Short definitions of the terms used across the calculators and guides, each with the tool that uses it. Where a number is given, it was computed with the same engine as the tools.
- Age grading
- A way to compare race times across ages and sexes: your time is compared with the best time on record-based standards for your age, and the result is a percentage. 100% means you matched the standard for your age. This site uses Alan Jones's 2025 road tables. See the age grading calculator.
- Cadence
- Steps per minute while running, counting both feet. Count the steps in 30 seconds and double it. See the running cadence calculator.
- Even effort
- Pacing that keeps effort level rather than pace: slower up hills, faster down them, so the energy cost per minute stays about the same. See the course pace planner.
- Even pace
- Running every mile or kilometre in the same time. On a flat course, even pace and even effort are the same thing. See the split calculator.
- Grade-adjusted pace (GAP)
- The pace on flat ground that would cost the same energy as your pace on a slope. Our calculator uses the energy cost of running on slopes measured by Minetti and colleagues (2002). See the grade-adjusted pace calculator.
- Gross and net calories
- Gross calories include what your body burns at rest; net calories leave that out. One MET, 3.5 ml of oxygen per kilogram per minute, is the resting part subtracted for net. See the calories burned calculator.
- Heart rate reserve (Karvonen method)
- Maximum heart rate minus resting heart rate. Training zones set as a share of the reserve, added back to the resting rate, sit higher in beats per minute than the same share of maximum heart rate. See the heart rate zone calculator.
- Interval pace
- In Daniels' bands, a pace at 95 to 100% of VO2 max. See the training pace calculator.
- Lane stagger
- The staggered starting positions in races run in lanes, which make every lane the same distance. Each lane out adds about 7.67 m per full lap (7.04 m from lane 1 to lane 2) under the World Athletics measuring rule. See the track split calculator.
- Marathon pace
- The pace you can hold for 42.195 km. A 4:00:00 marathon is 9:09 per mile or 5:41 per km. See the marathon pace chart.
- MET
- Metabolic equivalent: the energy cost of an activity as a multiple of resting. 1 MET = 3.5 ml of oxygen per kilogram per minute. The 2024 Adult Compendium of Physical Activities lists MET values for hundreds of activities. See the calories burned calculator.
- Negative split
- Running the second half of a race faster than the first. A 1% negative split means the first half takes 1% of the total time longer than the second. See the split calculator.
- Pace
- Time per unit of distance, such as minutes per mile or per kilometre. Pace = time / distance. See the pace calculator.
- Pace band
- A paper wristband listing the elapsed time you should see at each mile or kilometre for a goal finish time. See the pace band generator.
- Positive split
- Running the second half of a race slower than the first. See the split calculator.
- Repetition pace
- The fastest of the training paces. Daniels' bands put it above 100% of VO2 max; this site uses your predicted mile race pace. See the training pace calculator.
- Riegel formula
- Peter Riegel's 1981 endurance formula for predicting a race time from another: T2 = T1 x (D2 / D1)^1.06, with 1.06 the popular exponent. A 20:00 5K predicts 41:42 for 10K. See the race time predictor.
- Speed
- Distance per unit of time, such as miles per hour. Speed in mph = 60 / pace in minutes per mile: 8:00 per mile is 7.5 mph. See the pace converter.
- Split
- The time for one segment of a run or race, such as a mile, a kilometre or a 400 m lap. See the split calculator.
- Step length and stride length
- Step length is the distance from one foot landing to the other foot landing; a stride is two steps. Speed = cadence x step length. See the stride length calculator.
- Sweat rate
- How much fluid you lose per hour of exercise, measured from body weight before and after, plus what you drank, minus urine. See the sweat rate calculator.
- Taper
- The reduction in training before a race. A 2007 meta-analysis by Bosquet and colleagues found the best results from about two weeks with volume cut 41 to 60% while intensity and frequency were kept. See the taper calculator.
- Threshold pace
- In Daniels' bands, a pace at 83 to 88% of VO2 max. See the training pace calculator.
- VDOT
- Jack Daniels' term for a VO2 max value estimated from a race performance with the Daniels and Gilbert (1979) equations. A 20:00 5K gives a VDOT of about 49.8. See the training pace calculator.
- VO2 max
- The highest rate at which your body can use oxygen, in millilitres per kilogram per minute. It can be measured in a laboratory or estimated from field tests such as the Cooper 12-minute run. See the VO2 max calculator.
- Watts per kilogram
- Cycling power divided by body weight, the figure riders use to compare climbing ability. The cycling calorie calculator shows it for the power you enter.
Sources: Riegel (1981), Athletic records and human endurance, American Scientist 69(3); 2024 Adult Compendium of Physical Activities. Rules checked . Found a problem? Tell us.