Parker Hewes - Your Money and Your Health. It was a 20 minute podcast listing 8 ways to maintain your health. It said 20 minutes of vigorous activity a week was enough. I don't do that often apart from my trampoline and I don't do it for 20 minutes at a time. I don't do any heavy lifting either. He did say to eat food a caveman would recognise so it wasn't particularly vegan-friendly.