In a recent post we discussed why your run distance outdoors and run speed indoors may not always be what you expect.
In short: inaccurate course measurements, GPS errors, and weaving mean you will rarely run exactly 10k (for example) outdoors. On top of that, the mechanics of your treadmill, as well as footpod calibration errors, mean your indoor speed may not be what you think it is!
But here's the good news: the effort you put into your training sessions is much more important than the distance you may run.
Why Measure Effort?
If your training plan calls for a 7-mile threshold run, it doesn’t really matter if your run is just short of 7 miles or just over 7 miles. What matters is the ‘threshold’ effort.
Saying you ran 7 miles doesn’t tell us anything about how that session has impacted your fitness. But saying you ran for one hour in HR Zone 4 (threshold zone) while covering approximately 7 miles - now this is a lot more information!
Indeed, many training plans don’t mention distance at all. Instead, workouts are often described like this:
- 8 x 4 minutes at threshold effort with 2 minutes recovery
- One minute on, one minute off repeated 10x
How Effort Is Measured
There are four common ways to measure your running efforts:
- Pace; using Current or Average Pace you can define slow, medium and fast-paced sessions
- Heart Rate: running in zones 2-5 is a popular and simple way to measure your effort
- Power: while still a new metric, measuring effort by Running Power is becoming increasingly popular
- Perceived Effort/Exertion: running to feel can be of great benefit
Each of these methods has its benefits and drawbacks. Let's discuss!
Pace is probably the most widely-used method of measuring your effort in a race or training session.
In order to run to pace you need to define what your pace settings are. What is a slow, relaxed pace for you may be a medium or hard effort for someone else. Once you have completed a few runs, third-party apps like Strava will automatically create pace zones for you, much like heart rate zones.
Use these zones to target different fitness goals in your training. You may want to improve overall speed, or you may want to increase endurance capacity.
Running to pace is great for outdoor runs, but given that we cannot always be sure of accurate pace indoors, this may not be the best option for training on a treadmill. That said, if you turn on the graph within Zwift, your pace zones are shown along the bottom of your screen in real time.
Running to HR is a great way to monitor your effort, especially on Zwift. Set your Max HR by using a rough calculation based on your age or by running a hard effort, and apps like Zwift and Strava will automatically work out your heart rate zones for you.
Like running in pace zones, you can target specific training and fitness goals by running sessions in different heart rate zones:
- To improve speed you might run intervals once or twice a week in zones 4 or 5
- To improve cardiac function and strength, you might run for an hour in zones 3 and 4
- To improve endurance and base fitness you might run for 2 hours in zones 2 and 3
As long as your indoor running environment is not too hot, your HR should be comparable for similar efforts indoors and out. Your HR is always shown in Zwift, and just below that number is a real-time readout showing how many minutes you've spent in each HR zone.
While Running Power is still new to many, it has been around for a few years with companies including Garmin, Stryd, and Runscribe producing devices that can estimate your power output in Watts.
Once again, zones are used to divide levels of effort. Stryd, for example, uses zones based on Critical Power (CP), which is a figure derived from the power output of your first few runs using the Stryd footpod. A particularly hard effort will be around 120% of your CP, while an easy effort may be as low as 70% of your CP.
Using power to measure your running effort has some advantages over pace and heart rate. It is very difficult, and not advisable, to maintain the same pace or heart rate going uphill as it is running on the flat. However, you should be able to maintain a very similar power output regardless of the elevation profile.
Furthermore, unlike your heart rate, power is unaffected by illness or temperature and, unlike pace, it doesn’t care whether your treadmill is accurate or not!
Perceived exertion is simply measuring your effort by feel alone. This is easier than you might think! Often you can tell a run is ‘easy’ because you can hold a conversation with your running partner. Or you can tell a run is at maximum effort because your breathing is heavy and fast and your legs are burning.
It may take some experience before you can say with confidence that you are running in zone 4 or that you are outputting 300 watts. But being able to cross-reference what your devices are telling you with what your body is telling you can fill you with helpful confidence and motivation.
Admittedly, when you finish a race, the important metrics are generally how fast you ran and how far you ran. Speed and distance. But that race result comes from working hard and working smart in training!
Measuring your effort level using any of the above methods and balancing those efforts across your training is a key factor in achieving your best race times. So measure those efforts, train smart, and we wish you the best of luck on race day!