Ou have a 44-year old male client with a resting heart rate of 68 bpm. if using the heart rate reserve method (karvonen formula), what would be his optimal training intensity range for aerobic exercise aimed at cardiorespiratory improvements?

The intensity range would be 60-80%.

A high resting heart rate is indicative of an inefficient heart or possible arrhythmia. Physical activity assessments should begin after the client has been screened and resting measurements have been assessed.  Moderate intensity exercise uses energy 3 - 6 times that of resting metabolism, which equates to 3 -6 METs. 

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.