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The purpose of this study was to examine the effect of prior glycerol loading on competitive Olympic distance triathlon performance (ODT) in high ambient temperatures. Ten (3 female and 7 male) well-trained triathletes (VO_2max = 58.4 ±2.4 ml-kg⁻¹ min⁻¹; best ODT time = 131.5 ± 2.6 min) completed 2 ODTs (1.5-km swim, 40-km bicycle, 10-km run) in a randomly assigned (placebo/ glycerol) double-blind study conducted 2 weeks apart. The wet-bulb globe temperature (outdoors) was 30.5 + 0.5 °C (relative humidity: 46.3 ± 1.1%; hot) and 25.4 + 0.2 °C (relative humidity: 51.7 ± 2.4%; warm) for day 1 and day 2, respectively. The glycerol solution consisted of 1.2 g of glycerol per kilogram of body mass (BM) and 25 ml of a 0.75 g · kg⁻¹ BM carbohydrate solution (Gatorade®) and was consumed over a 60-min period, 2 hours prior to each ODT. Measures of performance (ODT time), fluid retention, urine output, blood plasma volume changes, and sweat loss were obtained prior to and during the ODT in both the glycerol and placebo conditions. Following glycerol loading, the increase in ODT completion time between the hot and warm conditions was significantly less than the placebo group (placebo 11:40 min vs. glycerol 1:47 min; p < .05). The majority of the performance improvement occurred during the final 10-km run leg of ODT on the hot day. Hyperhydration occurred as a consequence of a reduced diuresis (p < .05) and a subsequent increase in fluid retention (p < .05). No significant differences were observed in sweat loss between the glycerol and placebo conditions. Plasma volume expansion during the loading period was significantly greater (p < .05) on the hot day when glycerol appeared to attenuate the performance decrement in the heat. The present results suggest that glycerol hyperhydration prior to ODT in high ambient temperatures may provide some protection against the negative performance effects of competing in the heat.

Seven highly trained male triathletes, aged 18 to 35 years, were tested during two simulated Olympic distance triathlons to determine whether run performance was enhanced when consuming 177 ml of water at 8, 16, 24, and 32 kilometers (Early Trials) compared to consumption at 10, 20, 30, and 40 kilometers (Late Trials), during the cycling segment of the triathlon. Swim times for 1500 m were similar between trials; 40-km cycling times were ~10 s faster during the Late trials; however, 10-km run times were faster during the Early Trials (P < 0.02). No significant differences between run trials were found for the rating of perceived exertion, oxygen uptake, heart rate, and change in urine specific gravity. It was concluded that the consumption of fluids earlier in the cycle phase of the Olympic distance triathlon benefits the run and overall performance time.

Postexercise nutrition is a critical component of an athlete’s recovery from training and competition. However, little is known about athletes’ postexercise dietary practices or knowledge of dietary recommendations, particularly among masters athletes. The purpose of this study was to compare and contrast the knowledge of postexercise nutritional recommendations, and typical postexercise intakes of carbohydrate and protein, between masters and younger triathletes. 182 triathletes (Male = 101, Female = 81) completed an online survey distributed by Triathlon Australia. Knowledge of postexercise nutrition recommendations for protein and carbohydrate intake were assessed as a group, and contrasted between subgroups of masters (≥50 years) and younger triathletes (≤30 years). Using dietary recall, postexercise intakes of carbohydrate and protein were examined and contrasted between masters and younger triathletes. As a group, 43.1% and 43.9% of all triathletes answered, “I don’t know” when asked to identify the recommended postexercise carbohydrate and protein intakes, respectively. Dietary analysis revealed masters triathletes consumed significantly less carbohydrate (0.7 ± 0.4 g.kg^-1) postexercise than recommended (1.0 g.kg^-1; p = .001), and in comparison with younger triathletes (1.1 ± 0.6 g.kg^-1; p = .01). Postexercise protein intakes were similar between masters (19.6 ± 13.5 g) and younger (26.4 ± 15.8 g) triathletes. However, relative to body mass, masters triathletes consumed significantly less protein (0.3 ± 0.2 g.kg^-1) than younger triathletes (0.4 ± 0.2 g.kg^-1; p = .03), and consumed significantly less energy postexercise (22.7 ± 11.7 kJ.kg^-1) than younger triathletes (37.8 ± 19.2 kJ.kg^-1; p = .01). The present data suggests triathletes have poor knowledge of recommendations for postexercise carbohydrate and protein intakes. Furthermore, low postexercise intakes of carbohydrate and protein by masters athletes may impair acute recovery.

This study assessed the knowledge, prevalence, and quantity of caffeine use by athletes competing at the 2005 Ironman Triathlon World Championships. Caffeine-related questionnaires were self-administered to 140 (105 male and 35 female, 40.3 ± 10.7 y) athletes representing 16 countries. Fifty of these athletes further consented to immediate post-race blood samples for analysis of plasma caffeine and paraxanthine using high-performance liquid chromatography (HPLC). Seventy-two percent of 70 athletes correctly identified caffeine as being an unrestricted substance in triathlon. The majority of athletes [125 (89%)] were planning on using a caffeinated substance immediately prior to or throughout the race. Cola drinks (78%), caffeinated gels (42%), coffee (usually pre-race) (37%), energy drinks (13%), and NoDoz tablets (9%) were the most popular caffeinated choices. Mean ± standard deviation (and range) post race plasma caffeine and paraxanthine levels were 22.3 ± 20 μmol/L (1.7 to 98.4) and 9.4 ± 6 μmol/L (1.8 to 28.9), respectively. Seven athletes (14%) finished with plasma caffeine levels > 40 μmol/L. Plasma values from elite athletes did not differ from age group competitors. Despite the prevalence of its consumption and the training experience of this athletic group, over one quarter of athletes remained either confused or uninformed about caffeine’s legality. Levels of plasma caffeine taken immediately post race indicated that athletes typically finish with quantities of caffeine that have been shown to improve endurance performance (i.e., ~ 20 μmol/L or a dose of > 3 mg/kg body weight).

The ingestion of exogenous carbohydrates (CHO) during prolonged endurance exercise, such as long-distance triathlon, is considered beneficial with regard to performance. However, little is known about whether this performance benefit differs among different forms of CHO administration. To this end, the purpose of our study was to determine the impact of CHO ingestion from a semisolid source (GEL) on measures of performance and gastrointestinal (GI) comfort compared with CHO ingestion from a liquid source (LIQ). Nine well-trained triathletes participated in this randomized crossover study. Each participant completed a 60-min swim, 180-min bike exercise, and a 60-min all-out run in a laboratory environment under 2 conditions, once while receiving 67.2 ± 7.2 g · h⁻¹ (M ± SD) of CHO from GEL and once while receiving 67.8 ± 4.2 g · h⁻¹ of CHO from LIQ. The amount of fluid provided was matched among conditions. Respiratory exchange ratio (RER), blood glucose, and lactate as well as GI discomfort were assessed at regular intervals during the experiment. The distance covered during the final all-out run was not significantly different among participants ingesting GEL (11.81 ± 1.38 km) and LIQ (11.91 ± 1.53 km; p = .89). RER, blood glucose, and lactate did not differ significantly at any time during the experiment. Seven participants reported GI discomfort with GEL, and no athlete reported GI discomfort with LIQ (p = .016). This study suggests that administration of GEL does not alter long-distance triathlon performance when compared with LIQ, but GEL seems to be associated with reduced GI tolerance. Athletes should consider this a potential disadvantage of GEL administration during long-distance triathlon.

The aim of this study was to investigate the prerace and during-race carbohydrate intakes of elite-level triathletes contesting draft-legal Olympic-distance triathlon (ODT) events. Self-reported prerace and during-race nutrition data were collected at 3 separate ODT events from 51 elite senior and under-23 triathletes. One hundred twenty-nine observations of food and fluid intake representing actual prerace (n = 62) and during-race (n = 67) nutrition practices from 36 male and 15 female triathletes were used in the final analysis of this study. Female triathletes consumed significantly more carbohydrate on the morning before race start when corrected for body mass and race start time than their male counterparts (p < .05). Male and female triathletes consumed 26% more energy (kJ/kg) and 24% more carbohydrate (g/kg) when commencing a race after midday (1:00–1:30 p.m.) than for a late morning (11:00–11:15 a.m.) race start. During the race, triathletes consumed less than 60 g of carbohydrate on 66% of occasions, with average total race intakes of 48 ± 25 and 49 ± 25 g carbohydrate for men and women, respectively. Given average race times of 1:57:07 hr and 2:08:12 hr, hourly carbohydrate intakes were ~25 g and ~23 g for men and women, respectively. Although most elite ODT triathletes consume sufficient carbohydrate to meet recommended prerace carbohydrate intake guidelines, during-race carbohydrate intakes varied considerably, with many failing to meet recommended levels.

Energy balance of 10 male and 8 female triathletes participating in an Ironman event (3.8-km swim, 180-km cycle, 42.2-km run) was investigated. Energy intake (EI) was monitored at 7 designated points by dietary recall of food and fluid consumption. Energy expenditure (EE) during cycling and running was calculated using heart rate-V̇O₂ regression equations and during swimming by the multiple regression equation: Y = 3.65v + 0.02 W − 2.545 where Y is V̇O₂ in L · min⁻¹, v is the velocity in m · s⁻¹, Wis the body weight in kilograms. Total EE (10.036 ± 931 and 8570 ± 1014 kcal) was significantly greater than total El (3940 ± 868 and 3115 ± 914kcal, p < .001) formales and females, respectively, although energy balance was not different between genders. Finishing time was inversely related to carbohydrate (CHO) intake (g · kg⁻¹ · h⁻¹) during the marathonrun formales (r=−.75, p < .05), and not females, suggesting that increasing CHO ingestion during the run may have been a useful strategy for improving Ironman performance in male triathletes.