ZONE 2 TRAINING
Zone 2 training: what it is and how to find your pace
Zone 2 training is easy aerobic exercise at a pace where you can still speak in full sentences. In most five-zone systems it is the second-easiest zone. A 2010 review of how national and international level endurance athletes train found that about 80 percent of their sessions were at low intensity and about 20 percent were hard. To find your pace, use the talk test or heart rate zones built from your own data.
What zone 2 is
A heart rate zone is a band of heart rates that matches a level of effort. Watches and apps often use five zones. Zone 1 is the easiest and zone 5 is all-out. Zone 2 is the second from the easy end: steady and comfortable. Your breathing is deeper than at rest, and you can hold a conversation.
Systems number zones differently. Some research papers use three zones, split by two thresholds. Under that model everything below the first threshold is zone 1, which can span what a five-zone system splits into zones 1 and 2. This guide uses the five-zone meaning, as most watches and apps do.
The CDC gives a plain test for moderate effort: you can talk but not sing. For vigorous effort you cannot say more than a few words without pausing for a breath. In our coaching, zone 2 is the easy end of that range.
- CDC: measuring physical activity intensity (the talk test) checked 19 Oct 2026
How to find your zone 2 pace
The simplest method is the talk test. Run, ride or row at a steady pace and say a full sentence out loud. If you can say it without effort, you are in zone 2 or below. If you have to break the sentence to breathe, slow down.
Two studies tested this. In one, 16 physically active people ran 30 minutes at the pace of the last stage where they could still talk comfortably. Their heart rate, blood lactate and rating of effort stayed in a range that suits training. The authors say that pace suits long or recovery sessions for athletes and is an appropriate intensity for healthy adults.
In the other, healthy young adults did tests that moved their ventilatory threshold, the effort where breathing starts to climb faster than the work. The last pace where they could still talk comfortably moved with it. The study also found that the test errs one way: at efforts above the threshold, people sometimes still passed it.
That makes the talk test a way to find the top of the easy range, and it can read a little too fast. Our advice is to stay a little under the pace where talking first feels like work.
Heart rate gives you a second check. Complete sets your zones from your own heart data. If you have workouts in Apple Health, it analyses them during onboarding. The zones are built around your threshold heart rate, the rate at the edge between steady and hard effort, not a percentage of your maximum. Our guide to heart rate zones from your own data explains how.
- Woltmann et al., Journal of Strength and Conditioning Research, 2015: evidence that the talk test can be used to regulate exercise intensity checked 19 Oct 2026
- Foster et al., Journal of Cardiopulmonary Rehabilitation and Prevention, 2008: the talk test as a marker of exercise training intensity checked 19 Oct 2026
An easy run from Complete’s workout library
This is the Easy Run (Recovery), a session in Complete’s workout library. It takes about 35 minutes. Effort 3 out of 10 means easy enough to chat. The library note says it should feel relaxed and conversational, and that if you are tempted to push, you are going too hard.
If you are new, run 15 to 20 minutes, or swap it for an easy spin on any machine you have if your legs feel flat. If you are experienced, extend the main block to 40 minutes and keep the effort easy.
| Block | What you do |
|---|---|
| Warm-up | Run: 3 minutes at effort 2 out of 10. Start at a walk and drift into a jog. |
| Main | Run: 30 minutes at effort 3 out of 10. Relaxed and conversational. |
| Cool-down | World’s Greatest Stretch (a lunge with a twist that opens the hips and upper back): 1 set of 4 reps per side. |
A low-impact option on the rower
The library also has the Zone 2 Row, 40 continuous minutes on a rower for days your legs should not pound pavement. It takes about 50 minutes with the warm-up and cool-down. Row 5 minutes easy at effort 2 out of 10, then 40 minutes at effort 3 out of 10, then 3 minutes easy.
The library note says to keep a low stroke rate, 18 to 22 strokes per minute, with long unhurried strokes. It also says: if you are out of breath, you have left zone 2, so back off.
Why endurance athletes do so much of it
A 2010 review looked at studies of nationally and internationally competitive endurance athletes who trained 10 to 13 times a week. About 80 percent of their sessions were at low intensity. About 20 percent were dominated by hard work, such as intervals at about 90 percent of VO2max, the most oxygen your body can use in a minute. The review also says that studies adding more hard work for already well-trained athletes show no convincing long-term performance gains.
A 2006 study measured 11 nationally competitive junior cross-country skiers across 32 days. The authors used two thresholds to set three zones. By heart rate, 75 percent of the endurance sessions fell in the easiest zone, 8 percent in the middle zone and 17 percent in the hardest zone. The authors write that elite endurance athletes train little at the threshold intensity itself.
A 2014 study split 48 well-trained runners, cyclists, triathletes and cross-country skiers into four groups for 9 weeks. One group trained polarized: mostly easy, some hard and little in between. By the full text, about 68 percent of its time was low, 6 percent near the threshold and 26 percent high. That group’s peak oxygen uptake (VO2peak) rose 11.7 percent, the biggest rise of the four, and it led in most key endurance variables. The high-volume group and the threshold group did not improve further on the measured variables, apart from a slight gain in work economy in the threshold group.
Read these with care. The athletes train far more than most people. The first two papers describe what athletes do, so they cannot show that easy sessions cause the results. The 2014 study ran 9 weeks, which is short. In it, the group that mixed easy and hard work did best, and the high-volume group did not.
- Seiler, International Journal of Sports Physiology and Performance, 2010: what is best practice for training intensity and duration distribution in endurance athletes? checked 19 Oct 2026
- Seiler and Kjerland, Scandinavian Journal of Medicine & Science in Sports, 2006: quantifying training intensity distribution in elite endurance athletes checked 19 Oct 2026
- Stöggl and Sperlich, Frontiers in Physiology, 2014: polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training checked 19 Oct 2026
What zone 2 does and does not do
Online you will see zone 2 linked to mitochondria and fat burning. We do not make those claims here, because none of the sources on this page test them.
One study compared professional endurance athletes, moderately active adults and adults with metabolic syndrome during exercise. Across the tests, the athletes burned more fat and had lower blood lactate than the other two groups. It compared different people at one point in time. It does not show that easy training caused the difference.
Our coaching view is simpler. Easy sessions add aerobic volume at a low cost to recovery, which leaves you fresh for the hard and heavy days.
How much zone 2 to do
No study gives a single right amount of zone 2. Our advice is to keep most of your cardio easy. Two or three sessions of 30 to 45 minutes a week is a good start. Add time before you add speed.
Once easy sessions feel routine, add one hard session a week. Our Norwegian 4x4 guide has one. If you also lift, our concurrent training guide covers how easy and hard cardio fit around heavy leg days.
How Complete fits
Complete starts from your long-term goals: build muscle, lose fat, improve cardio, get stronger, general health or become an athlete. Easy cardio is one way to work on improving your cardio and your general health. Every workout that reaches Apple Health counts toward your score and your daily recommendation, in any sport.
Complete is free to download, and logging and sharing your workouts on it stay free.
Frequently asked questions
What is zone 2 training?
Zone 2 training is easy aerobic exercise at a pace where you can still speak in full sentences. In most five-zone systems it is the second-easiest zone. Runs, rides and rows can all be done in zone 2.
What heart rate is zone 2?
There is no single number. It depends on your body and on which zone system your watch uses. Use the talk test, or zones built from your own data. Complete sets your zones from your own heart data. If you have workouts in Apple Health, it analyses them during onboarding.
How do I know if I am in zone 2?
Say a full sentence out loud. If you can do it without effort, you are in zone 2 or below. If you have to break the sentence to breathe, slow down. Studies of the talk test found it can read a little too fast, so stay a little under the pace where talking first feels like work.
How long should a zone 2 session be?
Complete’s library has a 30-minute easy run, with a warm-up and cool-down, and a 40-minute row. For beginners the library suggests 15 to 20 minutes of running. Our advice is two or three sessions a week of 30 to 45 minutes.
Is zone 2 enough on its own?
In a 2014 study of 48 well-trained athletes over 9 weeks, the group that mixed mostly easy training with some hard work improved most. The high-volume group did not improve further on the measured variables. Our Norwegian 4x4 guide covers a hard session to pair with easy ones.
Does zone 2 training count in Complete?
Yes. Complete counts every workout that reaches Apple Health toward your score and your daily recommendation, in any sport. You can also log it in the app.