Jeroen Peerbolte
Zone 2 cardio is steady, easy endurance exercise at about 60–70% of your maximum heart rate: easy enough to talk in full sentences. Easy running, incline walking, cycling and rowing all count. Most adults aim for at least 150 minutes of moderate cardio a week, and zone 2 is a comfortable way to get there.
What is zone 2 cardio?
Heart-rate training splits effort into five zones. Zone 2 is the second-easiest: harder than a stroll, much easier than a workout. In a lab it sits below your first lactate threshold (Storoschuk et al., 2025). Outside a lab you can find it two ways:
- Heart rate: roughly 60–70% of your max heart rate, or 60–70% of your heart-rate reserve (Karvonen et al., 1957).
- The talk test: you can still speak in full sentences (Persinger et al., 2004). If you can only manage a few words, you are above it.
Zone 2 cardio and zone 2 running are the same idea. Running is just the activity where staying in zone 2 is hardest, because even a slow jog can push your heart rate up quickly.
Zone 2 cardio examples
| Activity | How to keep it in zone 2 |
|---|---|
| Easy running or jogging | Slow enough to talk; often well slower than you expect. Walk the hills if you need to. |
| Brisk or incline walking | A fast walk, hills or a treadmill incline brings many people into zone 2. |
| Cycling | Steady, conversational pedalling. Indoor trainers make it easy to hold one effort. |
| Rowing | Long, smooth strokes at a low stroke rate. |
| Swimming | Continuous easy laps; harder to monitor, so lean on the talk test. |
| Elliptical or hiking | Low impact, so you can add easy volume with less pounding. |
The activity matters less than the effort. Pick something you enjoy and can do for 30–60 minutes without your heart rate creeping up, and you have zone 2 cardio.
Zone 2 walking and treadmill workouts
If you are new to exercise, walking is often the easiest way into zone 2. Walk briskly, add hills, or use a treadmill incline: going uphill raises the effort steeply even at the same speed (Minetti et al., 2002). Fitter people may find walking stays below zone 2, and need a slow jog or a steeper incline instead.
On a treadmill, set the speed you can hold for the whole session and use the incline to fine-tune your heart rate. Raise it if you drop below zone 2, lower it when your heart rate drifts up late in the session.
How to find your zone 2 heart rate
Take 60% and 70% of your max heart rate. If you don't know your max, estimate it with 208 − 0.7 × age (Tanaka et al., 2001): for a 40-year-old that is 180 bpm, so zone 2 is about 108–125 bpm. The zone 2 calculator does the maths, including heart-rate reserve if you know your resting heart rate. More detail in heart rate zones for runners.
How much zone 2 cardio per week?
Common guidance for healthy adults is at least 150 minutes of moderate-intensity cardio a week (ACSM position stand, 2011), and zone 2 is a comfortable way to reach it. Endurance athletes do most of their sessions at low intensity too, often around 80% of their sessions, with a few hard ones on top (Seiler, 2010).
A practical start is three to five sessions of 30–60 minutes. Add time before you add speed, and keep one or two harder sessions a week if you want to get faster: zone 2 alone isn't the best stimulus for every adaptation (Storoschuk et al., 2025).
Benefits of zone 2 cardio
- A stronger aerobic engine. Endurance training increases the mitochondria in your muscles (Holloszy & Coyle, 1984).
- Better fat use. At low intensity a larger share of your energy comes from fat (Romijn et al., 1993), and training improves it.
- Volume without burnout. Easy sessions recover quickly, so you can train more often.
- Easy to start. It works with walking, cycling or swimming, not just running.
Common zone 2 mistakes
- Going too hard. Most people's “easy” is zone 3. If you can't talk, slow down.
- Ignoring drift. On long or warm sessions your heart rate rises at the same effort (Coyle & González-Alonso, 2001). Ease off to stay in zone.
- Using a wrong max. An age estimate can be off by 10 bpm or more. If zone 2 feels impossibly easy or hard, check your max.
- Staring at a screen. Checking your watch every minute is tedious. Heart-rate audio alerts tell you only when you leave the zone.
Zone 2 runs with ZoneTempo
ZoneTempo is an iPhone running coach that speaks over your music. Set zone 2 as your target and it tells you when you drift out of it, using the live heart rate from your WHOOP. See how ZoneTempo works →
Questions
What is zone 2 cardio?
Zone 2 cardio is steady, easy endurance exercise at roughly 60–70% of your maximum heart rate. You can still talk in full sentences, and you could keep going for a long time. Any activity counts as long as your heart rate stays in that range.
What are examples of zone 2 cardio?
Easy running or jogging, brisk or incline walking, cycling at a conversational effort, rowing, swimming, the elliptical and hiking. The activity matters less than the effort: what makes it zone 2 is keeping your heart rate at about 60–70% of max.
Is walking zone 2 cardio?
It can be. A brisk walk, a walk with hills or an incline walk on a treadmill often reaches zone 2, especially for less fit people. An easy stroll may stay below it. Check with a heart-rate monitor or the talk test.
How long should a zone 2 cardio session be?
Common guidance for adults is at least 150 minutes of moderate cardio a week. In practice that is often three to five sessions of 30–60 minutes. Longer sessions are fine as long as the effort stays easy.
Is zone 2 cardio good for fat loss?
At low intensity your body gets a larger share of its energy from fat, and endurance training improves fat use. But fat loss depends on your overall energy balance, so zone 2 is a sustainable way to add training volume rather than a shortcut.
Sources
- Storoschuk KL, Moran-MacDonald A, Gibala MJ, Gurd BJ. Much ado about zone 2: a narrative review assessing the efficacy of zone 2 training for improving mitochondrial capacity and cardiorespiratory fitness in the general population. Sports Med. 2025. doi.org/10.1007/s40279-025-02261-y
- Persinger R, Foster C, Gibson M, Fater DC, Porcari JP. Consistency of the talk test for exercise prescription. Med Sci Sports Exerc. 2004;36(9):1632–1636. pubmed.ncbi.nlm.nih.gov/15354048/
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37(1):153–156. doi.org/10.1016/S0735-1097(00)01054-8
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate; a longitudinal study. Ann Med Exp Biol Fenn. 1957;35(3):307–315. pubmed.ncbi.nlm.nih.gov/13470504/
- Garber CE, Blissmer B, Deschenes MR, et al. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults. Med Sci Sports Exerc. 2011;43(7):1334–1359. doi.org/10.1249/MSS.0b013e318213fefb
- Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform. 2010;5(3):276–291. doi.org/10.1123/ijspp.5.3.276
- Holloszy JO, Coyle EF. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. J Appl Physiol. 1984;56(4):831–838. doi.org/10.1152/jappl.1984.56.4.831
- Romijn JA, Coyle EF, Sidossis LS, et al. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Am J Physiol. 1993;265(3):E380–E391. doi.org/10.1152/ajpendo.1993.265.3.E380
- Minetti AE, Moia C, Roi GS, Susta D, Ferretti G. Energy cost of walking and running at extreme uphill and downhill slopes. J Appl Physiol. 2002;93(3):1039–1046. doi.org/10.1152/japplphysiol.01177.2001
- Coyle EF, González-Alonso J. Cardiovascular drift during prolonged exercise: new perspectives. Exerc Sport Sci Rev. 2001;29(2):88–92. doi.org/10.1097/00003677-200104000-00009
ZoneTempo is an iPhone running coach that speaks pace and heart-rate cues over your music. Free to use, with 3 Pro runs on us.
This guide is general information, not medical advice. Check with a doctor before starting a new exercise routine if you have a heart condition or other health concerns.