Figure 5.

Connectivity of correlations between stress during the stimulus of interval exercise and the adjustments with training. Network display of the 131 linear relationships between indices of metabolic and mechanical stress during interval exercise and training-induced adjustments (nodes) for Pearson correlations, which passed a threshold of |r| > 0.70 and p < 0.05. Straight red and stippled blue lines, respectively, indicate positive and negative correlations. The strength of the correlation is indicated by the thickness of the lines connecting two nodes. Red and orange colored nodes highlight stress during the first and last session of interval exercise, respectively. Green colored nodes emphasize training-induced fold changes. Note the high connectivity with parameters demonstrating an interaction effect of interval training × the contraction group with the reddish-indicated indices of stress during interval exercise that define (highlighted) entities. This comprises selective correlations of the green-highlighted fold changes in positive peak power and the corresponding rate of force development (black arrows), the fold changes for the AUC of the blood lactate concentration during the ramp test (red arrow) or during interval exercise (green arrow), with the AUC of the perceived exertion, heart rate, the systolic blood pressure, the hemoglobin accruing in m. gastrocnemius, and the oxygen deficit in m. vastus lateralis, and the average power during interval exercise. For the ramp exercise, only the AUCs over the same duration of exercise before training were considered. Abbreviation code: _A, AUC during exercise; BPdia, diastolic blood pressure; BPsys, systolic blood pressure; bm, body mass; DO2, oxygen deficit; DO2_ave, average oxygen deficit; fold, post vs. pre ratio; gas, m. gastrocnemius; glucose, blood glucose concentration; HR, heart rate; _I, during interval exercise; L, _S, number of intervals (sets); left leg; lactate, blood lactate concentration; nPP, negative peak power; nW, negative work; P_ave, average power; post, after training; PPO, peak power output during the ramp test; pPP, positive peak power; pre, prior to training; pW, positive work; rPP, reactive peak power; R, right leg; _R, during ramp test; pRFD, rate of force development during the development of positive peak power; RPE, rate of perceived exertion; sP, target power per PPO; _t, exercise duration; tHb, concentration of total hemoglobin; vas, m. vastus lateralis; tHb_ave, average concentration of total hemoglobin; VO2peak, peak oxygen uptake.