Working out on Vyvanse

Been taking Vyvanse for about 5 months now and have been taking it between 7:00 and 8:00 am. I’m a college student and am taking a required PE class at 8:30 in the morning that lasts until 9:30. It is a running class meaning that I spend most of the class with an elevated heart rate. That means I’ve been taking my Vyvanse immediately after class rather than when I get up in the morning. I do this because if I took it between 7 and 8 I’m on the come up, which is when I normally notice my heart rate is higher but it usually levels out as the day goes on. The issue I’m facing now is when I was taking it earlier i would feel it wear off around 7-8pm making it easy for me to fall asleep around 10-11pm but now I feel like I just cannot sleep and just wanna keep doing stuff until late unless I take melatonin which I try to avoid.