The exercise profile of an ultra-long handcycling race: the Styrkeprøven experience.

BACKGROUND: The high mechanical efficiency of the geared handcycle makes it suitable for elite athletes to train and even compete in races with able-bodied (recreational) cyclists. However, the actual exercise profile for endurance events has not been quantified. OBJECTIVE: To guide future training regimes in a safe and effective process, the aim of this research was to quantify the workload, speed, cadence and heart rate parameters during 6000 km of training and within a 540 km ultra-long races. METHODS: One spinal cord injured participant (lesion level Th4, ASIA B) handcycle (modified Shark S Sopur--Sunrisemedical, Malsch, Germany) was equipped with Schoberer Bike Measurement System (SRM) crank. For the laboratory test, a Cyclus II Ergometer was used. The energy intake and quality was determined during the time of race (540 km). RESULTS: Workload at a defined metabolic situation was augmented through training by 63.8% from 90.0 to 147.6 W. The athlete finished the 540 km race with an average speed of 21.6 km h⁻¹ and a total race time of 38:52 h. CONCLUSIONS: Ultra-long-term races in a handcycle can be suited by well-trained persons with a spinal cord injury. The quality of the training preparation time (for example, intensity and volume) is of immense importance to reach an adequate physiological capacity and to avoid serious injuries or medical problems.

Impact of exercise on neuroplasticity-related proteins in spinal cord injured humans.

The present study investigated the effects of exercise on the serum concentrations of brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), prolactin (PRL) and cortisol (COR) in 11 chronically spinal cord-injured athletes. In these subjects BDNF concentration at rest was sixfold higher compared with the concentrations reported earlier in able-bodied persons, while IGF-1, PRL and COR were within normal range. Ten minutes of moderate intensity handbiking (54% of the maximal heart rate) during a warm-up period (W) induced an increase (P<0.05) of BDNF of approximately 1.5-fold from basal level at rest, while a decrease to basal level was found after an immediately succeeding handbiking time trial (89% of the maximal heart rate) over the marathon distance of 42 km (M). An increase (P<0.01) of serum IGF-1 was found after W and this levels remained elevated (P<0.01) until the end of M. W had no significant effects on the serum PRL and COR, however, M induced an increase (P<0.01) of both hormones. This is the first study showing elevated BDNF concentrations at rest in spinal cord-injured athletes. Furthermore, short moderate intensity handbiking but not immediately following long lasting high intensity handbiking further increases serum BDNF concentrations. IGF-1 response to exercise differs to BDNF response as this neuroplasticity-related protein remains elevated during the long lasting physical demand with high intensity. The augmented PRL concentration suggests that a possible mechanism by which exercise promotes neuroplasticity might be the activation of neural serotonergic pathways as 5-HT is the main PRL releasing factor. Elevated COR concentrations after M are unlikely to be deleterious to neuroplasticity as COR concentrations remain within the physiological range. The present study suggests that exercise might be beneficial to enhance neuroprotection and neuroplasticity, thereby improving recovery after spinal cord injury.