Described herein are methods for determining a target musculoskeletal activity cycle (MSKC) to cardiac cycle (CC) timing relationship. The method may include detecting a first characteristic of a signal responsive to a CC timing of a user that repeats at a frequency that corresponds to a heart rate of the user； detecting a second characteristic of a signal responsive to a rhythmic musculoskeletal cycle activity (MSKC) timing of the user that repeats at a frequency that corresponds to the MSKC rate of the user； determining a value representative of an actual timing relationship between the first characteristic and the second characteristic； detecting a third characteristic of a signal corresponding to a physiological metric that varies with the actual timing relationship between the first and second characteristics； and determining a target value representative of a preferred timing relationship between the first and second characteristics.
