I'm really weird when it comes to exercise it seems... Doing intense exercise right before bed gets me into a really relaxed state and I fall asleep quickly. Like, doing push-ups and sit-ups for 10 minutes straight.

I don't run that often anymore, maybe twice a month, but I can only do it in the afternoon or evening. If I go in the morning, I feel very tired so I really have to force myself to keep going, and then after 15-20 minutes, my heart rate settles at close to 190bpm (compared to ~175 in the evening) which to my understanding is way too high for someone in their early 40s.