It sounds backwards: to run faster, slow down. Yet it's the most consistent finding about how good endurance athletes train, and the most common mistake among everyday runners. This guide explains why easy running works, how to know your runs are really easy, and how a watch can help without taking over.
In short. Make about 80 % of your running easy: slow enough to talk in full sentences. Keep the other 20 % for real quality work. Most runners run their easy days too fast and their hard days too slow; spreading them further apart is often the quickest way to improve.
Why easy running works
Easy running builds the parts of your fitness that take months: more small blood vessels in your muscles, more of the machinery that turns fuel into energy, stronger tendons and bones. It does this while leaving you fresh enough to run again tomorrow, and to run your hard sessions properly.
Studies of well-trained endurance athletes in running, cycling, rowing and skiing find the same pattern: roughly 80 % of training at a low intensity and about 20 % at moderate to high intensity. When everyday runners are asked to train this way, they usually improve at least as much as on a plan of medium-hard runs, while feeling less tired.
What many runners do
What works better
EasyMedium, "comfortably hard"Hard
How easy is easy
Easier than most people think. Three ways to check, from simplest to most precise:
- The talk test. You can speak in full sentences without gasping. If you can only manage a few words at a time, you're no longer running easy.
- Heart rate. Easy running usually sits below about 75 to 80 % of your maximum heart rate, or below about 85 to 89 % of your threshold heart rate (the effort you could hold for about an hour). On a five-zone scale, that's zones 1 and 2.
- Pace. Typically 60 to 90 seconds per kilometre slower than your 10 km race pace, sometimes more for newer runners.
| Effort | Talk test | Heart-rate zone | Used for |
|---|---|---|---|
| Easy | Full sentences | Zones 1 to 2 | Most runs, long runs, warm-ups |
| Medium | Short phrases | Zone 3 | Tempo runs, marathon pace |
| Hard | A word or two | Zones 4 to 5 | Intervals, races |
On hilly routes, in the heat or when you're tired, easy pace gets slower. That's fine: keep the effort easy, not the pace. Walking up steep hills on an easy day is completely normal.
The common mistakes
- Running every run at the same medium pace. It feels productive, but it leaves you too tired to run fast on the days that count.
- Chasing pace on easy days. Comparing your easy runs with last week's, or with a friend's, pushes them up into the middle zone.
- Making the hard days too easy. If most of your running is easy, your one or two quality sessions should feel properly hard.
- Trusting a single number. Heart rate from a wrist sensor can jump around, especially in the first minutes and in the cold. If the number and your breathing disagree, trust your breathing.
How to actually slow down
Knowing you should run easy is one thing; doing it is another, especially when slow feels awkward. A few tricks help:
- Run by time, not distance. "40 minutes easy" removes the temptation to hurry to the end.
- Hide the pace. Set your watch to show time and heart rate on easy days, with an alert at the top of your easy zone.
- Run with someone slower, or with a friend you can chat to the whole way.
- Walk the steep hills. It keeps the effort easy and costs very little time.
- Be patient. The first weeks can feel frustratingly slow. Over a few months, most runners find their easy pace gets faster at the same heart rate: that's the fitness easy running builds.
What goes in the other 20 %
The hard part of the week should be short and clear: one or two sessions of intervals, a tempo run, hill repeats or a race. Run them properly, warmed up and at a strong effort, then go back to easy running. If a hard session feels impossible, it's often a sign that the easy days weren't easy enough.
New runners don't need much hard running at all. For the first months, almost everything can be easy, with a few short strides at the end of a run once a week.
An 80/20 week
| Day | Run | Effort |
|---|---|---|
| Tuesday | 45 min with 5 × 3 min hard, 2 min easy between | Hard (about 15 min of it) |
| Thursday | 40 min, finishing with 5 strides | Easy |
| Saturday | 35 min | Easy |
| Sunday | 70 min | Easy |
That's about three hours of running, of which roughly 15 to 20 minutes are hard: the rest, warm-ups and recoveries included, is easy. It feels like very little hard work, and that's the point.
How a watch helps
A watch is most useful after the run rather than during it. Look at your time in each heart-rate zone over a week or two: if most of your easy runs land in zone 3, slow them down. Set your zones from your own threshold or a recent race, not only from your age. And during the run, an alert when you go above your easy zone is often all you need.
If your heart rate is unusually high on an easy run for several days in a row, or your morning heart-rate variability stays low, you may be tired or getting ill. Take a few easy or rest days. Chest pain, dizziness or an irregular heartbeat are a reason to stop and see a doctor.
Run to your own zones in MyTrainingDesk
MyTrainingDesk works out your heart-rate and pace zones from your own thresholds, shows how much of each week you spent easy, medium and hard, and builds your sessions to those zones. Ask the coach whether your easy runs are easy enough, and it answers from your own data.
Read next
Sources
- Seiler KS, Kjerland GØ. Quantifying training intensity distribution in elite endurance athletes: is there evidence for an "optimal" distribution? Scandinavian Journal of Medicine & Science in Sports, 2006; 16(1): 49–56.
- Esteve-Lanao J, Foster C, Seiler S, Lucia A. Impact of training intensity distribution on performance in endurance athletes. Journal of Strength and Conditioning Research, 2007; 21(3): 943–949.
- Stöggl T, Sperlich B. Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training. Frontiers in Physiology, 2014; 5: 33.