Why effort beats pace and distance

If you judge your training by how fast or far you went, you’re using a ruler that keeps changing length. Speed and distance feel objective. But the effort behind them swings wildly from day to day.

The same pace costs more on a hot, hilly or sleepless day, and less as you get fitter, so a pace goal is always either unfair or out of date. Sports scientists separate the work you produce from the cost your body pays for it, and in “Internal and External Training Load: 15 Years On” Impellizzeri, Marcora and Coutts set out why the cost is what drives adaptation. Heart rate is the practical way to read that cost. Measured that way, effort is fair between a beginner and an elite runner, it counts a row, a HIIT class and a hike in the same currency, and it raises the bar by itself as you get fitter. It is the same idea Eric Banister put into his training impulse in 1975.

The same pace, a different cost

Heat, humidity, hills, poor sleep, and stress all make the same pace feel much harder. Run your usual route on a hot afternoon and your body works far harder than on a cool morning, for the same time on the clock. Judge yourself by pace and you’ll feel like you’re slipping, even when you’re just battling the conditions.

The reverse is also true. As you get fitter, your normal pace feels easier. To keep improving by the pace ruler, you’d have to keep running faster or farther and reset your goals.

Effort is universal

Sports scientists distinguish between external load, the pace, distance, or power you produced, and internal load, the physiological cost your body paid to produce it. In “Internal and External Training Load: 15 Years On,” Impellizzeri, Marcora and Coutts set out the framework precisely, and what matters here is which one drives the result. Adaptation is caused by the body’s response to the stress, the internal load, not by the external work that provoked it.1 Two runners can produce the same external output and experience entirely different training. So can you, on two different days.

Heart rate is the most practical continuous window into internal load, which is why it’s what ZonePoints scores.

It also levels the playing field. An elite runner at a six-minute mile and a beginner at a twelve-minute mile might be working at the same relative effort. ZonePoints gives them the same reward for the same effort.

Every activity speaks the same language

When you measure effort through heart rate, the activity no longer matters. A hard row, a HIIT class, a steep hike, and a fast run all count equally if they demand the same cardiovascular work. You’re free to cross-train and avoid injury. Every drop of sweat counts toward the same goal.

Built-in progression

Because effort tracks your body rather than your ground speed, it handles progression automatically. As your fitness improves, you have to push harder to reach the same zones. You keep improving without rewriting your targets.

This isn’t a new idea. Eric Banister proposed the heart-rate-based “training impulse” (TRIMP) in 1975 and set it out in his chapter “Modeling Elite Athletic Performance”: session duration multiplied by average heart rate, weighted by an intensity factor derived from athletes’ blood lactate response, so that hard minutes count for disproportionately more than easy ones.2 Because every term is measured on the athlete rather than the ground, the same score means the same thing in any conditions. ZonePoints applies that logic to everyday training instead of elite performance modelling.

The takeaway

Pace and distance punish you for bad weather and reward you for good genes. Effort measures what you actually put in. That’s why ZonePoints scores your heart rate, not your stopwatch.

Go deeper: read why measure training effort.