The effects of eccentric arm crank training on upper body performance in elite athletes with a spinal cord injury

Introduction Eccentric strength training is a promising approach to improving upper body strength in athletes, as this type of training has several advantages over training that involves concentric or isometric muscle action (Hoppeler, 2016). Eccentric training shows greater gains in muscle strength and mass with lower cardiovascular and metabolic demands (Douglas et al., 2017; Roig et al., 2009). This, combined with the time-efficient components, makes eccentric training particularly attractive for use in athletes with spinal cord injury (SCI). Despite an increasing number of studies focusing on eccentric training in the lower extremities, little is known about the effects in upper body extremities. Therefore, the main objective of this study was to investigate the feasibility of an eccentric arm-crank training protocol and its effects on upper body performance in elite athletes with SCI. Methods Nine strength training experienced elite athletes (median (Q1-Q3) age 29 (25–35) years) 6 men, 6 (3-10) years active as elite athlete, 12 (10-13) hours of weekly training) with SCI were recruited. The athletes were active in various wheelchair sports including basketball, cycling and athletics. The athletes performed twenty eccentric arm-crank training sessions (2-3 sessions/week for 10-12 weeks), during which intensity (74-182% of predetermined maximal aerobic power) and duration (8-14 min) were progressively increased. The following parameters were assessed before and after the intervention: maximal strength (one repetition maximum (1RM) bench press, grip strength), anaerobic performance (Wingate test), aerobic performance (V̇O2peak-ramp test), arm circumferences. The normal training routine was continued during the study. Results Nine athletes with paraplegia successfully completed the eccentric arm-cranking protocol. The cardiometabolic demands of the training sessions were relatively low at an intensity of 69% (66-76) of maximum heart rate. The athletes improved their maximal aerobic power (+3%, p = 0.047) and increased their arm circumferences (+1-3%, p ≤ 0.027). The further parameters showed no significant improvements, nevertheless most athletes showed individual improvements in all parameters. Discussion/Conclusion Twenty sessions of progressive eccentric arm-cranking, added on top of the normal training routine, improved performance in elite athletes with SCI. The individual improvements found in the athletes are clinically relevant as in this well-trai