Run slow to run fast…
Written by Daniel Barratt - Level 2 Qualified Running Coach
“Your easy running should be about it feeling easy”.
Why is zone 2 running important?
This is one of the common myths in running. You don’t need to try and run as hard and fast as you can every time you go out for a run. In fact, it’s beneficial for you and your training to try and slow yourself down. By slowing yourself down for a proportion of your running, you can end up running faster.
The term Zone 2 refers to our heart rate zones and is measured in different ways, but is defined as an aerobic zone and is generally best measured by our heart rate zone. There are different ways of measuring it and factors influence it including age and conditions, but a good benchmark for Zone 2 is below 150 bpm.
Why should you run slower?
There are a number of fitness and training benefits to running slower. First of all, by running slower, you can run for longer. Running slower is inevitably easier, which means we can run for much longer before the body gets tired. This is both in terms of a specific session, but also in relation to our long term running longevity. Running for longer at a lower intensity has aerobic benefits for our fitness by making our running economy (i.e. the amount of energy required to run at a specific pace or for a specific time) more efficient.
The next - recovery. Our ‘slower’ running can take different forms in our running training. It can be an entire run, such as 60 mins in Zone 2, or segments within a training session such as a tempo session where we vary our pace. It can also be in our warm ups and cool downs as part of a training session.
For example, a tempo session might look like this.:
2km warm up
4 x 1km @ half marathon pace, 1km easy,
2km cool down
6km or 60% of this run will be done at an ‘easy’ or slow pace. In terms of recovery, the recovery between the reps in a working session allows time for us to recharge ready to work again. When it comes to Zone 2 sessions, generally these are placed in between our harder sessions and used as recovery sessions and to improve our running economy. In these sessions the slower and easier we run the more our body can recover between our harder sessions so that we’re fresh again to push in our hard sessions. The more we can push in our hard sessions, the more we push our pace boundaries, increase our fitness and in turn get faster.
How much of your running should be slow?
The amount you should run slower depends on what type of runner you are and any other training beyond running. Generally, a good range to aim to run slower is around 70-80% of your weekly volume (for more on this see the 80/20 Training Method by Matt Fitzgerald). By volume, we don’t mean sessions, but in terms of your weekly mileage/KMs. What this means is you should aim to together all of your zone 2 sessions, warm ups, cool downs and any floats in your harder sessions. For a 50km per week runner, this will look like 10-15km per week of harder training, i.e. threshold, intervals, hill work and 35-40km cumulative easy running.
How slow should you run?
There are a number of ways we can determine how to run ‘easy’. The first of these is to rule out pace. Your easy ‘pace’ will vary based on your level of ability, training schedule, lifestyle factors, time of day, session dynamics and a whole host of variable factors. I know, this might seem like it will ruin your Strava cred, but a faster 5km PB will look way cooler. That’s where we can turn to heart rate as a more reliable factor for those that like data. As mentioned, being able to run below 150bpm for Zone 2 sessions is a good guide, and the lower we can get it the better, as this means your body isn’t working as hard (thinking back to recovery).
However, heart rate can also be variable, based on sleep, elevation, time of day, caffeine intake, anxiety, watch quality and more, so I always like to use heart rate as the output just for Zone 2 based sessions. If we are using ‘easy’ running for pace variation within a workout then your heart rate will take time to slow down so isn’t a good indicator.
The easiest way I like athletes to measure whether they are running easily enough is by the talking test. If you can’t have a conversation in full sentences whilst you’re running, then you’re going too fast. That’s why full zone 2 running is great to do with a friend for a catch up, or a good opportunity to call a friend. That way you’re not constrained by the data, and your easy running should be about it feeling easy.
So to summarise, running slower can help you to run faster.
Key takeaways:
Running slower allows you to run for longer, improving running economy
Running slower allows you to recover within a session, to help hit pace goals
Running slower enables better recovery between sessions so we can be fresh to push our limits in workouts
Heart rate is a useful metric for Zone 2 sessions.
How slow we run doesn’t matter, it’s about it feeling easy which the talking test can validate
If you are new to running and all running feels the same then that’s okay. With time, training and variety in your sessions, you won’t be far away!