The aim of this study was to investigate whether caffeine and/or sodium citrate have an ergogenic effect on the 1,500-m exercise performance in elite wheelchair athletes. A placebo-controlled, randomized, cross-over and double-blind study design was conducted with the four treatments placebo, caffeine, sodium citrate and the combination of caffeine and sodium citrate. Nine healthy, elite wheelchair-racing athletes (median: [min; max] age: 28 y [23; 54]; height: 173 cm [165; 188]; weight: 62.9 kg [48.9; 68.4], category T53/54) completed the study. All athletes were national team members, including several Paralympic Games, World and European Championship medalists. The athletes performed a 1,500-m time trial four times on a wheelchair training roller. Time to complete 1,500-m, pH, bicarbonate and sodium concentration as well as lactate concentration were measured. The time to complete 1,500-m was not significantly different between the four treatments (placebo: 170.6 s [141.7; 232.0]; caffeine: 179.5 s [134.8; 239.6]; sodium citrate: 178.3 s [136.4; 247.1]; combination: 177.6 s [136.1; 256.2]). However, pH and bicarbonate concentrations were significantly increased with sodium citrate ingestion compared with placebo. Moreover, maximal lactate concentrations were significantly higher in the caffeine and the combination treatment compared with placebo. The supplementation with sodium citrate and/or caffeine did not provide an ergogenic effect on the 1,500-m exercise performance in wheelchair elite athletes.
Joelle Leonie Flueck, Samuel Mettler and Claudio Perret
Terri Graham-Paulson, Claudio Perret and Victoria Goosey-Tolfrey
Caffeine’s (CAF) ability to influence upper-body exercise endurance performance may be related to an individual’s training status. This case study therefore aimed to investigate the ergogenic effects of CAF dose on 20-km time trial (TT) performance of an elite male paratriathlete (wheelchair user; age = 46 years, body mass = 76.9 kg, body fat = 25.4%, and handcycling
Terri S. Graham-Paulson, Claudio Perret, Phil Watson and Victoria L. Goosey-Tolfrey
Caffeine can be beneficial during endurance and repeated-sprint exercise in able-bodied individuals performing leg or wholebody exercise. However, little evidence exists regarding its effects during upper-body exercise. This study therefore aimed to investigate the effects of caffeine on sprint (SPR) and 4-min maximal-push (PUSH) performance in wheelchair sportsmen.
Using a double-blind, placebo-controlled, crossover design, 12 male wheelchair rugby players (age 30.0 ± 7.7 y, body mass 69.6 ± 15.3 kg, training 11.1 ± 3.5 h/wk) completed 2 exercise trials, separated by 7–14 d, 70 min after ingestion of 4 mg/kg caffeine (CAF) or dextrose placebo (PLA). Each trial consisted of four 4-min PUSHes and 3 sets of 3 × 20-m SPRs, each separated by 4 min rest. Participants responded to the Felt Arousal (a measure of perceived arousal), Feeling (a measure of the affective dimension of pleasure/displeasure), and rating-of-perceived-exertion (RPE) scales. Salivary caffeine secretion rates were measured.
Average SPR times were faster during CAF than PLA during SPR 1 and SPR 2 (P = .037 and .016). There was no influence of supplementation on PUSHes 2–4 (P > .099); however, participants pushed significantly farther during PUSH 1 after CAF than after PLA (mean ± SD 677 ± 107 and 653 ± 118 m, P = .047). There was no influence of CAF on arousal or RPE scores (P > .132). Feeling scores improved over the course of the CAF trial only (P = .017) but did not significantly differ between trials (P > .167). Pre-warm-up (45 min postingestion) salivary CAF secretion rates were 1.05 ± 0.94 and 0.08 ± 0.05 μg/min for CAF and PLA, respectively.
Acute CAF supplementation can improve both 20-m-sprint performance and a 1-off bout of short-term endurance performance in wheelchair sportsmen.
Terri Susan Graham-Paulson, Claudio Perret, Brett Smith, Jeanette Crosland and Victoria Louise Goosey-Tolfrey
The consumption of nutritional supplements (NS) is common among able-bodied (AB) athletes yet little is known about NS use by athletes with an impairment. This study examined the: (i) prevalence of NS use by athletes with an impairment; (ii) reasons for use/nonuse; (iii) sources of information regarding NS; and (iv) whether age, gender, impairment, performance level and sport category influence NS use. The questionnaire was completed by 399 elite (n = 255) and nonelite (n = 144) athletes (296 M, 103 F) online or at a sporting event/training camp. Data were evaluated using chi-square analyses. Fifty-eight percent (n = 232) of athletes used NS in the previous 6-month period and 41% (n = 102) of these followed the instructions on the label to determine dose. Adherence to these AB recommendations may partly explain why 9% (n = 37) experienced negative effects from NS use. As expected, the most popular NS were: protein, sports drinks, multivitamins and carbohydrate supplements, which were obtained from health food/sport shops, internet and supermarkets (top 3) where evidence-based, impairment-specific advice is limited. The nutritionist/dietitian was the most used and trusted source of information, which is a promising finding. The most prevalent reasons for use were to support exercise recovery, support the immune system and provide energy. Elite athletes were more likely to use NS, which may reflect greater training hours and/or access to nutritionists. Fifty-two percent of athletes (n = 209) requested more information/education regarding NS. NS use is prevalent in this population. Education on dosage and appropriate sources of information is required.
Joelle Leonie Flueck, Martina Lienert, Fabienne Schaufelberger, Jörg Krebs and Claudio Perret
The aim of our study was to investigate the effect of caffeine supplementation on 3-min all-out arm crank exercise performance in paraplegic (P) and tetraplegic (T) compared with able-bodied (AB) participants. A placebo-controlled, randomized, crossover, and double-blind study design was chosen to investigate the differences between caffeine (CAF) and placebo (PLC). In total, 34 healthy, trained participants were tested. Seventeen were AB (median [minimum; maximum] VO2peak: 33.9 mL/min/kg [23.6; 57.6]), 10 were P (VO2peak: 34.4 mL/min/kg [19.5; 48.8]), and 7 were T (VO2peak: 13.6 mL/min/kg [8.6; 16.3]). All participants performed two 3-min all-out tests on an arm crank ergometer following the ingestion of either PLC or CAF. Power output parameters, plasma caffeine (PC), epinephrine (EPI), and norepinephrine (NOR) concentrations were assessed. CAF significantly increased average power over the first 30 s (p = .028) and 60 s (p = .005) in P, but not in T (p = .61; p = .87) nor in AB (p = .25; p = .44). Peak power was increased in the CAF trial in AB (+46 W) as well as in P (+21 W) but was not significantly different from PLC (AB: p = .10; P: p = .17). PC significantly increased in all groups (AB: p = .002; P: p = .005; T: p = .018) whereas EPI showed a significant increase only in AB (p = .002) and in P (p = .018). NOR increased significantly in AB (p = .018) but did not increase in the other groups. Caffeine seems to enhance short-duration exercise performance in P. In contrast, T showed a high interindividual variability and overall no ergogenic effect was detected in this group.