Physiological, biochemical and mechanical issues relating to resistive force selection during high-intensity cycle ergometer exercise

High-intensity cycle ergometry of 30 seconds duration has been widely employed to assess indices of muscle performance during maximal exercise. Traditionally, the resistive force established for such a test is determined from total body mass (TBM) for a friction-loaded Monark cycle ergometer, i.e. 75 g·kg−1. More recent studies have shown that traditional forces may be too light to elicit maximal performances and that optimization protocols can produce higher peak power outputs. Conceptually, selecting the optimal resistive force according to TBM may not be the best approach. Fat-free mass or active muscle tissue may be a more preferable alternative. Because body mass, and not composition, is the most commonly used index to determine cycle ergometer resistive force, over-or underestimations in power calculations may occur. The aim of this paper is to outline friction-loaded cycle ergometer performance using resistive forces derived from TBM and fat-free mass, to quantify the upper body contribution to high-intensity cycle ergometry. A further aim is to outline mechanical issues related to cycle ergometer design and to quantify discrepancies in resistive force application.