In the absence of a timekeeping device, the passage of time has to be estimated by the person experiencing it. Time is perceived to pass at different rates under different conditions. For example, time seems to pass at a faster rate when attention is occupied (time flies when you are having fun), but at a slower rate in times of emotional or physical distress. Time estimation is important in sports and during exercise because misjudging how time passes could affect performance. This study is being done to investigate how people of high and low fitness levels experience the passage of time during exercise on different forms of activity. I will also investigate if using a different mode of exercise has an impact on the subjective experience of time.