Fitness & Training
Twenty tools for people training for something specific. Pace, load, splits, fuelling and recovery — the arithmetic between a session plan and what actually happened, worked out rather than felt.
20 tools in Fitness & Training
- Running Cadence CalculatorSteps per minute from a count and a stopwatch, with the stride length that cadence implies at your pace.
- Calorie Burn EstimatorEnergy cost of an activity from its published MET value, your mass and the duration, cited to the Compendium of Physical Activities.
- Training Heart Rate ZonesFive training zones from a measured or estimated maximum, and why the age-based formula everyone quotes is the weakest input available.
- Powerlifting Score CalculatorCompare lifts across body weights with the coefficient that replaced Wilks, so a lighter and a heavier lifter can be ranked together.
- Macro Split CalculatorTurn a daily calorie target into grams of protein, carbohydrate and fat at a ratio you choose, with the per-gram figures shown.
- Marathon Finish PredictorProject a marathon time from a shorter race using Riegel and Cameron, and see why both overpredict for anyone undertrained at distance.
- One-Rep Max CalculatorEstimate a single-rep maximum from a set you actually completed, using several published formulas at once because they disagree more than lifters expect.
- Pace Unit ConverterMove between minutes per kilometre, minutes per mile, kilometres per hour and miles per hour without doing it on a phone keypad.
- Barbell Plate LoadingWhich plates to put on each side for a target weight, in kilograms or pounds, and the nearest total you can actually make.
- Cycling Power to WeightWatts per kilogram from a power figure and body mass, with the climbing speed that ratio implies on a given gradient.
- Protein Target CalculatorA daily protein range for your mass and training goal, quoted from published position stands rather than from a single round number.
- Race Split PlannerTarget splits for every kilometre or mile of a race, even or progressive, so you know the number to check your watch against.
- Rest Interval TimerA countdown between sets that keeps running when the screen dims, with the rest lengths different training goals are built around.
- Running Pace CalculatorPace, time or distance from the other two, in minutes per kilometre and per mile, with the splits you would need to hold it.
- Step to Distance ConverterTurn a step count into distance using your own stride, measured from a walked test rather than assumed from your height.
- Sweat Rate CalculatorLitres lost per hour from your mass before and after a session and what you drank, which is the only way to know your own number.
- Swim Pace ConverterConvert between pace per 100 metres and per 100 yards, and work out interval times for a set from a target pace.
- Taper Schedule PlannerWind training volume down before a race across a chosen number of weeks, holding intensity while the mileage falls.
- Training Load TrackerSession load from duration and perceived effort, plus the acute-to-chronic ratio and why that ratio is disputed evidence rather than a rule.
- VO2 Max EstimatorEstimate aerobic capacity from a timed effort or a resting pulse, with the population the formula was derived in stated.
Four things a training week is made of
The category divides by what you are trying to control, not by sport. Most people will use tools from two of these four groups and never open the others.
- Speed and distance: running, swimming and cycling paces, cadence, step length, race splits and a finish prediction.
- Load: one-rep max, plate loading, a powerlifting score that makes lifters of different bodyweights comparable, and a training load tracker.
- Physiology: an estimated VO2 max, heart rate zones, calorie burn and sweat rate.
- Fuelling and recovery: protein target, macro split, rest intervals between sets, and a taper before a race.
Where the published equations disagree, and why that is shown
Sports science does not hand out one formula per question. It hands out several, fitted to different groups of people at different times, and they disagree by amounts that change what you would do. Hiding that behind a single number is the standard failure of a fitness calculator, and it is avoided here by naming the equation and, where it matters, printing what the alternative would have given.
Maximum heart rate is the clearest example. The familiar 220 minus age and the Tanaka equation differ by four beats at 52 and by nine at 70 — and every zone boundary in the table moves with them. So the heart rate tool computes with Tanaka, says that it did, and shows what the other equation would have produced at the same age. A measured maximum, if you have one, beats both and is offered first.
One-rep max is the same shape of problem, and the tool answers it by running Epley, Brzycki, Lombardi and O’Conner together rather than picking a winner: the spread between them at your rep count tells you how much confidence the estimate deserves, which a single figure cannot.
A prediction is only valid over the range it was fitted to
The marathon predictor uses Riegel’s equation, and it enforces Riegel’s own stated range: events of roughly three and a half minutes to three and a half hours. Outside that the tool says so instead of extrapolating quietly. It is also honest about the well-known weakness — the equation is well calibrated up to the half marathon and tends to be optimistic about the full one, because a marathon is limited by fuelling and durability in a way a 10K is not, and no exponent can encode that.
That is the general rule across this group. A formula is a summary of a data set, so a figure produced far outside that data set is an extrapolation wearing the clothes of a calculation, and the pages here mark the boundary rather than blurring it.
Which tool for the session you are planning
- Running Pace Calculator
- A pace, a time or a distance when you have the other two.
- Race Split Planner
- A target time broken into the splits you will actually run to.
- Training Heart Rate Zones
- Zone boundaries from a measured maximum, or from a named age equation.
- One-Rep Max Calculator
- An estimated single from a set you completed, across four published formulas.
- Sweat Rate Calculator
- How much you actually lose in a session, from before-and-after weights.
- Taper Schedule Planner
- The final one, two or three weeks before a race, planned rather than improvised.
Two questions from people who train
Should I use my measured max heart rate or the age formula?
The measured one, every time, if it came from a genuine maximal effort rather than from the highest number your watch has ever displayed. Age equations are population averages with a wide spread around them, and an individual can sit fifteen beats either side of the prediction without anything being wrong.
Why is my predicted marathon time faster than anything I could run?
Because the equation only knows one thing about you — a shorter race result — and a marathon is limited by fuelling, pacing discipline and how much long running you have done, none of which appear in the input. Riegel is a strong predictor up to the half marathon and an optimistic one beyond it, and the tool says so on the page rather than leaving you to find out on the day.