https://pubmed.ncbi.nlm.nih.gov/40419564/
Researchers found that while any exercise is beneficial, morning exercise (6–8 AM) acts as a powerful "circadian anchor." It significantly advances the body's internal clock (earlier melatonin onset), helping participants fall asleep faster and wake up more easily. In contrast, evening exercise (6–8 PM) was found to be more effective for cardiovascular metrics, specifically improving blood flow and lowering systolic blood pressure. As someone who exercises in the morning I’m biased. I’m guessing long-term morning exercise improved cardiovascular metrics enough for the difference to be negligible. Would you expect inadequate sleep to negate those cardiovascular benefits down the road and cause more heart issues?
Andrew Huberman talks about working out at night time https://www.instagram.com/reel/DUOKKb-jjYb/?igsh=NTc4MTIwNjQ2YQ==