Running pace guides

These guides explain the numbers behind the calculators. Each one shows its working, cites its sources, says what the evidence does not cover and links to the tool that does the arithmetic.

• How much does heat slow your pace? What research showsWhat marathon studies found as the heat index rises, why the studies disagree and how to plan pace.
• Treadmill vs outdoor running: what the research reviews showWhat systematic reviews found on biomechanics, heart rate and effort, and how to set pace and incline.
• Riegel’s formula: predict race times and find your exponentHow the formula works, how accurate it is, and how to calculate your own exponent from two races.
• Negative splits vs even pacing: what the research saysWhat a pacing review found, plus a worked marathon plan for even, negative and positive splits.
• How to pace a 5KTurn a goal time into pace and splits, with a goal table and the mistakes to avoid.
• Treadmill incline and pace: does 1% match outdoor running?What the 1996 study behind the 1% rule measured, which speeds it covered and what it did not test.
• How to calculate running paceThe formula, worked examples for 5K to marathon, distance conversions and the mistakes that skew your result.

Where to start

• New to pace? Read how to calculate running pace, then try the mile pace calculator.
• Racing soon? Read how to pace a 5K and negative splits vs even pacing.
• Setting goals? Read Riegel’s formula and your personal exponent, then use the race time predictor.
• Running on a treadmill? Read treadmill incline and pace and treadmill vs outdoor running.

Topics covered

• Pace basics. What pace and speed are, how to convert between miles and kilometers and how to avoid common arithmetic mistakes.
• Racing. How to turn a goal time into splits, and what research says about even pacing and negative splits.
• Prediction and training. How race time prediction works, where it runs fast and how to find your own exponent.
• Treadmill running. What the research says about incline, heart rate, effort and how outdoor and treadmill running compare.

How the guides are written

Each guide starts with a direct answer, shows the formula or evidence, and ends with a list of sources. Studies are described for what they measured, including their limits, and practical advice that is not backed by a study is labeled as practical. Numbers in tables come from the same tested code as the calculators. See the methodology and the author page.

Looking for a calculator instead? See all running pace calculators.