Your running watch is a data firehose. Pace, distance, heart rate, cadence, ground contact time, vertical oscillation, power, stride length, training effect, VO2max estimate, body battery, stress score, sleep score, recovery advisor, and a dozen more. Every metric has a screen, a graph, and a trend line.

Most of it doesn’t change what you should do on your next run.

The 5 That Matter

1. Pace / Distance

The basics. How far you ran and how fast. This is the foundation of all training tracking — your weekly mileage, your long run distance, your interval splits. Every training decision references pace and distance.

2. Duration

How long you ran. For RPE-based training load calculation (duration × RPE), this is one of the two essential inputs. Duration is often more useful than distance for easy runs — running by time rather than mileage removes pace pressure.

3. Heart Rate (Average, Not Real-Time)

Average heart rate over a run — particularly over easy runs — tracks aerobic fitness trends over time. A declining average heart rate at the same pace means your aerobic system is becoming more efficient. Pacewright uses this for its efficiency factor calculation. Real-time heart rate is less useful (see the wrist monitor accuracy article).

4. Elevation / Climb

How much you climbed matters for understanding the actual effort of a run. A 5-mile run with 500 feet of climb is a very different workout than a flat 5-mile run. Pacewright uses elevation data for grade-adjusted pace calculations.

5. GPS Track

The route you ran. Useful for analyzing terrain, identifying where pace changed, and verifying distance accuracy. GPS tracks also let Pacewright correlate your run with weather data for environmental adjustments.

The 10 That Don’t

Cadence

Your steps per minute. The “180 spm is optimal” advice is a myth — it came from observing Olympic runners at race pace, not prescribing what all runners should do at all paces. Cadence varies naturally with pace, height, and leg length. There’s nothing actionable to do with this number.

Ground Contact Time

How long your foot is on the ground per stride. Shorter is theoretically more efficient, but consciously reducing ground contact time leads to choppy, forced running mechanics. This metric improves naturally as you get faster. Watching it doesn’t help.

Vertical Oscillation

How much you bounce up and down. Less bounce is theoretically more efficient, but like cadence and ground contact time, it self-optimizes with training. Trying to reduce bounce consciously creates tension that wastes more energy than the bounce itself.

Running Power

Watts. A relatively new metric that attempts to quantify running effort the way cycling power does. The problem: unlike cycling power (which is measured directly by a force sensor), running power is estimated from accelerometer data using proprietary algorithms. Different watches produce different watt numbers for the same run.

Training Effect

Garmin’s assessment of how productive your workout was (aerobic, anaerobic, or “overreaching”). This is a proprietary score based on heart rate patterns. It can’t account for your training history, your goals, or your overall weekly plan. A hard interval session might show “overreaching” on the watch but be perfectly appropriate within your training cycle.

Body Battery / Stress Score

Composite readiness scores that combine HRV, heart rate, sleep, and activity data. These are too noisy at the individual level to drive training decisions. Your RPE during the first 10 minutes of running is a better readiness indicator.

VO2max Estimate

Your watch’s estimate of your maximal oxygen consumption. Useful as a long-term trend, but the absolute number is unreliable (can be off by 5-10% from a lab test), and chasing the number leads to bad training habits (running easy days too fast to inflate the estimate).

Performance Condition

Garmin’s real-time assessment of whether you’re performing above or below your recent baseline. Interesting but not actionable — you’re already running. Knowing mid-run that your “performance condition” is -3 doesn’t change what you should do.

Lactate Threshold Estimate

Watch-estimated lactate threshold from heart rate data. The estimate requires specific guided test protocols and still isn’t as accurate as a blood lactate test. RPE 6-7 is a simpler and equally effective way to target threshold effort.

Sleep Stages

Your watch’s breakdown of light, deep, and REM sleep. The accuracy of wrist-based sleep staging is poor compared to clinical polysomnography. Total sleep time is a better metric than the stage breakdown.

The Rule

If a metric doesn’t change what you should do on your next run, you don’t need to look at it. More data doesn’t make you a better runner. Better training makes you a better runner. The data is only useful to the extent that it informs training decisions — and five metrics do that job.