Reduced cardiovascular and metabolic responses during eccentric stepping exercise: A pilot study

Abstract This study compared cardiovascular and metabolic responses during concentric and eccentric stepping. Eight participants (5 m, 3f; 22 ± 2 years) performed maximal concentric and eccentric ramp incremental tests on a modified stepping ergometer. Subsequently, three randomized 15‐min constant‐power tests were performed (1) concentric stepping at 90% of the concentric lactate threshold (LT), (2) eccentric stepping at the same power, and (3) eccentric stepping at the same oxygen uptake (V̇O 2 ). At equivalent power (36 ± 6 W, p = 0.62), eccentric stepping resulted in 46 ± 8% lower V̇O 2 , 16 ± 6% lower heart rate (HR), and 11 ± 5% lower mean arterial blood pressure compared to concentric ( p < 0.01). Matching V̇O 2 required 65 ± 19% more power during eccentric stepping ( p < 0.01). During this test, eccentric V̇O 2 and HR continued to increase, resulting in a 22 ± 29% higher V̇O 2 and 19 ± 16% higher HR in the final minute ( p < 0.001). Reduced cardiorespiratory demand during eccentric stepping at the same power as concentric demonstrates a higher eccentric power is required to produce the same V̇O 2 . However, despite being below the concentric LT, eccentric V̇O 2 and HR continued to increase past the predicted steady state, indicating a higher exercise intensity.