I’ve been doing 100 pushups a day, 6 days/week (1 rest day on Sunday) for about 3 months now.
Before I used to get back aches and had an awful form. Now I feel great. After having a kid, it has been hard to find time to go to the gym. Two sets of pushups, one in morning, and one in evening is easy to get in. Takes 5 mins and you feel pumped.
Also been having more sex. So that’s been a great for health too.