During incremental exercise, how is cardiac output able to continually increase even though stroke volume plateau around 40-60% vo2 max

Theres a cure in it but if you get a higher percentage then theres definingly something wrong with you. Try talking to your doctors about this question.

Explanation:

you may having too much sleep.. a good night sleep consists of about 7 hours. more than that could be the reason you're still tired throughout the day.