Spinal Cord Injury Level Influences Acute Plasma Caffeine Responses.

PURPOSE: This study aimed to investigate the absorption curve and acute effects of caffeine at rest in individuals with no spinal cord injury (SCI), paraplegia (PARA), and tetraplegia (TETRA). METHODS: Twenty-four healthy males (eight able-bodied [AB], eight PARA, and eight TETRA) consumed 3 mg·kg caffeine anhydrous (CAF) in a fasted state. Plasma caffeine [CAF], glucose, lactate, free fatty acid, and catecholamine concentrations were measured during a 150-min rest period. RESULTS: Peak [CAF] was greater in TETRA (21.5 µM) compared with AB (12.2 µM) and PARA (15.1 µM), and mean peak [CAF] occurred at 70, 80, and 80 min, respectively. Moderate and large effect sizes were revealed for TETRA compared with PARA and AB (-0.55 and -1.14, respectively) for the total area under the [CAF] versus time curve. Large interindividual responses were apparent in SCI groups. The change in plasma catecholamine concentrations after CAF did not reach significance (P > 0.05); however, both adrenaline and noradrenaline concentrations were lowest in TETRA. Significant increases in free fatty acid were seen over time (P < 0.0005), but there was no significant influence of SCI level. Blood lactate concentration reduced over time (P = 0.022), whereas blood glucose concentration decreased modestly (P = 0.695), and no difference between groups was seen (P > 0.05). CONCLUSION: The level of SCI influenced the caffeine absorption curve, and there was large interindividual variation within and between groups. Individual curves should be considered when using caffeine as an ergogenic aid in athletes with an SCI. The results indicate TETRA should trial low doses in training and PARA may consider consuming caffeine greater than 60 min before exercise performance. The study also supports caffeine's direct effect on adipose tissue, which is not secondary to catecholamine release.

Nutritional Supplement Habits of Athletes With an Impairment and Their Sources of Information.

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.