Interrelations between power, force production and energy metabolism in maximal leg work using a modified rowing ergometer

The dependence of power on aerobic and anaerobic energy metabolism and on force production was studied in maximal leg exercise. National and international level male rowers (n = 9) performed four modified (legs‐only) rowing ergometer exercises: a progressive test, 2‐min (T2), 12‐min (T12) and 6‐min (T6) all‐out tests. In T2, significant correlations were observed between power in T2 (P_T2) and oxygen debt (r = 0.83, P<0.05) and between P_T2 and average force production (F_av) during the last 30 s (r = 0.85, P<0.05). These parameters explained 93% of the variation in P_T2. The highest correlations between power in T6 (P_T6) and physiological parameters were as follows: maximal oxygen uptake (VO₂ max: r = 0.87, P<0.01), blood bicarbonate concentration before the test ([HCO^‐ _3before]: r=0.85, P<0.05) and blood lactate concentration on anaerobic threshold (BL_anT: r= —0.82, P<0.05). Together, these parameters explained 92% of the variation in P_T6. In T12, the total power (P_T12) correlated with power of anaerobic threshold #OPP_ANT’. r = 0.95, P< 0.001) and with the highest VO₂ value in this test (VO₂ peak: r = 0.92, P<0.001). These two parameters explained 96% of the variation in P_T12.

The decrease of at least one of the force parameters during each test was taken as a sign of fatigue. The decline in force was compensated for by an increase in stroke rate at the end of T6 and T12 (P<0.01, P<0.001). Consequently, the power remained unchanged or even increased at the end of T6 and T12. The term ‘power endurance’ is introduced to describe the ability to resist and to compensate for local muscular fatigue.

Keywords:

• Power
• force
• energy metabolism
• fatigue
• power endurance
• rowing

Notes

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