty adult triathletes and runners (34 males, 16 females) exercised for 75 min at 80–85% of age-predicted heart rate, during which time they were given brief access (60 s) to one of the beverages after 30 min and 60 min of exercise. Results indicated that for overall palatability, CCE > W, HCE, DOJ; W > DOJ, and for amount of beverage consumed, CCE > W, HCE, DOJ; HCE > W, DOJ. The palatability of these beverages varied substantially, as did their voluntary intakes during exercise.
Craig A. Horswill
As a result of exercise-induced sweating, athletes and trained individuals can lose up to 3 L of fluid per hour. Fluid replacement is required to maintain hydration and allow the athlete to continue to perform. Inadequate fluid intake will adversely affect temperature regulation, cardiovascular function, and muscle metabolism. To maximize fluid intake and effectively replace fluid, athletes must employ behavioral strategies. Athletes can also select beverages with characteristics that complement their behavioral efforts. Palatability, rapid absorption, retention of the fluid, and ergogenicity are the major attributes to consider for enhancing hydration during training and physical activity.
Nancy S. Diehl, Britton W. Brewer, Judy L. Van Raalte, Darlene Shaw, Patricia L. Fiero and Marit Sørensen
In a study examining the relationships between two social psychological factors and exercise partner preferences, 97 women (mean age 32.42; SD = 9.85 years) provided demographic information, indicated their exercise partner preference, and completed measures of social physique anxiety (SPA) and perceived social discomfort (PSD) in exercise settings. Chi-square analyses on PSD and exercise partner preferences revealed significant effects, X2 (4) = 34.53, p < .001. Logistic regression revealed an effect for the SPA X PSD interaction, LR = 0.97, p < .01. When PSD was low, SPA had little impact on the odds of selecting a partner. When PSD and SPA were high, there were far lower odds of selecting an exercise partner. Overall, based upon the results, the number of exercise partners may be an important issue for women and women with high SPA may use an exercise partner to help moderate their anxiety, thereby increasing the palatability of the exercise setting.
The triumphal track and field performances of British distance runner, Mo Farah, at the London 2012 Olympic Games were lauded both for their athletic endeavor and for their perceived validation of the rhetoric of ethnic and cultural diversity and inclusion in which the Games were ensconced. By analyzing coverage of the athlete’s achievements in mainstream British newspapers, this article presents a more complicated and critical reading of the relationship between Britishness, multiculture, the politics of inclusion and the London Games. Employing a Critical Discourse Analysis approach, the article shows that Farah was constructed and represented by the media using narratives that are familiar, palatable and reassuring to the public; and that sustain hegemonic models of racialised nationhood and dominant ideologies around sport.
Brenton J. Baguley, Jessica Zilujko, Michael D. Leveritt, Ben Desbrow and Christopher Irwin
The aim of this study was to compare the effect of ad libitum intake of a milk-based liquid meal supplement against a carbohydrate-electrolyte sports drink following exercise induced fluid loss. Seven male participants (age 22.3 ± 3.4 years, height 179.3 ± 7.9 cm, body mass 74.3 ± 7.3 kg; mean ± SD) completed 4 separate trials and lost 1.89 ± 0.44% body mass through moderate intensity exercise in the laboratory. After exercise, participants consumed ad libitum over 2 h a milk-based liquid meal supplement (Sustagen Sport) on two of the trials (S1, S2) or a carbohydrate-electrolyte sports drink (Powerade) on two of the trials (P1, P2), with an additional 1 hr observational period. Measures of body mass, urine output, gastrointestinal tolerance and palatability were collected throughout the recovery period. Participants consumed significantly more Powerade than Sustagen Sport over the 2 h rehydration period (P1 = 2225 ± 888 ml, P2 = 2602 ± 1119 mL, S1 = 1375 ± 711 mL, S2 = 1447 ± 857 ml). Total urine output on both Sustagen trails was significantly lower than the second Powerade trial (P2 = 1447 ± 656 ml, S1 = 153 ± 62 ml, S2 = 182 ± 118 mL; p < .05) and trended toward being lower compared with the first Powerade trial (P1 = 1057 ± 699 ml vs. S1, p = .067 and vs. S2, p = .061). No significant differences in net fluid balance were observed between any of the drinks at the conclusion of each trial (P1 = −0.50 ±0. 46 kg, P2 = −0.40 ± 0.35 kg, S1 = −0.61 ± 0.74 kg, S2 = −0.45 ± 0.58 kg). Gastrointestinal tolerance and beverage palatability measures indicated Powerade to be preferred as a rehydration beverage. Ad libitum milk-based liquid meal supplement results in similar net fluid balance as a carbohydrate-electrolyte sports drink after exercise induced fluid loss.
Eric C. Haakonssen, Megan L. Ross, Louise E. Cato, Alisa Nana, Emma J. Knight, David G. Jenkins, David T. Martin and Louise M. Burke
Some athletes avoid dairy in the meal consumed before exercise due to fears about gastrointestinal discomfort. Regular exclusion of dairy foods may unnecessarily reduce intake of high quality proteins and calcium with possible implications for body composition and bone health. This study compared the effects of meals that included (Dairy) or excluded (Control) dairy foods on gastric comfort and subsequent cycling performance. Well-trained female cyclists (n = 32; mean ± SD; 24.3 ± 4.1 y; VO2peak 57.1 ± 4.9 ml/kg/min) completed two trials (randomized cross-over design) in which they consumed a meal (2 g/kg carbohydrate and 54 kJ/kg) 2 hr before a 90-min cycle session (80 min at 60% maximal aerobic power followed by a 10-min time trial; TT). The dairy meal contained 3 servings of dairy foods providing ~1350 mg calcium. Gut comfort and palatability were measured using questionnaires. Performance was measured as maximum mean power during the TT (MMP10min). There was no statistical or clinical evidence of an effect of meal type on MMP10min with a mean difference (Dairy – Control) of 4 W (95% CI [–2, 9]). There was no evidence of an association between pretrial gut comfort and meal type (p = .15) or between gut comfort delta scores and meal type postmeal (p = .31), preexercise (p = .17) or postexercise (p = .80). There was no statistical or clinical evidence of a difference in palatability between meal types. In summary, substantial amounts of dairy foods can be included in meals consumed before strenuous cycling without impairing either gut comfort or performance.
Louise M. Burke, Gregory R. Collier and Mark Hargreaves
The glycemic index (GI) provides a way to rank foods rich in carbohydrate (CHO) according to the glucose response following their intake. Consumption of low-GI CHO-rich foods may attenuate the insulin-mediated metabolic disturbances associated with CHO intake in the hours prior to exercise, better maintaining CHO availability. However, there is insufficient evidence that athletes who consume a low-GI CHO-rich meal prior to a prolonged event will gain clear performance benefits. The ingestion of CHO during prolonged exercise promotes CHO availability and enhances endurance and performance, and athletes usually choose CHO-rich foods and drinks of moderate to high GI to achieve this goal. Moderate- and high-GI CHO choices appear to enhance glycogen storage after exercise compared with low-GI CHO-rich foods. However, the reason for this is not clear. A number of attributes of CHO-rich foods may be of value to the athlete including the nutritional value of the food or practical issues such as palatability, portability, cost, gastric comfort, or ease of preparation.
Ben Desbrow, Clare Minahan and Michael Leveritt
This study investigated whether a change in beverage favor during endurance cycling improves subsequent performance. Eight trained male athletes (age 24.3 ± 3.9 y, weight 74.7 ± 6.0 kg, peak O2 uptake [VO2peak] 65.4 ± 5.4 mL·kg−1·min−1; mean ± SD) undertook 3 trials, with training and diet being controlled. Trials consisted of 120 min of steady-state (SS) cycling at ~70% VO2peak, immediately followed by a 7-kJ/kg time trial (TT). During exercise subjects were provided with fluids every 20 min. After 80 min of SS cycling subjects either continued drinking the same-favor sports drink or changed to an alternate favor—either an alternate-favor sports drink (AFSD) or cola. All beverages were carbohydrate and volume matched. Changing drink favor caused no significant change in TT time (sports drink 27:16 ± 03:12, AFSD 27:06 ± 03:16, cola 27:03 ± 02:42; min: s). The various favors produced no treatment effects on heart rate, blood glucose, or rating of perceived exertion throughout the SS exercise protocol. The influence of other taste variables such as palatability, bitterness, or timing of favor change on endurance-exercise performance requires more rigorous investigation.