Fig. 3
The accuracy (mean bias) and precision (±1.96 Standard deviation (SD)) of the VO2peak prediction algorithms for the lower (panel a) and the upper (panel b) position of the smartphone placement in the ‘leave-on-out cross validation’. The dotted line is the best fit line and represents the bias of the predicted values. Triangles (▲) represent the predicted values from the VM derived from the smartphone when placed in the upper position and crosses (X) are predicted values from the lower position