Build the engine first

Every previous version of this plan was calibrated off a 27:30 5K. That number is out. 7.2 km/h for 20 minutes with heavy breathing is the only current measurement you've given me, and it describes someone with a genuinely low aerobic base right now — not a lapsed 27-minute 5K runner.

7.2 km/h is 8:20 per kilometre. If that's hard, then every pace zone in the last three versions was too fast, the volumes were too high, and following them would have hurt you inside a month. Training at paces you can't sustain doesn't make you tougher. It makes you injured, and then it makes you stop.

So here's the honest picture, and then a plan that actually fits it.

Every pace target is deleted for now. They were derived from a stale time trial and they were all too fast. Until week 12 you have exactly one control: the talk test.

1. Set the belt to 6.5, incline 1%.
2. After five minutes, say a full sentence out loud. Not a word — a sentence.
3. Can't get through it? Drop 0.3 and try again in five minutes.
4. Effortless, could hold it all day? Add 0.3.
5. Whatever number you land on is your easy pace. Write it down. That's the number for the next six weeks.

Most people in your position land somewhere between 6.0 and 7.0. If yours is 6.0, that's fine. If it's 5.8, that's fine too — it just means walking briskly and jogging are close together right now, and that gap widens fast.

Weeks 1–4 are three runs. It goes to four at week 5 and five at week 13. Your lifting keeps both hard upper-body sessions throughout; the leg-day hypertrophy work is what gives way.

Run first, lift second, on shared days.

• Push and pull, merged onto Monday and Wednesday. Weighted dips, weighted pull-ups, loaded push-ups. Chase the +20 kg pull-up — running volume is low enough for months that your upper body barely notices.
• The mobility block. Ankle dorsiflexion especially.
• Core: ab wheel, suitcase carry, Pallof press.

Around 15 minutes, added to Monday and Wednesday, replacing Lower A and Lower B. At your current running volume this is doing more for your injury resistance than the running is.

• Heavy leg press, heavy leg extension, the TRX squat-depth progression. Revisit after week 24.
• Eating in a deficit. Building an aerobic base on low fuel is slow and injury-prone. Maintenance or slightly above.

Two hard tests in six months is deliberate. Testing costs two or three days of recovery, and adaptation is slow enough that measuring monthly gives you noise plus a reason to feel bad on a bad day.

The feedback you want more often is already there: the belt speed that passes your talk test. Same effort, rising speed, week after week. That's your fitness moving, and it costs nothing to read.

• Same treadmill every time. Belts drift out of calibration, so consistency matters more than accuracy.
• Warm up 15 minutes easy plus 4 strides. Cold-starting a time trial costs you 20–30 seconds.
• Even splits. The most common way to ruin one is the first kilometre.
• Two easy days beforehand — that's why it sits on a down week.
• Log the conditions. A bad number on four hours' sleep isn't a plateau.

• August to October: treadmill by default. Controllable pace, forgiving surface, no heat-casualty risk. Incline 0.5–1%.
• Never run outdoors 9am–6pm from June to September. If you go outside it's before 5:30am, with water.
• Feels-like above 32°C, go inside. Heat costs 20–40 seconds per kilometre and wrecks the talk test — you'll be gasping at an effort that's aerobically easy, and you'll misread it as being unfit.
• Hydration: 500–800 ml per hour with 500–1000 mg sodium per litre once runs pass an hour.
• From November, move the long run outside. Treadmill fitness transfers; road durability doesn't, and your half marathon won't be indoors.

Long treadmill runs are mentally brutal. That's not a flaw in the plan — it's the part that builds whatever keeps you moving when it stops being fun. Most people won't do it.

• Under 60 minutes: water. Nothing else needed. That's most of your first three months.
• Over 75 minutes: 30–60 g of carbohydrate per hour, starting around 40 minutes. Begin practising this on the week-13 long runs so race day isn't an experiment.
• Before a long run: 1–2 g carbohydrate per kg bodyweight, two hours out. At 70 kg that's 70–140 g.
• Shoes: rotate two pairs, replace at 600–800 km. Track the mileage — worn midsoles are a genuine injury contributor.
• Sleep: seven to nine hours. It's a training variable, not a lifestyle suggestion, and it's the cheapest one you own.