Training calculators

Training zones from your own test, not a formula

Nine free calculators built by the HP3 coaching team. Each one turns a field test you can do this week into the paces, powers, heart rates, lifting loads and fuelling targets we prescribe to the athletes we coach.

A calculator is only as good as the test behind it. HP3 is a team of chartered physiotherapists and coaches, so every tool here tells you how to run the test properly, what the number can and cannot tell you, and which published method it comes from. The methods and the papers are listed further down this page.

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An athlete running on a treadmill in the exercise physiology lab, wearing a gas-analysis mask, with live oxygen and heart-rate data on the screen beside them

Why zones

Test it, then train to it

Every zone on this page is a percentage of a threshold you measured yourself. That is the point of the tests: a number from your own body on a given day, rather than a chart built from someone else’s age or a race you have not run yet. It is also the limit of the tests, and we would rather tell you that here than let you find out in a session.

01

Field tests stand in for the lab

Lactate threshold is measured with blood samples on a treadmill or ergometer. For most athletes that is neither practical nor necessary. A 30-minute all-out run estimates both the speed and the heart rate at threshold closely enough to prescribe training from, and 95 per cent of a 20-minute cycling effort is a valid field marker of threshold power in trained riders.

McGehee et al. 2005, J Strength Cond Res; Valenzuela et al. 2018, Int J Sports Physiol Perform.

02

Zones move, so re-test

Each calculator anchors its zones to the threshold you enter. Train well for a block and the threshold rises; get ill, injured or take a break and it falls. The zones only stay honest if the number behind them is current, so repeat the test when your fitness changes and re-enter the result. Coached HP3 athletes have this built into their plan.

03

Honest about the error

Field estimates work on average, not perfectly for everyone. In trained cyclists, 95 per cent of 20-minute power matched true hour power as a group, yet an individual rider could be 40 to 60 watts out either way. Treat your zones as a well-founded starting point, watch how sessions feel against them, and adjust. That judgement is what a coach adds.

Borszcz et al. 2018, Int J Sports Med.

The calculators

Nine tools, one place

Five set training zones for swimming, cycling and running. One sets your lifting loads. Three plan fuelling and hydration. Each opens on its own page with the test protocol, how to read the result and the references, so you can check our working.

A swimmer in a wetsuit mid-stroke in open water, hills behind

Swim zones

Critical swim speed (CSS)

You need: your best 400 m and 200 m times from one session. Returns your CSS pace and five pace zones.

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A road cyclist climbing a mountain pass, a lake and peaks in the valley behind

Bike zones

Functional threshold power (FTP)

You need: average power from a 20-minute test, or from both efforts of a 2 x 8-minute test. Returns FTP and five power zones.

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Three runners racing side by side on a tree-lined road, in black and white

Run zones

Threshold pace

You need: average pace from a 30-minute time trial, or a recent 5 km or 10 km race. Returns pace zones per mile or per kilometre.

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A triathlete on a time-trial bike cornering on the Estoril circuit

Bike zones

Threshold heart rate, bike

You need: average heart rate from a 20-minute maximal ride. Returns heart-rate zones for the bike.

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An athlete crossing the Ironman Portugal finish line at night, arms raised

Run zones

Threshold heart rate, run

You need: average heart rate from the final 20 minutes of a 30-minute maximal run. Returns heart-rate zones for running.

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An athlete at the bottom of a loaded deadlift in the gym, a coach watching the lift

Strength

One-repetition maximum (1RM)

You need: a weight you lifted and the reps completed to failure (1 to 10). Returns an estimated 1RM and loads at 50 to 90 per cent.

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An ultrarunner with poles coming through winter woodland on the Spine Race

Fuelling

Ultramarathon nutrition plan

You need: body mass, start time, expected duration and your planned hourly intakes. Returns an hour-by-hour plan for a single-stage ultra.

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A trail runner seen from behind, soft flasks and gels in the belt, moorland beyond

Fuelling

Carbohydrate fuelling

You need: body mass, session length and intensity, what you ate, and any gut symptoms. Returns an hourly carbohydrate target and a tolerance log.

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A cyclist drinking from a bottle, silhouetted against a bright sky

Hydration

Sweat rate and hydration

You need: body mass before and after a session, fluid drunk, duration and conditions. Returns sweat rate in litres per hour and a fluid plan.

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The calculators are free to use and nothing is stored. They give general training guidance, not medical advice: if you have a heart condition, are returning from illness or injury, or are unsure whether a maximal test is safe for you, speak to a clinician first. Our physiotherapists can assess that as part of coaching.

How they were built

Methods you can check

Each calculator uses a published protocol or a published equation, chosen by the HP3 coaching team because it has been tested against laboratory measures in athletes. The summaries below say what each tool does and where the method comes from. The full references are at the foot of this section, with a link to every paper.

Swim

Critical swim speed

CSS is the slope of the line between two all-out swims, here 400 m and 200 m: the pace the distance-time relationship says you could hold for a long time. It correlates closely with the speed at which blood lactate starts to accumulate, and swimming a little below it produces a steady lactate response. At CSS itself continuous effort is limited to around 20 to 25 minutes, which is why the zones put threshold sets just under it.

Wakayoshi et al. 1992; Dekerle et al. 2010.

Bike

Functional threshold power

FTP is Coggan’s estimate of the power you can hold for about an hour, taken as 95 per cent of a 20-minute test. The calculator also accepts a 2 x 8-minute test at 90 per cent of the mean. The 20-minute method is a valid field marker of threshold in trained cyclists; it tends to underestimate threshold in less-trained riders, and individual error is wide, so zones are a starting point to refine.

Borszcz et al. 2018; Valenzuela et al. 2018.

Run

Threshold pace and heart rate

Both run calculators use a 30-minute maximal time trial: the average pace for the whole effort, and the average heart rate for the final 20 minutes. In competitive runners and triathletes that test estimated both the speed and the heart rate at the lactate threshold without a significant difference from blood-lactate measurement. The bike heart-rate tool applies the same logic to a 20-minute ride.

McGehee et al. 2005; protocol after Friel.

Strength

One-repetition maximum

Rather than lift a true maximum, you lift a lighter load to failure and the calculator predicts 1RM with the Epley or Brzycki equation. Repetition-maximum testing predicts 1RM accurately provided the set is 10 reps or fewer, which is why the tool caps the input at 10. The loads it then lists at 50 to 90 per cent are the ranges we programme from in strength sessions.

Reynolds et al. 2006; Brzycki 1993.

Fuelling

Carbohydrate and ultramarathon planning

The carbohydrate tool gives an hourly target for your session and logs gut symptoms against it, because tolerance can be trained and the gut should be prepared for what race day will ask of it. The ultramarathon planner follows the International Society of Sports Nutrition position stand for single-stage ultras: 150 to 400 kcal, 30 to 50 g of carbohydrate and 5 to 10 g of protein per hour, with 450 to 750 ml of fluid.

Jeukendrup 2014, 2017; Tiller et al. 2019.

Hydration

Sweat rate

Weighing yourself before and after a session, corrected for what you drank, is the simplest and most accurate way to measure whole-body sweat rate. Sweat rate and sweat sodium vary widely between athletes and within the same athlete across intensity, heat and acclimatisation, which is why a measured rate beats a generic drinking plan, and why it is worth repeating in different conditions.

Baker 2017.

References

Every paper below was checked against its publisher record before it was listed. Sample sizes are small in some of the swimming and cycling studies, so treat the field tests as validated approximations rather than laboratory measurements.

Use the numbers

Put your zones to work

A threshold is only useful once it shapes a session. These free resources from the HP3 team show how we build training, fuelling and strength work around the numbers the calculators give you.

Fuel and hydrate

Train and lift

Read the evidence

Next step

The numbers are the start. Coaching is what you do with them.

A calculator gives you a threshold. A coach decides how much time to spend at each zone, when to re-test, and what to change when the plan meets real life, injury or illness. At HP3 that decision is made by a team of coaches and chartered physiotherapists working from your data, so the assessment is built into the plan rather than added on.

Not ready for coaching? Join the TeamHP3 community and ask the coaches about your numbers there.

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