Getting back into exercise after a break: start light, go far.

Getting back into exercise after a long break, months or years, usually starts the same way. You put your trainers in the gym bag, open your phone notes and find your old weights. You load those and it goes well.

Two days later you're coming downstairs sideways. In week two an elbow or knee complains, and the bag goes back in the cupboard. I often see it after years at a desk. Your body usually comes back sooner than you'd think if the first month asks little of it.

The signs that tell you to ease off

• Your legs, two days later. Stairs and chairs are still a struggle midweek.
• One precise spot. Elbow, knee, shoulder: a niggle in the joint, unlike a tired muscle.
• The next session. You lift less than last time.

What comes back fast and what takes time

Muscle remembers. If you've trained before, most of the muscle you lost usually returns in six to eight weeks. The movement stays too: the pathways between brain and muscle that practice opened are still there. Think of skiing again after years away: stiff first runs, then it all comes back.

Tendons move at their own pace. They get little blood, so they adapt more slowly than muscle. The week-two setback can start here: your muscles are ready to load up, your tendons and joints need longer.

Soreness keeps its own hours. It usually shows up after eight to ten hours, peaks one to two days later, sometimes three, and can last almost a week. Lactic acid has little to do with it: your body clears that within hours. Most of it comes from braking the weight on the way down.

How do you get back into training after years off?

With two sessions a week, light weights and four weeks of small increases. Tendons and joints set the pace.

Start with a weight that feels too light. One you can lift for ten to sixteen clean reps with four or five left in you. That's roughly 60 to 70 per cent of the most you could lift once today. No need to test it. Just count. Stay there three to four weeks.

Two sessions, forty-eight hours apart. How to build them is in the article on having no time to exercise. That one starts at ten reps; here it's a few more, with less weight. Five days a week straight away usually ends in another break.

Change one thing at a time. Technique first, then load, then sets, frequency last. In the first month you stay between sixteen and ten reps, fewer as the weight goes up.

Warm up in steps. A few minutes of easy movement, then the same exercise with the weight rising to the day's load.

Read the soreness, without chasing it. A little is normal. If sitting down is still hard after three days, drop a set next time. If the pain is in a joint, or comes on suddenly mid-movement, take weight off and see a doctor if it stays.

For your fitness, start by walking. Heart and lungs want a base before any sprints: low intensity, short stretches, long recoveries.

Pack your gym bag tonight. Leave the first session feeling you could have done more. In the first month, that's the right sign.