Check out these simple explanations of when to use which and how they should intersect.
Unless you’ve taken a running hiatus, you’ve noticed that it’s summertime, it’s hot, and running is lot tougher right now at a given pace! If you’ve set your running heart rate and pace zones in the past then read on. If not, visit Joe Friel’s Lactic Threshold Heart Rate primer and make sure you’re using accurate zones as a starting point.
Pace is considered the gold standard of run effort measurement because it is truly objective. Heart rate is a subjective measure of what’s happening. Using these metrics together can give you the best bang for your buck. Shouldn’t pace and heart rate zones track together? Most of the time and certainly during races, but not always.
Below, let’s review a few times where you would want to differentiate between pace and heart rate as drivers.
The Easy Run
On a hot summer’s day your pace may very well be zone 2 while your heart rate is zone 3 and beyond. This is a situation where I advise my athletes to look at heart rate as the primary driver. If you are constantly running at a high heart rate to hit an arbitrary pace on easy days, then you’ll be too worn out to hit your quality workouts.
Summer Easy Run Tip: The idea of an easy day is that it’s truly easy, so don’t get caught up in worrying about what your easy pace was during the cooler months!
Besides the treadmill, the track is the closest we have to all factors being equal—it’s flat and it’s a standard length. This is why it’s the preferred place to run set distance intervals with pace as a primary driver.
Summer Track Tip: Start early. Start earlier than the time that just popped into your head. If the goal is to hit the pace then you want to make it as easy for yourself as possible which means running in the coolest part of the day, early AM or late PM.
The Long Run
If you’re half or full marathon training, your key long runs will likely include some miles at race pace. For these runs, consider using a mix of heart rate and pace to execute your long run. For instance, if you are targeting a 13-mile long run with the last three miles at race pace, run the first ten by heart rate (i.e. at an easy pace). That way when it’s time to ramp it up, you won’t already be exhausted from arbitrarily trying to hit a pace in the beginning.
Summer Long Run Tip: Frame your entire run around executing your race pace miles. For example, run the warmup section very easy and hydrate and fuel like a champ. Oh, did we mention the value of starting early?