Your 12-week zone 2 and VO2 max training plan

What is zone 2 training?

Zone 2 is steady aerobic exercise just below the point where your breathing becomes noticeably harder. You can speak in full sentences, nose-breathing is usually possible, and you could keep going for an hour or more.

It matters because easy aerobic work builds the engine every other kind of fitness runs on: more capillaries, more and better-functioning mitochondria and a heart that pumps more blood per beat. It is also easy enough to repeat most days without wrecking your recovery, which is why endurance athletes spend most of their training time here. The journal uses a simple three-zone chart rather than a five-zone system, because you only need to know your easy range, your hard range and the recovery range below both.

How do I calculate my zone 2 heart rate?

Estimate your maximum heart rate with the Tanaka equation (208 − 0.7 × age), then take 60–70% of your heart-rate reserve, which is maximum minus resting heart rate, and add your resting heart rate back. This is the Karvonen method. Without a resting heart rate, use 60–70% of maximum instead; the range comes out lower and wider.

Tanaka, Monahan and Seals published the equation in 2001 after finding the old 220 − age formula underestimated maximum heart rate in older adults. Any age-based formula is still an estimate: two people of the same age can differ by 10 bpm or more. That is why the journal pairs every number with the talk test. Measure resting heart rate lying down on waking for three mornings and take the average. The free zone 2 heart rate calculator does the maths for you.

How many minutes of zone 2 per week?

Build towards 150–240 minutes a week, spread over 3–6 sessions. The WHO's 2020 guidelines recommend 150–300 minutes of moderate activity a week for adults, plus muscle-strengthening on two or more days, and zone 2 sits comfortably inside that moderate band.

Start from what you already do, not from the target. The plan begins at your current weekly minutes (at least 60), climbs over eight weeks to 180 minutes for long-term health, 210 for fat loss or 240 for performance, and cuts volume by about a quarter in weeks 4, 8 and 12 so you absorb the work. From week 3 one session becomes a longer one, capped at 90 minutes. Here is the ramp for a 44-year-old who currently does 90 minutes a week on four days.

Busy week? Keep the long session and one shorter one, and let the rest go; that keeps most of the benefit. Two missed weeks in a row is the point to repeat the previous week rather than jumping ahead.

How to improve VO2 max: the Norwegian 4×4

The most reliable way to improve VO2 max is a weekly session of hard intervals on top of a solid zone 2 base. The Norwegian 4×4 is four 4-minute efforts at 85–95% of maximum heart rate, each followed by 3 minutes of easy movement. In a 2007 study by Helgerud and colleagues, this format improved VO2 max more than the same amount of work done at a moderate steady pace.

VO2 max matters beyond sport. A 2018 JAMA Network Open study by Mandsager and colleagues followed adults who completed treadmill tests and found higher cardiorespiratory fitness was strongly associated with lower long-term mortality. That is an association, not proof that any single workout adds years, but it is a good reason to keep both zone 2 and some hard work in your week.

One 4×4 a week is enough for most people. Keep it at least two days away from your longest session and do it on a bike, rower or hill if hard running hurts your joints.

• Warm up for 10 minutes in zone 1 to 2
• 4 × 4 minutes in your zone 4 range with 3 minutes easy between; the first should feel controlled, the last hard but finishable
• Judge the first minute of each interval by breathing; heart rate lags behind effort
• Cool down for 5 minutes, then log your average heart rate for each interval

Is zone 2 cardio good for fat loss?

Zone 2 helps fat loss mainly because it lets you add a lot of weekly activity without the fatigue that makes you move less the rest of the day. It is not a magic fat-burning zone. Fat loss comes from a sustained energy deficit, and the share of fat you burn during a session matters far less than your total energy balance across weeks.

Where zone 2 earns its place is consistency: 210 minutes of easy cardio a week is realistic for many people, while 210 minutes of hard intervals is not. Pair it with the two short strength sessions in the plan to protect muscle while you lose fat, and with enough protein; the high-protein meal plan covers the food side.

Zone 2 walking, running, cycling or rowing: which is best?

The best mode is the one that keeps your heart rate steadily in range and that you will repeat several times a week. Cycling makes the steadiest heart rate easiest and is kindest on joints; running reaches zone 2 fastest but is easiest to overdo; brisk or incline walking works well for beginners and older adults.

Heart rate drifts upward during long sessions, in heat, with caffeine and after poor sleep. When that happens, slow down to stay in range rather than chasing a pace. A chest strap reads far more reliably than a wrist sensor, especially during the 4×4.

• Walking: add incline or a weighted vest once flat walking no longer reaches zone 2
• Running: zone 2 is often much slower than you expect; walk the hills to stay in range
• Bike: the easiest way to hold a steady heart rate for 60–90 minutes
• Rower: keep the stroke rate around 18–22 per minute and drive with the legs

Common zone 2 mistakes

Most zone 2 plans fail because the easy days drift too hard or the weekly minutes jump too fast. Both are easy to fix once you log them.

• Going too hard. If you cannot finish a sentence, you are above zone 2. Slower is the point.
• Doubling volume overnight. Add roughly 10–20 minutes a week and take the easier weeks.
• Trusting a formula over your body. If the bpm range feels much too easy or too hard, use the talk test and retest resting heart rate.
• Using heart rate zones on beta-blockers. These drugs blunt heart rate, so the numbers mislead; use perceived effort and your doctor's advice.
• Skipping strength. Two 20-minute sessions a week protect muscle and bone alongside your cardio.

Updated October 18, 2026 · Written by the Kilopace editorial team