Zone 2 training is simple in concept — exercise at 60–70% of your max heart rate — but surprisingly hard to turn into a consistent habit. The pace feels too slow. The sessions feel too easy. Results take weeks to become visible.
This 8-week plan gives you a progressive structure to build from scratch. It works with any exercise — running, cycling, rowing, swimming, hiking — as long as your heart rate is in Zone 2.
Before you start: find your Zone 2
Zone 2 runs from 60% to 70% of your maximum heart rate. Estimate your max heart rate with: 220 minus your age. A 35-year-old's Zone 2 is roughly 111–130 bpm.
Wear a heart rate monitor (Apple Watch works well for this) and check your HR every 5–10 minutes during the session. If you're consistently above the upper limit, slow down — even if that means walking.
The litmus test: you should be able to speak in full sentences. If you can't, you've drifted into Zone 3.
Week 1–2: Foundation
Goal: establish the habit, train your body to recognise Zone 2 pace.
- 3 sessions per week
- 25–35 minutes per session
- HR: strictly 60–70% max. Walk if needed to stay in zone.
- Exercise type: your choice — running, cycling, brisk walking
Don't worry about pace or distance. Heart rate is the only metric that matters. Most beginners will be surprised by how slowly they need to move to stay in Zone 2.
Week 3–4: Volume build
Goal: extend duration, develop fat-burning efficiency.
- 3–4 sessions per week
- 35–50 minutes per session
- HR: 62–70% max
- Add one longer session (50 min) on the weekend if possible
By week 4 you should notice Zone 2 pace increasing slightly — you can move faster while keeping the same heart rate. This is early evidence that mitochondrial adaptations are beginning.
Week 5–6: Consistency
Goal: reach 3+ hours of Zone 2 per week consistently.
- 4 sessions per week
- 45–60 minutes per session
- HR: 63–70% max
- One session can be 75–90 minutes if your schedule allows
This is where the compound effect of Zone 2 starts to become measurable. Your resting heart rate may begin to drop. Your Zone 2 pace at the same heart rate should be meaningfully faster than in week 1.
Week 7–8: Tempo integration
Goal: maintain Zone 2 base while introducing one quality session per week.
- 4 sessions per week (3 Zone 2 + 1 harder effort)
- Zone 2 sessions: 50–70 minutes each
- Quality session: 20 minutes with 2×8-minute Zone 3–4 intervals, Zone 2 between
The quality session introduces lactate threshold stimulus on top of the aerobic base you've built. Keep the hard session genuinely hard — most people train too hard on easy days and too easy on hard days.
After 8 weeks: what to expect
Eight weeks of consistent Zone 2 training typically produces:
- Measurably faster pace at the same heart rate (5–15% improvement is common)
- Lower resting heart rate (2–8 bpm lower is typical)
- Improved fat oxidation — you feel less depleted on long easy efforts
- Better recovery between workouts
VO2 max improvements from Zone 2 alone are modest but real over 8 weeks. The bigger gains come from the aerobic base that enables harder training — Zone 2 is the foundation, not the ceiling.
Tracking your plan with Underdog
Underdog tracks every minute of each Zone 2 session automatically via Apple Health. Your weekly points tally reflects your training volume across all zones — which makes the 8-week progression visible. A week where you hit 4 Zone 2 sessions will score significantly more points than a week of sporadic Zone 3 efforts, even if the calendar time is similar.
Use the Underdog league as a weekly accountability check. Your zone points don't lie about whether you actually did the work.