You will have noticed that Coach Jim often refers to training zones in his workouts. What exactly do those mean and how can you learn to assess your own intensity? One of the easiest measures of intensity is based on your personal maximum heart rate from which tables of varying zones can be created. Some people prefer to work with zones based on VO2 MAX, while others prefer lactate threshold heart rate zones. Some prefer zones based on run paces, or even more simply, perceived exertion.

Establishing a Baseline

There are many ways to work out your maximum heart rate (MHR). One is to use the formula 208 minus (0.7 x current age). There are also a number of workouts that can give you an idea of your MHR.

Perceived exertion is often the best approach to apply to your training. It accounts for where you are at on any given day and relies on an intuitive sense of pace and effort.

Using your known race paces can also help you identify your run zones if you don’t wear a heart rate monitor. Results of one race can be extrapolated using pace tables; there is no need to race all distances.

80/20 Rule

In one weekly email, Coach Jenn underscored that we should all be trying to balance our training volume according to the 80/20 rule. This balanced training is key to building run strength and endurance. Basically, this rule stipulates that runners should aim to spend about 80% of their weekly training time at moderate intensity (a comfortable pace where conversation is definitely doable), and about 20% at moderate to high intensity.

As competitive amateurs, we need to keep it simple. Become accustomed to judging the intensity of a run within yourself (even if you do use metrics) and follow the 80/20 approach in your overall run volume. Using metrics and recording data is useful particularly for plotting trends in your training that can be insightful when looking back at what worked or didn’t, but don’t let data and technology drive your running, or worse, take the fun out of a sport we love!

Summary Table

Based on MHRPerceived ExertionRace PacesBalancing Run Volume
Zone 1MHR – 50Very lightEasy80-85%
Zone 2MHR -40LightEasy
Zone 3MHR – 30ModerateMarathon10-15%
Zone 4MHR – 20Hard(a) Half Marathon
(b) 10km
Zone 5MHR – 10Very Hard(a) 5km
(b) 600m to 1 mile
(c) less than 600m

We can also divide training intensity into pace specific zones. The figures and paces in the chart below are not fixed, rigid or absolute, but they can help you determine your ballpark pace for general interval sessions. 

RunnerAerobic Threshold /
10km best time
Zone 5 Pace
Zone 4 Pace
Zone 3 Pace
(max 90-95%)
Zone 2 Pace
(max 85-90%)
Zone 1 Pace
(about 80%)
A3:49 / 36:00<3:483:494:024:154:30
B4:00 / 38:00<3:594:004:134:284:45
C4:11 / 40:00<4:104:114:244:384:55
D4:33 / 44:00<4:304:334:455:025:20
E4:46 / 46:15<4:454:465:015:185:37

Let’s take Runner B. She has an anaerobic threshold of 4:00 min/km, which is based on her recent best 10 km race of 38 minutes. 

Zone 5, which we only use a few times in spring and summer training, is very fast running over relatively short distances. In this zone, the runner is not able to deliver enough energy to the muscles, meaning the body produces more lactic acid than it can get rid of. Runner B will be aiming to run her intervals at 3:59/km or faster.

Zone 4 is where we train when we’re running anaerobic threshold runs, such as 3x 3km with 4 minutes rest. Runner B would aim for her intervals to be 4:00 min/km. 

Two things happen when we train in Zone 4: we get faster, with our body producing and getting rid of lactic acid effectively; and we increase the time and/or distance that we are able to maintain our anaerobic threshold. 

In order to be able to benefit from Zone 4 training, the runner needs to build a good aerobic base through a significant amount of running in Zones 1 and 2. An important aspect of training in Zone 4 is pacing: we should aim to end the last interval at the same pace as the first and second. Runners with little experience tend to run the first interval too fast, which will decrease the effectiveness of the training. 

Coach Jims Reminders for Zone 4 workouts

We are looking for the result of the training, not the training results!

In Zone 4, we are still able to talk in short sentences (3-5 words per breath), but will not be able to keep up a conversation of longer sentences.

In Zone 4, the arms and legs should still feel coordinated and not heavy and shaky. Heavy arms and uncoordinated legs are signs of a Zone 5 type intensity

Zone 4, for a professional athlete, is a pace that can be maintained for 15-21km. For us amateurs, we are looking at a distance of about 10km

Zone 3 moves down 5-10 % in pace intensity (remember: this would be the same for the heart rate if you prefer to use a chest band to monitor your training intensity). Getting back to Runner B, this would be around 4:13 min/km. 

A typical Zone 3 workout would be 8-12 minutes easy jog in Zone 1, followed by a single repetition of 15-45 minutes of moderate running.

As Harriers, we use Zone 3 quite often as an extended warmup before Zone 4 running (intervals, hills repeats). It is also an effective method to end a workout. Let’s say we do hill repeats and accidentally build up more lactic acid than we intended. A 5-15 minute cooldown in Zone 3 is quite effective as a response. 

There is a bit more slack when working in Zone 3. If we don’t want to worry about our pace or heart rate, just use a running mate! We can check our breath or intensity with some small talk: in general, we should be able to string a sentence together of more than five words. We are able to think about things other than our actual workout, and we actively enjoy our surroundings. It’s also a great time to work on the more technical aspects of our running: staying tall, and landing with quick, gentle steps.

Zone 2 and Zone 1 are our easy long runs. Together they form 70-80 % of our total weekly running time or distance. Runner B is aiming for 4:28-4:45/km. We feel like we can go forever at this pace!


Various things influence your pace for a specific day, specific interval session, in a specific season. Think of:


  • temperature, humidity, winds

Running surface

  • incline, ice, slushy, off road, trails, track

The runner

  • motivation, rested, stress, eating, sleep

Of course there are many more factors that influence your running almost daily!

Categories: Journal