Moving more without a gym
The usual guidance for adults is about 150 minutes of moderate activity a week, the kind that makes you breathe a little faster, plus something that works the muscles twice a week. That sounds like a lot until it is broken into pieces.
Walking counts
A brisk walk is moderate activity. Thirty minutes on five days covers the week. Get off the bus a stop early, walk to the shops, take a phone call on foot.
Break up the sitting
Long stretches in a chair are worth interrupting even for people who exercise. Stand up and move for two or three minutes every half hour or so: refill a glass of water, take the stairs, stretch.
Strength at home
Muscles need work too, and no equipment is needed: squats to a chair, push-ups against a wall or a table, lunges, a plank. Two short sessions a week make a difference over a few months.
Start where you are
Anything is better than nothing, and the best activity is the one you will keep doing. Add a little at a time, and choose things you enjoy: cycling, dancing, gardening, swimming.
If you have a heart condition, a recent injury or haven't been active for a long time, ask a doctor before starting something strenuous.