Preexercise ingestion of a high-sodium beverage increased plasma volume before exercise and involved less thermoregulatory and perceived strain during exercise and increased exercise capacity in warm conditions.

Study design: Cross-sectional analyses. Objectives: To analyze exercise intensity during a mountain time trial in handcycling and to determine predictors of race time. Setting: Eight Dutch rehabilitation centers and Austrian mountain. Methods: Forty participants with spinal cord injury (SCI; high lesion level (4T6): N ¼ 11; low lesion level (pT6): N ¼ 29) handcycled a 20.2-km mountain time trial. Heart rate (HR) was monitored in 17 (high: N ¼ 5, low: N ¼ 12) participants during the race to determine exercise intensity, expressed relative to the heart rate reserve (%HRR). Two weeks before the race all participants completed laboratory tests to measure anthropometrics and peak values for power output (POpeak), oxygen uptake (VO2peak) and HR. Results: Mean race time was 4 h and 1 min (s.d.: 1 h and 24 min), with no difference in race time between lesion groups. Mean exercise intensity during the race was 70 ± 7%HRR. Exercise was mainly (73% of the race time) at a vigorous intensity (60-89%HRR), with 29% of the total time in the 80-89%HRR zone. No clear differences were found in exercise intensities between lesion groups. The strongest predictors for better race times were higher mean %HRR during race (R 2 ¼ 57%), lower waist circumference (R 2 ¼ 39%), higher POpeak (R 2 ¼ 39%) and VO2peak (R 2 ¼ 32%). Conclusion: A 20-km mountain time trial in a handcycle is intensive. Faster race times were achieved by those with a lower waist circumference, greater fitness level and ability to perform at higher average exercise intensities during the race. Level of SCI was not significantly associated with race time.

Venous occlusion strain gauge plethysmography (VOP) is based on the assumption that the veins are occluded and arterial inflow is undisturbed by the venous cuff pressure. Literature is not clear concerning the pressure that should be used. The purpose of this study was to determine the optimal venous occlusion pressure at which the highest arterial inflow is achieved in the forearm, calf, and leg by using VOP. We hypothesized that, for each limb segment, an optimal (range of) venous cuff pressure can be determined. Arterial inflow in each limb segment was measured in nine healthy individuals by VOP by using pressures ranging from 10 mmHg up to diastolic blood pressure. Arterial inflows were similar at cuff pressures between 30 and 60 mmHg for the forearm, leg, and calf. Arterial inflow in the forearm was significantly lower at 10 mmHg compared with the other cuff pressures. In addition, arterial inflows at 20 mmHg tended to be lower in each limb segment than flow at higher cuff pressures. In conclusion, no single optimum venous cuff pressure, at which a highest arterial inflow is achieved, exists, but rather a range of optimum cuff pressures leading to a similar arterial inflow. Venous cuff pressures ranging from 30 mmHg up to diastolic blood pressure are recommended to measure arterial inflow by VOP.

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