Runners and swimmers have long used pace to prescribe and monitor training intensity. But before the advent of GPS watches, doing so required a track, pool, or route with distances marked at regular intervals, along with a basic stopwatch on your wrist. GPS watches opened up the use of pace on trails and roads without marked distances; and a GPS watch can tell you your pace or speed without needing to make calculations based on your recorded time over a given distance.
As a tool for targeting training intensity, pace works best on relatively invariable terrain, such as on the track while running or in the pool while swimming. If you’re on terrain with hills, in open water with currents, or in variable conditions that may include wind or uneven terrain; then pace becomes less reliable as a tool to measure your workout intensity.
Running a 6-minute mile uphill obviously puts you in a higher intensity zone than running a 6-minute mile on the track. But if you can determine your running pace for a given intensity going up that hill; then you can certainly use pace when training on that hill or hills of an equivalent grade. The point is that pace is not only specific to the activity you’re doing (running vs. swimming vs. cross country skiing vs. cycling), but it’s also specific to the terrain (and conditions) where you’re doing the activity.
Pace will most commonly be used for running or swimming, but the same process applies to any endurance activity. Determining your pace range for each of the Alp Fitness intensity zones first requires doing a field test to find your pace at lactate threshold since the zones are based on percentages of that lactate threshold pace.
Functional Threshold Pace, or FTPa
Your pace at lactate threshold is termed functional threshold pace, or FTPa where the “Pa” at the end indicates “pace” since the abbreviation FTP is typically used to indicate “power.”
The word “functional” refers to the fact that we’re using a practical performance-based test rather than a lab test. Rather than directly testing for blood lactate concentration, as would be done in a lab to precisely pinpoint your lactate threshold (LT), we’re indirectly approximating your LT and are more interested in your effective, or functional pace at that physiological point of interest than the precise biomarker itself.
What about NGP on TrainingPeaks and GAP on Strava?
If you use TrainingPeaks or Strava, you may see metrics in your workouts for Normalized Graded Pace (NGP) or Grade Adjusted Pace (GAP). These metrics use algorithms to grade or adjust your running pace on hilly terrain in terms of an equivalent run on flat, level terrain.
For example, if you run 18 miles at an 11-minute per mile pace on a route with about 300 feet per mile of elevation change, your GAP would be about a 10-minute per mile pace — the pace you would have held for that run over 18 miles if the route was on flat terrain.
Metrics like NGP and GAP are useful for comparing effort levels over different terrains after the fact. But these figures aren’t available on your watch to monitor your intensity in real time. So you’ll still need to go back to that all-important ability to cue into your intensity level by feel — and perhaps use another tool, such as heart rate.