Cardiovascular changes during maximal incremental exercise in humans are well known. Maximal aerobic power has been used almost exclusively to assess physiological function and to characterise endurance training adaptations. However, because of technological limitations it is not possible to monitor specific cardiac events during maximal exercise. Time and amplitude of the opening and closing of heart valves could provide new insights on the physiological mechanisms during exercise training, detraining, and in the diseased state. Recent technological advances are available where micro-accelerometers can be used to monitor the cardiac cycle. Digital ballistocardiography (dBG) measures the seismic activity of the heart, and acceleration forces during systole and diastole produce very-low-frequency compression waves which can be recorded and matched with the EKG. We hypothesised that dBG could be used to detect these cardiac functional changes in response to maximal exercise. Six male university athletes (Age=20±1.8yrs; Ht=194±4.4cm; Wt=99.7±9.4kg) performed maximal incremental exercise (10 km/h, 2 degree/min incline) on a motor-driven treadmill. Pulmonary gas exchange, heart rate and dBG recordings were monitored at rest, during and immediately following maximal exercise. Paired t-tests were used pre- to post-exercise, with significance reported at p<0.05. Maximal VO2 = 53.3±6.5 mL/kg/min; HR = 193±4bpm, ventilation = 122.6±17.4 L/min, and O2 pulse = 27.6±3.2 mL O2/beat. On average 10 dBG waveforms showed that atrial contraction force increased significantly from 11.9±5.8 mg at rest to 29.4±19.6 mg after exercise, while ventricular contraction force increased from 22.4±12.2 to 53.2±12.7 mg. We also report for the first time during maximal exercise the timing events of the athletic heart (significant changes reported in %): Q-wave to rapid ejection period (-11.8%), Q-wave to aortic valve closure (-30.1%), Q-wave to mitral valve open (-27.4%), Q-wave to early diastole (-27.2%), Q-wave to aortic valve open (-10.5%). Day-to-day reliability for dBG variables is r=0.94. Based on our results, it appears that: (1) dBG has the ability to determine all timing of the cardiac cycle, including the velocity and amplitude of each of these events (atrial contraction, mitral valve open and close, aortic valve open and close, rapid ejection period), and (2) the athletic heart has an individual response to exercise as reflected by the timing changes between subjects. This is the first study to our knowledge that has examined the mechanical changes in cardiac function in varsity athletes after maximal incremental exercise.