Before you start
You'll need your MAF heart rate cap and a way to track it during exercise — a chest strap or wrist-based monitor both work. If you haven't calculated it yet, do that first: everything in this plan is built around staying at or below that specific number, not a pace or distance target.
Find your exact MAF heart rate using the 180 Formula before starting this plan.
MAF Calculator →You'll also want a baseline MAF test before week 1 — a simple time trial (see below) at your MAF heart rate, on a course you can repeat. Without this starting number, you won't have anything to compare your week 4 and week 8 results against.
The 8-week plan at a glance
| Weeks | Sessions/week | Duration/session | MAF test |
|---|---|---|---|
| 1–2 | 3 | 25–35 min | Baseline test before week 1 |
| 3–4 | 3–4 | 35–45 min | Test at end of week 4 |
| 5–6 | 4 | 40–50 min | Test at end of week 6 |
| 7–8 | 4 | 45–60 min | Test at end of week 8 |
Unlike a generic cardio plan, the structure here is built around the testing schedule as much as the training volume — every 2 weeks gives enough time for a genuine adaptation to show up in your numbers, without testing so often that normal day-to-day variation (sleep, stress, weather) muddies the signal.
Weeks 1–2: finding your pace
The goal isn't fitness yet — it's discovering how slow "MAF-slow" actually is for you, and getting comfortable staying there even when it feels too easy or, for a deconditioned aerobic base, surprisingly hard.
Sample week
Monday: 25 min at or below MAF heart rate (walk/run mix if needed)
Wednesday: 30 min, same
Saturday: 35 min, same
Other days: rest or light stretching
Many people are genuinely shocked by how much walking their MAF cap requires in week 1, especially if they've been training primarily by pace or feel rather than heart rate up to this point. This is exactly what an underdeveloped aerobic base looks like — it's the reason the method exists, not a sign it's the wrong approach for you.
Weeks 3–4: extending duration, first real test
Session length increases while frequency holds or ticks up slightly. At the end of week 4, run your second MAF test — the same course, same protocol as your baseline — and compare the time directly.
Sample week
Monday: 35 min
Wednesday: 40 min
Friday: 35 min (add this 4th session if recovery allows)
Saturday: 45 min
Other days: rest
A faster time at the same heart rate here — even a modest one — is the clearest early confirmation that the plan is working. A flat or slightly slower result at week 4 isn't a failure; four weeks is often too early to see the full effect, particularly for anyone starting from a low aerobic base.
Weeks 5–6: consistency, second checkpoint
By this stage the goal shifts from "getting used to the pace" to simply accumulating consistent volume at your MAF cap. Test again at the end of week 6.
Sample week
Monday: 40 min
Tuesday: 40 min
Thursday: 45 min
Saturday: 50 min
Other days: rest or strength training
Weeks 7–8: consolidating the base, final checkpoint
Sessions extend to 45-60 minutes and 4 sessions per week becomes the standard. Run your third MAF test at the end of week 8 and compare it against both your baseline and your week 4 result — a consistent downward trend in time (or upward trend in pace) across all three checkpoints is the strongest evidence the plan is working.
Sample week
Monday: 45 min
Tuesday: 50 min
Thursday: 50 min
Saturday: 60 min (long session)
Other days: rest or strength training
Compare MAF training to a standard Zone 2 approach to decide which fits your goals.
Zone 2 vs MAF Training →Reading your MAF test results
Three checkpoints (baseline, week 4, week 8) give you a trend line, which matters more than any single number. A single flat or slightly slower test can simply reflect a bad night's sleep, heat, or an off day — it's the direction across multiple tests that tells you whether the aerobic base is actually developing.
- Consistent improvement each test: the plan is working as intended — continue building volume or extend to a second 8-week block.
- Improvement at week 4, plateau by week 8: common, and often means it's a reasonable point to hold volume steady for a few more weeks rather than continuing to add duration.
- No improvement across any test: double-check you're genuinely staying at or below your MAF cap during sessions (a monitor reading a few beats high consistently can hide real progress) and that sessions are actually happening 3-4 times a week, not less.
If you fall behind
Missing a single session isn't a problem — continue the week's schedule as planned. If you miss a full week, pick back up at the same phase rather than repeating it. If you miss 3 or more consecutive weeks, drop back to the start of the previous phase, since aerobic adaptations fade measurably after a month without stimulus.
Common mistakes in a MAF plan
- Drifting above the heart rate cap to "feel like you're training." This is the single most common way people accidentally turn MAF training into regular easy running, which defeats the purpose.
- Testing on different courses each time. Makes your data noisy enough that real progress can be invisible — pick one course and stick with it for all three checkpoints.
- Quitting after a disappointing week 4 test. Four weeks is genuinely too short for some people, especially those starting from a very low aerobic base — the week 8 test is often where the trend becomes clear.
- Adding speed work too early. Introducing harder sessions before week 8 dilutes the aerobic stimulus the plan is built around and makes your MAF test results harder to interpret.