Eccentric arm cycling: physiological characteristics and potential applications with healthy populations

Eccentric leg cycling has served as an important research model for investigating multi-joint eccentric actions and as an effective rehabilitation and training modality for improving locomotor muscle function (e.g., quadriceps size, strength, mobility). While there are more than 30 reports documenting physiological responses to eccentric leg cycling, physiological responses to eccentric arm cycling (ECarm) have not been clearly established.

We tested the hypothesis that ECarm could be performed with lower levels of metabolic and cardiorespiratory demand and perceived exertion compared to traditional concentric arm cycling (CCarm).

Eight individuals performed ECarm and CCarm at 40, 80, and 120 W (~9 min, 60 rpm) while expired gases and muscle activation patterns were recorded.

Oxygen consumption, cardiac output, heart rate, and ventilation were 25-50 % lower during ECarm compared to CCarm (all P < 0.05). Further, only low-to-moderate levels of whole-body and arm-specific perceived exertion were required to perform ECarm which was not the case for CCarm (8-12 vs. 9-16 Borg values, both P < 0.05). Differences in oxygen consumption and total upper body muscle activity between ECarm and CCarm were strongly related (r (2) = 0.75, P < 0.01). Coordination of ECarm involved triceps brachii, deltoideus anterior, and external oblique muscles, whereas CCarm involved all of these muscles along with contributions from biceps brachii, deltoideus posterior, and trapezius transversalis.

These results highlight the high-force, low-cost nature of multi-joint eccentric actions and extend the application of eccentric cycling to the upper body. ECarm may be useful for exercising elbow, trunk, and shoulder musculature while minimizing metabolic and cardiorespiratory strain and perceived exertion.