Exercise bike after 70: how long, how often, what resistance

The bike is in the corner of the room, and the question is always the same: how long to ride, how many times a week, and how much resistance to dial in so it counts as training rather than spinning your legs for nothing. After 70 the answers shift a little — not because you can do less, but because recovery takes longer and because riding on almost no resistance is the mistake nearly everyone makes. Here are the numbers worth starting from, and how to raise them without overdoing it.

How many minutes per ride

General guidance for adults settles at around 150 minutes of moderate aerobic activity a week, and that does not stop applying in your seventies. But it is a target for a few months from now, not for week one.

If you have not ridden in a while, start at 10 to 15 minutes in total, warm-up included. Once that passes without knee soreness and without leaving you badly out of breath, add 2 to 3 minutes a week.

A sensible ceiling is 25 to 40 minutes of continuous riding. Past 45 minutes the benefit climbs slowly while the odds of a niggling joint and of sheer boredom climb fast.

Splitting the ride is fine. Two lots of 15 minutes, one in the morning and one in the afternoon, count the same as a single 30-minute session, and plenty of people find that far easier to sustain.

How often each week

Three rides a week is the floor at which progress actually shows. Four to five is where endurance changes noticeably.

Three ways to reach a similar weekly total:

• five rides of 30 minutes at a moderate effort
• three rides of 50 minutes, if fewer trips to the bike suits you better
• four rides of 25 minutes plus two brisk 25-minute walks

Leave at least one day a week clear of the bike entirely. And do not expect the bike to cover everything: two sessions of leg and trunk strength work a week still matter, because the muscle loss that comes with age carries on regardless of how good your aerobic fitness looks.

Resistance: the part most people get wrong

The typical scene: resistance on level one, legs whirring round, twenty minutes gone, and the muscles never noticed they were working. Fast pedalling against nothing gives you very little.

Aim for 55 to 70 revolutions per minute — most displays call this RPM or cadence — and set the resistance so the effort sits at 4 to 6 on a scale of 1 to 10.

In plain terms: at 4 to 6 you can speak in full sentences but you could not sing. If you can hold a conversation without pausing for breath, the resistance is too low. If you cannot finish a sentence, it is too high.

Progress by resistance, not by speed. When 30 minutes at an effort of 3 out of 10 feels easy, put the resistance up one level and keep the same cadence. On a stationary bike, that is what real progress looks like.

Heart rate is a weaker guide than most people assume. The old "220 minus your age" sum is a rough estimate with a wide spread around it, and blood pressure and heart medicines hold many people's heart rate down no matter how hard they work. Perceived effort and the talk test are more reliable.

If the display shows watts, 40 to 70 W is a common starting range, though it varies a lot between people and between machines. Use the figure to track yourself over months, not to compare yourself with anyone else.

Setting the bike up

Stand beside the bike and set the saddle roughly level with your hip bone. At the lowest point of the pedal stroke the knee should stay slightly bent, never locked straight.

A saddle set too high makes the hips rock side to side. Too low and the load shifts onto the front of the knee. If you get pain at the front of the knee when it bends under load, check saddle height before you write the bike off.

Raise the handlebars enough to keep the spine upright and the shoulders loose. A recumbent bike makes sense if climbing onto an upright feels unsteady, if your lower back complains, or if your balance is not what it was.

Wear shoes with a firm sole and tighten the pedal straps. Slippers and bare feet are the usual reason a foot slips off mid-ride.

A six-week plan

1. Weeks 1–2: three rides a week — 5 minutes warming up on light resistance, 8 minutes at an effort of 3–4 out of 10, 3 minutes easy to finish.
2. Weeks 3–4: four rides — 5 minutes warm-up, 12 to 15 minutes at 4–5 out of 10, 3 minutes cooling down.
3. Weeks 5–6: four to five rides — 5 minutes warm-up, 20 to 25 minutes at 4–5 out of 10, 3 minutes cooling down. Once a week, add five intervals: 1 minute at 6 out of 10, then 2 minutes very easy.

One rule for adding load: if you are more tired the day after a ride than you were before it, add nothing that week. Repeat the same dose and move on only when it feels comfortable.

If you are coming back from pneumonia, surgery or a long spell in bed, halve every number above — returning to training after illness follows its own timetable and punishes impatience.

What the bike will not do for you

Pedalling puts no load through the skeleton. You are seated, your weight is on the saddle, so the bike gives bones nothing like what walking and stairs give them. If bone density is a concern, pair it with regular stair work a few times a week.

It does not train balance either, since at no point do you have to hold your body over your feet. That has to come from upright work on the floor.

And it builds endurance in the quadriceps rather than the strength you need to stand up from a low chair without pushing off with your hands. For that you need resistance work, twice a week, 2 to 3 sets per exercise.

When to see a doctor

Stop riding and get medical advice if you feel pressure or tightness in the chest, neck or jaw, breathlessness out of proportion to the effort, dizziness or faintness, a suddenly irregular pulse, or new pain and swelling in a calf.

Get checked before you start if your blood pressure is uncontrolled, if you have had a recent cardiac event or a recently fitted heart device, or if effort has brought on chest pain in the past.

Knee or hip pain that lasts more than 48 hours after a ride, or a joint that swells, is a reason to be seen — not a reason to push through.

The short version

• Start at 10–15 minutes per ride and add 2–3 minutes a week; 25–40 minutes is a realistic target.
• Three rides a week is the minimum, four to five gives the best return; roughly 150 minutes a week is the wider goal.
• Hold 55–70 revolutions per minute at a resistance that puts the effort at 4–6 out of 10 — able to talk, not to sing.
• Progress by raising resistance, not pedal speed; heart rate is a poor guide if you take heart or blood pressure medication.
• Saddle level with your hip, knee slightly bent at the bottom of the stroke; add walking and two strength sessions a week alongside the bike.