If you have trash endurance and want to increase it I would suggest shadow boxing. I did zero cardio for years and after a month of doing 200 punches every morning I was already feeling way better. the difference between doing zero cardio and the bare minimum is enormous.
Shadow boxing is good because you can easily increase the number of punches depending on your endurance, you can have multiple different weights and you can stop whenever you want. If you’re walking for exercise and you feel like quitting, but you’re a mile from home that’s too bad, you have to keep walking. With shadow boxing you can do it in your air conditioned house whenever you have free time.
Aerobic exercise is also a very good treatment for erectile dysfunction, it makes you get harder faster. I wonder if any male porn stars use EPO. If you’re fucking a girl for a 40 minute scene with no breaks that has got to be brutal. A lot of UFC fighters look like they’re dying after a 25 minute fight with 2 minute breaks every 5 minutes. Steroid use is common amongst porn stars, I wonder if they‘re using EPO too.