Low-Impact Cardio

Five sessions a week on a bike, a rower, a cross-trainer and a stair climber, none of which loads a joint through an impact.

Four of them are easy, continuous work at a pace where you can hold a conversation; the fifth is fifteen minutes of hard climbing in three-minute pieces with equal recovery.

Every session has a warm-up ramp and a cool-down built into it, and the intervals are preceded by three rising build-up efforts so nothing hard ever starts cold. Before you start, please read this one.

Aerobic exercise is among the safest and most useful things most people can do for their health, and it is also the setting in which a heart problem nobody knew about is most likely to announce itself.

Get medical clearance before you begin if any of the following is true of you. Chest pain, pressure or tightness on exertion, including anything that comes on when you hurry, climb stairs or carry shopping and eases when you stop.

Dizziness, light-headedness or fainting, on effort or when you stand up. Known heart disease, a heart-rhythm problem, or a heart attack, stent, bypass, ablation or any cardiac procedure at any point in your life.

Or no regular exercise for a year or more, if you are also over 40, or you smoke, or you have high blood pressure, high cholesterol or diabetes, or a parent or sibling who had heart disease before 55 in men or 65 in women.

Any of those means speak to your GP before you start, and follow what they tell you over anything written here. Which one applies changes what to do while you wait.

If it is the last one — no regular exercise for a year or more alongside those risk factors — then this is one of the two programmes to be on in the meantime, leaving out day four, which is the interval day, until you have been cleared.

If it is chest pain on exertion, dizziness or fainting on effort, or known heart disease or a cardiac procedure, do not start this or anything else here until you have been seen.

Those three are the ones where waiting is the instruction rather than walking. The other four days are easy machine work at a pace where you can talk in full sentences.

Also speak to your GP or a physiotherapist first if you are pregnant or within a year of giving birth, if your blood pressure or diabetes is not currently controlled, if you have low bone density or osteoporosis, if you have a lung condition, or if a joint or tendon is flaring.

Stop the session and get medical advice the same day for chest pain, pressure or tightness; pain spreading into the jaw, neck, back or an arm; breathlessness far out of proportion to the effort; dizziness or feeling you might faint; a heartbeat that is unusually fast, slow or irregular; or a cold sweat with any of those.

Call emergency services rather than driving yourself. Nothing here is medical advice.