Your Watch and Your Body Are Both Right
Why the pacing debate is the wrong argument, and what the data and feel are each actually telling you
A few weeks ago, I posted a social post about training by heart rate, and a comment on it made me pretty confused. One of those replies that comes in long, certain, with no hedging: Pacing by feel is the only accurate way to do it. HR is meaningless.
I know plenty of runners who just go by feel. But I’ve never seen a comment so confident that it's the only meaningful way to train. It wasn’t about preference or misunderstanding how to read data from a smart device. It was a different claim entirely.
Most runners who train by feel aren’t necessarily doing anything wrong - they’re just not maximizing their training effort. They finish workouts, they log the miles, they make progress. But they’re guessing at recovery, intensity, and whether their effort matched what would produce change.
And without the data half of training, there’s no way to know.
The Feel-Only Position Mistakes a Skill for a System
RPE - rate of perceived exertion - is a legitimate, research-backed input. RPE integrates environmental conditions into the effort signal in a way that raw pace can’t. When it’s hot and humid, a 9-minute mile costs more than it does on a cool morning. Your body already knows that. A pace number doesn’t.
The problem isn’t that feeling something is easy or hard is inaccurate. It’s that feel is personal, variable, and context-dependent in ways the person experiencing it doesn't always see.
Two athletes running at the same objective intensity - for instance, 95% of their lactate threshold - can report completely different RPE numbers. Both admit it’s a challenge, but one rates it a 6 while the other rates it a 9.
Both are being honest in their score, but if they’ve never calibrated their personal RPE against external data, they don’t know where their 6 actually lands relative to their physiology. They have a feeling without a reference point.
Feel also drifts in ways that matter. In my coaching experience, adrenaline on race morning suppresses perceived exertion - the first miles feel easier than they are. Conversely, accumulated fatigue makes easy effort register harder than it should. These aren’t edge cases; they’re examples of specific moments when feel is most likely to mislead you and when a second input matters for the full picture.
But before we go all in on data, it’s important to call out RPE's value: It's easy to let numbers and quantitative metrics rule your training practice. A pace target that doesn’t account for how the body is responding is just a number you’re chasing. The data-only runner is running a different version of the same problem.
You Can’t Fix What You Can’t See
Going feel-only doesn’t fail you in one race. It fails you across a training block, one undetected bad decision at a time.
Recovery is one place this shows up clearly. Without heart rate data, you’re left guessing at your readiness - and feel is a poor proxy for what’s actually happening. A slow return to baseline HR after effort. An abnormally high or low resting HR the next morning. Heart rate that fails to reach its normal peak at a corresponding effort level. None of those show up in a numeric score for how you feel.
You can be under-recovered and feel fine, or recovered and feel flat, and have no way to tell the difference.
That’s just one way training blocks go sideways. Easy days that aren’t easy enough. Hard days hitting a system that hasn’t come back. A block that looks right on paper and doesn’t produce what it should - and no way to know why.
The Inputs Measure Different Things
Data tells you what is happening. Feel tells you how your body is interpreting it. The skill is learning to read both and know what it means when they tell different stories.
In a training run, the clearest example is cardiac drift. As a run extends and body temperature rises, heart rate climbs even when pace stays the same. Your body works harder to cool itself, burns more fuel, and pushes toward thresholds, even if the effort doesn’t feel like it changed. Cardiac drift can elevate HR by 10 to 15 beats per minute.
If you’re running by feel alone in the second half of a long effort, you may not notice, but the heart rate data catches it. When HR climbs without a corresponding increase in perceived effort, that’s your signal to pull back pace and manage energy output. The physiological cost is higher than your RPE is reporting.
RPE also helps you interpret how environmental conditions affect your HR. Heat, humidity, and wind elevate heart rate independently of running workload. If your HR is high and your RPE confirms the effort feels harder than usual, that’s consistent - conditions are raising the cost of the run and your body is registering it. Adjust accordingly.
What Calibrating Both Inputs Actually Looks Like
Heart rate data gives you something feel never can: an objective record of what your body is actually doing. Over time, that record tells you whether your easy days are actually easy, whether your hard days are producing the stress that drives adaptation, and whether your recovery is real or just the absence of soreness. Runners who train and race with both inputs see their improvements much more easily.
At almost every race I’ve run, the first quarter mile is a trap. Other runners surround you, the energy is high, and the effort hasn’t landed yet. HR is still low, the pace feels easy, and your body is telling you everything is fine. I learned early to check my watch in that first quarter mile, regardless of how I felt, because every time I trusted the ease and pushed through, I blew up before mile one was done. Sometimes the pace was entire minutes faster than it should have been to carry me the whole distance, and my body just hadn’t caught up yet. The feel was real. It was also completely wrong about what was sustainable at that point in the race.
The flip side shows up in training data. A runner I know was building toward a marathon, felt strong through a 10-mile long run, and came away confident. When we looked at his data together, the first seven miles were steady. Then pace started dropping in the last three miles while HR pushed up into high zone 4. He felt strong and steady because he was working hard enough to feel in control. The data showed a system that was starting to come apart. If that run were 16 miles instead of 10, he would have hit his wall well before the finish. Feel told him the run went well. The data showed him where his marathon would end.
How to Use Both in a Single Training Run
Before you start, check your resting HR if you track it. If your resting HR is more than 5 to 7 beats above your normal baseline, your body is signaling something before you’ve taken a step. It doesn’t mean you don’t run - it means you go in knowing your system is already strained and adjust your targets accordingly.
During the run, use both feel and HR as a cross-check. When they tell the same story, you’re getting a clear picture. When they diverge, something is happening worth paying attention to. If HR is high and pushing into upper zones or past thresholds, but effort feels manageable, your body is under more physiological stress than it’s registering by feel alone - heat, drift, or fatigue are likely driving the number up. Back off regardless of how you feel. If effort feels harder than the HR warrants, you may be under-fueled, mentally fatigued, or early in a recovery deficit. Read both inputs and adjust based on what your training goals are for that session.
In the second half of a long effort, lean toward HR. Cardiac drift is most likely distorting perceived effort late in a run. If HR is climbing but effort feels steady, your body is working harder than it feels. Pull back pace or fuel more to manage energy demands.
On race day, know that RPE will be suppressed at the start. The first miles will feel easier than they are. Let your training data govern your strategy. Once you’re a few miles in and adrenaline settles, you’ll have both inputs to get real-time reads on how you’re performing.
The runner who called me out wasn’t completely wrong. Feel is a real skill, and it matters. What they didn’t have was the other half of the picture - the part that catches what feel misses, confirms what feel gets right, and tells you what’s actually happening when your body says one thing and the data says another.
When your watch and your body disagree on a run, which one do you trust - and do you actually know why?