Declan's 12-Week Couch-to-5K

The formula: 220 − 54 gives a nominal maximum of 166 bpm, so a typical 60–70% band would be about 100–116 bpm. Two things make that misleading.

1. The formula itself is imprecise. The error is roughly ±10–12 bpm, so his true maximum could be anywhere from about 145 to 190. Training to a number derived from it is guesswork dressed up as science.
2. Bisoprolol changes the picture. A beta-blocker slows the heart and blunts the rate response to effort, so at any given workload his heart rate will be lower than predicted. A watch reading a comfortable-looking 108 bpm does not mean he is at 65% - he could be working considerably harder while the number flatters him.

What to use instead

• Talk test (primary): he should be able to speak a full sentence but not sing. If he can only manage a word or two, he is too hard.
• RPE, Borg 6–20: aim for 11–13, 'fairly light' to 'somewhat hard'. Ask him to rate after each interval and record it.
• Recovery: breathing should be back near normal within about a minute of stopping an interval.

Heart rate as trend, not target: once he has three weeks of data, use his own resting HR and the HR at which the talk test fails as personal reference points, and re-set them if his dose changes.

Smartwatch: useful for steps, pace and his own trend line; not a diagnostic tool, and not a reason to train to someone else's formula.

Frequency: three days a week - two supervised group sessions plus one solo walk. Rest days between running days, because at BMI 31 the load through knees and ankles is the limiting factor, not motivation.

Intensity: RPE 11–13, talk test positive. His first month is deliberately easy; the adaptation we want is tendon and habit, not fitness.

Time: week 1, 20–25 minutes of 1 minute jog / 2 minutes walk, repeated; week 2, 1:2 extended to 25–30 minutes; week 3, 2 minutes jog / 2 minutes walk; week 4, 3 minutes jog / 2 minutes walk for 30 minutes. The park loop with benches every 400 m is ideal - the walk breaks are built into the landscape, so nobody feels watched.

Type: walk–jog on flat, traffic-free ground, plus two 10-minute bodyweight strength sessions (sit-to-stand, wall press-ups, calf raises) to protect the joints that will complain later.

Progression rule: increase the jog duration before any increase in pace, and raise total weekly volume by no more than about 10% - if the Saturday session felt harder than RPE 13, repeat the week rather than advance.

Realism of 5 km by week 12: a continuous 5 km is plausible only if he is jogging 3 minutes comfortably by week 4; if not, target a 5 km run/walk in 40–45 minutes and say so early. He should also be nudged toward the 150 minutes a week guideline by walking on non-group days, so he is not dependent on two sessions.

Before he starts

• GP clearance is on file, with the medication recorded; check whether the dose changes in the 12 weeks and re-issue guidance if it does.
• Well-fitted shoes, and a rule that nobody runs in fashion trainers.
• Confidentiality: the group does not need to know what he takes.

During sessions

• Warm-up of brisk walking and dynamic movement, not static stretching.
• Water available at the loop; in warm weather move to early morning and cut volume.
• Because he is on an antihypertensive, watch for light-headedness on standing after he stops - walk it off rather than sitting straight down.
• Cap running at three days a week; offer cycling or swimming as cross-training when his joints are sore, rather than pushing through.

Red flags that stop him immediately - chest pain or pressure, unusual breathlessness, dizziness or fainting, palpitations, or pain that alters his gait. Any of these means stop, sit, and get medical advice; chest pain means call 112/999.

Not a red flag, but a review point: if his RPE for the same session climbs over two weeks, or he is not recovering between sessions, reduce load rather than add a fourth day.