How Do You Feel?

Why Athletes Need Both Data and Perceived Effort to Train Smarter

The Most Important Question in Training: “How Did You Feel?”

I recently listened to a podcast with legendary coach Joe Friel, co-founder of TrainingPeaks and a pioneer in endurance coaching. Back in the 1970s—before GPS watches, power meters, or auto-upload existed—athletes would stop by his running store each week to pick up printed training plans.

His main question about their previous week wasn’t about numbers. It was:

“How do you feel?”

Even today, with more data available than ever, that question remains just as important—and sometimes more revealing than the metrics we obsess over.

Steph feeling good as she starts the bike leg at Ironman Texas!

Why Qualitative Feedback Still Matters in a Data-Driven World

Endurance athletes love numbers. Pace. Power. Heart rate. TSS. Sleep metrics. Fueling metrics. But the comments you leave in TrainingPeaks? The RPE score you choose? The three sentences about how the session actually felt?

That is qualitative feedback. And it fills in crucial gaps that data alone can’t explain.

RPE: The Bridge Between Feeling and Data

Rate of Perceived Exertion takes a subjective experience (“This hurts”) and puts it on a universal scale. It helps quantify a feeling—but it doesn’t replace the deeper context you can include in your workout notes.

The value of qualitative feedback is that it’s not “good” or “bad.”It’s simply your honest experience in the moment. And when you pair that with your metrics, you create a far more complete training picture.

Using Feelings + Data to Track Real Fitness Improvements

Sometimes performance improvements don’t appear first in pace or power—they appear in how your body responds.

Here are common signs of progress you can’t see through numbers alone:

• Running at the same pace and it feels easier.

• Swimming faster splits during VO₂ intervals while suffering the same amount.

• Holding steady power with lower perceived effort.

These internal cues are often your earliest—and most accurate—signals that you’re building fitness.

Why Nutrition Feedback Requires Both Numbers and Feelings

Fueling is an area where athletes often rely too heavily on how something felt without pairing it with data.

For example, If Coach Krista asks how many grams of carbs you took per hour and you answer “enough” or “more than last week,” that’s useless. Fueling requires quantitative precision.

But it also requires qualitative context:

• Did your stomach feel stable?

• How were your energy levels?

• Did you fade at the end?

• Did you feel full, hungry, or nauseous?

  
  

You need both

Matching the carb numbers and how your body reacted. That’s where the breakthroughs happen.

Hard Doesn’t Mean Bad. Easy Doesn’t Mean Good.

Athletes often misinterpret how a workout feels:

• Feeling tired during a hard session? That’s normal.

• Feeling great during an interval designed to hurt? That’s not always a good sign—it could indicate you didn’t execute properly.

Context matters. Data alone can’t give you that context but your notes can.

Note-taking is a Simple Habit That Makes You a Smarter Athlete

Ultimately, the athletes who improve the most over time aren’t always the ones with the best numbers—they’re the ones with the best awareness.

Better notes lead to better decisions.

Better decisions lead to better training.

Better training leads to better performance.

If you want to maximize your training, ask yourself the same question Joe Friel asked athletes 50 years ago: “How did it feel?”

And then write it down. Your future self will thank you.