The aim of the present case study was to use real-time observations to investigate ultramarathon runners' timing of food and fluid intake per 15 km and per hour, and total bodyweight loss due to dehydration. The study included 5 male ultramarathon runners observed during a 120 km race. The research team members followed on a bicycle and continuously observed their dietary intake using action cameras. Hourly carbohydrate intake ranged between 22.1 and 62.6 g/h, and fluid intake varied between 260 and 603 mL/h. These numbers remained relatively stable over the course of the ultra-endurance marathon. Runners consumed food and fluid on average 3–6 times per 15 km. Runners achieved a higher total carbohydrate consumption in the second half of the race (p = 0.043), but no higher fluid intake (p = 0.08). Energy gels contributed the most to the total average carbohydrate intake (40.2 ± 25.7%). Post-race weight was 3.6 ± 2.3% (range 0.3–5.7%) lower than pre-race weight, revealing a non-significant (p = 0.08) but practical relevant difference. In conclusion, runners were able to maintain a constant timing of food and fluid intake during competition but adjusted their food choices in the second half of the race. The large variation in fluid and carbohydrate intake indicate that recommendations need to be individualized to further optimize personal intakes.
Purpose: Dietary nitrate has been shown to enhance muscle contractile function and has, therefore, been linked to increased muscle power and sprint exercise performance. However, the impact of dietary nitrate supplementation on maximal strength, performance and muscular endurance remains to be established. Methods: Fifteen recreationally active males (25 ± 4 y, BMI 24 ± 3 kg/m 2 ) participated in a randomized double-blinded cross-over study comprising two 6-d supplementation periods; 140 mL/d nitrate-rich (BR; 985 mg/d) and nitrate-depleted (PLA; 0.37 mg/d) beetroot juice. Three hours following the last supplement, we assessed countermovement jump (CMJ) performance, maximal strength and power of the upper leg by voluntary isometric (30°and 60°angle) and isokinetic contractions (60, 120, 180 and 300°•s −1 ), and muscular endurance (total workload) by 30 reciprocal isokinetic voluntary contractions at 180°•s −1 . Results: Despite differences in plasma nitrate (BR: 879 ± 239 vs. PLA: 33 ± 13 μmol/L, P < 0.001) and nitrite (BR: 463 ± 217 vs. PLA: 176 ± 50 nmol/L, P < 0.001) concentrations prior to exercise testing, CMJ height (BR: 39.3 ± 6.3 vs. PLA: 39.6 ± 6.3 cm; P = 0.39) and muscular endurance (BR: 3.93 ± 0.69 vs. PLA: 3.90 ± 0.66 kJ; P = 0.74) were not different between treatments. In line, isometric strength (P > 0.50 for both angles) and isokinetic knee extension power (P > 0.33 for all velocities) did not differ between treatments. Isokinetic knee flexion power was significantly higher following BR compared with PLA ingestion at 60°•s −1 (P = 0.001), but not at 120°•s −1 (P = 0.24), 180°•s −1 (P = 0.066), and 300°•s −1 (P = 0.36). Conclusion: Nitrate supplementation does not improve maximal strength, countermovement jump performance and muscular endurance in healthy, active males.
This study investigated the differences in gastrointestinal (GI) and exercise related complaints between groups of runners competing at different distances using web-based questionnaires. Total (severe) complaints were reported by 89.3% (49.7%) of the runners during the race vs. 70.6% (29.4%) after the race. Significant differences between groups were described for marathon (n = 98) and 60 km (n = 43) runners. During competition, runners reported the urge to urinate (47.7%), muscle cramps (43.6%) and belching (43.6%). The prevalence of bloating, flatulence, side ache and dizziness differed between distances (p < 0.02). There were small to moderate negative correlations between food and fluid intake and GI complaints. After competition (12 h), 70.6% of participants reported complaints, with muscle cramps (47.6%), flatulence (19.0%) and bloating (12.7%) being the most prevalent. Prevalence of belching, nausea, stomach cramps and muscle cramps differed between race distances (p < 0.04). There were small to high positive correlations between complaints during and after competition (p < 0.05). In conclusion, runners of all distances reported a high prevalence of GI and other exercise related complaints. There were some small differences in reporting type and severity of complaints between distances. Results showed small to strong correlations between complaints during and after competition and with nutrient intake, without a clear similar pattern for all distances.
Background: A wide range of sports health professionals provide nutritional supplement advice. We aimed to better understand the expertise, knowledge, and attitudes of sports health professionals toward nutritional supplements and third-party supplement testing. Methods: A web-based questionnaire was used to ask questions about nutritional supplement knowledge and attitudes toward the Dutch third-party supplement testing system (NZVT), about supplement efficacy, and if professionals advise these supplements, as well as which profession can be deemed the expert on nutritional supplements. Results: A total of n = 320 sports health professionals delivered input, of which 45% worked with Olympic athletes and 18% were sports dietitians. Sports dietitians were ranked as the most knowledgeable professionals about sports nutrition (80%) and nutritional supplements (74%), and a literature-based comparison showed the most favorable knowledge, attitudes, and ergogenic classifications of supplement scores for sports dietitians compared with other sports health professions. Sports health professionals working with Olympic athletes scored similar but slightly lower trends on self-reported knowledge, attitude and third-party supplement testing than sports dietitians but substantially better than professionals not working with Olympic athletes. Conclusion: Sports dietitians are seen as the absolute expert on supplements by other sports health professionals, with professionals working with Olympic athletes reporting similar trends, and other sports health professionals do have lower self-reported knowledge and preferred attitudes toward effective and safe use of dietary supplements.
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