Fig. 1: ΔCrCEST time-series for volunteer #1, corresponding to the middle slice (5th out of 8 slices). Each row corresponds to different exercise workload. Selected time frames of post-exercise CrCEST time-series are being presented, with frame number written on right top corner of each frame. The temporal resolution was 30s. Though at mild PFE level, the volunteer mostly utilized the lateral gastrocnemius (LG), both LG and medial gastrocnemius (MG) were utilized during intense PFE. As evident visually, the recovery rate increased with increased intensity of exercise levels.

Fig. 2: Panel -1: Time-series of Lactate CEST (LATEST) maps show intense exercise-induced changes in skeletal muscle, using images from 5th slice of volunteer #1. First LATEST frame corresponds to pre-exercise level, whereas the remaining ten frames correspond to ten time points post-exercise with 140s temporal resolution. Panel-2: Time-series plots of LATEST values averaged over the entire lateral gastrocnemius and corresponding fits are shown.