Figure 1.

Power output and muscle oxygen saturation during workload-matched concentric and eccentric type of interval exercise. (A,B) Example of the power output being produced by one subject during one interval of concentric (A) and eccentric (B) interval exercise, respectively, before training. (C–F) Positive and negative work being performed by the left leg of one subject during all intervals of a session of concentric (C) and eccentric (D) interval exercise and the resulting effects on muscle oxygen saturation and hemoglobin concentration in m. vastus lateralis (E,F) for one leg before training.