Most people who "got out of shape" did not fail because they lack discipline. They failed because the plan assumed a gym, a commute, and 60 free minutes.

That plan dies the first week work runs late.

If you only have 15 minutes or even less at home, treat that as the real constraint — not a lesser version of "proper" training.

What actually works for busy adults

• Same time, same room, every day. Identity beats motivation.

• A session you can start in under 60 seconds. Mat down. Timer on.

• Full-body, no equipment to start. Squats, push-ups, hinges, a carry or a plank.

• Stop when the 15 minutes are done. Extra work is how people quit.

The people who get back in shape are not the ones who wait for a perfect 6-week block. They are the ones who keep a 15-minute floor on the worst days.

If you missed last month, start with today's 15. That is the whole move.