KAYN
A kettlebell, a resistance band and a cushion on a bare floor in low light.

KAYNTraining app for tennis athletes

Your session doesn't exist until you ask for it.

The training app for tennis athletes. Every session built from your readiness, your time and your coach's plan.

Read at every check-in ReadinessMental stateTime availableEquipmentSoreness by areaMatch statusCoach directives

01Why the old way fails

Your plan was written before your week happened.

For a player whose week is decided by a draw sheet, a fixed programme is out of date the moment it is printed.

01Written in advance

A programme is authored weeks before you train it. It cannot know the draw, the surface you ended up on, or the three-setter you played on Saturday.

02Written for somebody else

Templates come from a body that is not yours. Same sport, different morphology, different demands, different things that go wrong.

03Edited, never rebuilt

When the day does not match the page you drop a set and carry on. The plan never changes. You absorb the difference.

02What adaptive actually means

Customised is not adaptive.

Customised means your name on somebody else's template. Adaptive means nothing exists until you ask — and then it is built from the day you actually turned up with.

Generic strength work does not just miss. It costs.

Your body is already trained. Work that ignores what tennis demands adds fatigue without adding capacity.
KAYN
Engine active
your check-inEnergy · Soreness · Gear
your historySessions · Swaps · Streak
safety checksRecovery · Load limits
readiness metricsHRV · RR · Downshift
coach programmingCoach library · Style
today's focusPhase · Schedule
Reading your check-in
01 / 06

Built on request · every time you train

03Who you are

Nobody moves like you.

Two players of the same standard, on the same day, should not be handed the same work. The engine reads what is permanently true about you before it reads anything else.

Morphology

How your body actually moves

A movement screen run by your coach becomes a standing fact about you. Selection biases toward the patterns you own and away from the ones you do not.

Your backhand

One hand or two

A one-hander loads the wrist, elbow and shoulder on the hitting side, so the work includes eccentric wrist extension, grip strength and thoracic rotation. A two-hander drives from the trunk, so it gets anti-rotation core and hip internal rotation instead.

Your surface

Clay, hard, grass

Clay means sliding and long rallies: hip rotation, oblique strength, hamstring eccentrics. Hard court punishes joints: unilateral knee and hip work, deceleration, ankle stability. Grass is short and explosive: reactive strength, calf and Achilles integrity.

04Where you are today

You are not the athlete you were yesterday.

Same player. Same scheduled focus. Two Tuesdays that have nothing in common, because the days did not.

Scheduled focusUpper strength
Tuesday 1Check-in 06:41
ReadinessFresh
Mental stateClear
Time60 min
EquipmentFull gym
Match statusNo match
Shoulder0 of 10

Full strength, 60 minutes.

Progressive loading. Overhead work included. Short breathing close.

Nothing routed around
Tuesday 2Check-in 07:12
ReadinessStiff
Mental stateWired
Time30 min
EquipmentTwo dumbbells, a band
Match statusTough win yesterday
Shoulder4 of 10

Recovery-shaped, 30 minutes.

Extended-exhale breathing opens it. Low-load movement, aerobic flush.

Routed around · overhead pressing

05The match week

A match week is not a training week.

Most apps treat every day as a chance to train. Around a match, that is exactly the wrong instinct — and it is the week that decides your season.

The day before

Nothing that arrives late

No heavy lower body, no eccentric overload. Soreness that turns up twenty-four hours later is the one thing a session must never cause. It is built as preparation, not as a workout.

Match day

Fifteen minutes, activating

Hip and ankle mobility, light rotational priming, a breath reset. Never fatiguing. You should walk on court more energised than when you started, not less.

The day after

It reads the result

A tough win and a bad loss do not produce the same next day. Won and fresh gets light technical work. Won and sore gets active recovery. Lost and flat gets something else entirely.

A loss is not only a physical cost.

After a heavy defeat the engine front-loads nervous-system work, because the mental hit compounds the fatigue. Very little else in training treats that as a real input.

06Two systems, one engine

The body and the nervous system train together.

An athlete's forearm resting on a loaded barbell in low light.The physical systemFlip

The physical system

Load, volume and intensity move with what your body can handle today — not what the plan assumed last week. Progress keeps compounding.

An athlete breathing through one nostril, eyes closed, in low light.The nervous systemFlip

The nervous system

KAYN reads your readiness signals — sleep, stress, recovery state — and shapes the session before you start, so training works with your nervous system.

07Where you are in the year

The season decides what the work is for.

The same athlete needs opposite things in November and in June. The engine holds the difference so you do not have to remember it.

01Off-season

The heaviest structural loading of the year, at the highest volume. This is when capacity gets built, and the engine takes the whole of it.

02Pre-season

Absolute load comes down. Reactive and power work goes up. Sport-specific movement patterns start priming for competition.

03In-season

Volume drops by a third or more and heavy bilateral work largely stops. The goal is no longer to build. It is to arrive on court intact.

04Tournament Mode

A switch you flip yourself, and it overrides everything the calendar thinks. Sessions cap at twenty-five to thirty-five minutes, structural work stops, and with no gym at the venue the engine builds from a band and your own bodyweight.

Fri24Rest
Sat25Cardio
Sun26Mobility
Mon27Full
Tue28Mobility
Wed29Rest
Thu30Mobility
Full body — hip-stable strength
K
First session with us, so we're keeping it introductory, not intense.
Full gym available, but we build strength steadily, not by testing limits.
You capped time at 15–30 min, so this is a focused 30 for the whole body.
What shaped today
  • Biasing toward hip-stable, core-controlled work.Movement screen
  • You noted a squat limitation, so we picked supported strength.Today's check-in

Your session is ready

~30 min · 3 sections

Rest 90s to keep each set clean and controlled.

A real session · the reasoning is on the surface

08What shaped today

Every session shows its logic.

Each one opens with what the engine considered — your coach's guidance, your movement screen, your day's state. If we cannot explain a decision on the screen, we do not ship it.

01The focus lock

A bad night changes the intensity. It never changes what you're training.

02Area gates

Flag an area as sore and the engine routes around it — or stops loading it entirely and hands the decision to a human.

03The validator

A session that contradicts your schedule or assumes equipment you don't have never reaches the screen.

10Get in touch

Talk to us.

Athlete access, coach and academy partnerships, or press.