Where it stops.
Before any plan exists, CourtFit asks for a pain score from zero to ten and for red flags. A score of 5 or higher, or any red flag — swelling, numbness or tingling, night pain, recent surgery, or a doctor advising against training — blocks plan generation completely. There is no lighter version and no way past it; the only route on is back to the safety check.
Mid-session the same question splits in two. Pain of 5 to 7 with no red flags offers a mobility detour and keeps your streak. Pain of 8 or above, or any red flag, closes the workout.
What flagging it changes.
Below the blocking threshold, declaring the knee as a pain area removes the 11 exercises that load it provocatively — the jumping, the bounding, the hard deceleration drills and the heavy single-leg work. What stays is the low-impact control work: the 21 exercises training balance and ankle stiffness, kept on purpose and moved to the front of the session.
Reporting any pain above zero, in any area, is a separate rule: it removes plyometrics from the week and takes a set off the main work. Those two mechanisms are independent, and a plan can be shaped by one without the other.
What leaves the week.
These are the 11 exercises the app drops while knee is flagged. They are not dangerous movements — they are the ones that load this joint in the way the screen is trying to spare.
Split squat
Single-leg strength is what lets you load one leg explosively on the serve and recover from lunging shots.
Skater hop
Mirrors the explosive lateral push and stick of chasing a wide ball and recovering.
Lateral bound
Develops the raw lateral power that gets you to the wide ball a half-step sooner.
Pogo hop
Reactive ankle stiffness is what makes your split-step crisp and your first step quick.
Drop step deceleration
Trains the braking control you need to stop on a dime and change direction without losing balance.
Sled push
Builds joint-friendly leg drive and the repeat power you call on across long rallies.
Couch stretch
Loose hip flexors let you extend the hips fully on the serve and run without tightness.
Adductor rockback
Opens the inner thigh so you can lunge wide for the ball without straining the groin.
Court shuttle template
Directly rehearses the sprint-stop-change pattern that defines movement during rallies.
Lateral shuffle decel drill
Trains the controlled side shuffle and brake you use covering the baseline corner to corner.
Shadow swing conditioning
Conditions you in the exact movement and swing patterns of a point, building match-specific fitness.
The 21 the library holds.
These are the exercises tagged for balance, ankle stiffness and landing control. It is a wider net than the library's legs and hips category, which holds 20 exercises: the app selects on the quality, not the category. Each line is the app's own sentence about what it does for a tennis player — not a claim about your knee.
One honest note: the lower-load set the app keeps for knee is the same 21 it keeps for ankle — the two joints share the same training qualities in the library, so the app draws on the same work for both. What differs is what comes out: 11 exercises here against 6 for ankle.
Agility ladder low-intensity
Sharpens the quick, precise foot patterns that get you set in position for every shot.
Single-leg balance reach
Improves the one-leg balance you need to recover after stretching wide for a ball.
Split-step rhythm drill
Times and sharpens the split-step that launches every reaction to your opponent's shot.
Ankle dorsiflexion mobilization
Better ankle bend lets you load and change direction smoothly without rolling onto the toes.
Band lateral walk
Strong hip stabilizers keep your knees tracking well during the constant side shuffles of a point.
Bear crawl
Builds the coordinated, twist-resisting core that keeps you stable while moving in every direction.
Bird dog
Builds the anti-twist trunk control that keeps your core solid through every stroke.
Calf raise
Strong calves give you the springy, stiff ankles that make split-steps and direction changes quick.
Calf stretch bent/straight knee
Supple calves and ankles move freely for quick footwork and reduce lower-leg strain.
Copenhagen plank regression
Adductor strength helps control the load of wide lunges and open-stance shots.
Cossack squat regression
Builds strength in the deep lateral range you reach on a wide, stretched-out get.
Dead bug
Teaches your core to resist the backward arch used during the serve.
Forward-backpedal change drill
Rehearses the run-in-then-recover footwork you use approaching the net and retreating for a lob.
Goblet squat
Stronger legs mean more force into the ground when you load to serve or chase a wide ball.
Jump rope intervals
Builds the light, springy footwork and repeat-effort fitness you rely on across a match.
Lateral lunge
Trains the lateral push and stick that defines fast, controlled side-to-side footwork.
Reverse lunge
Builds the braking strength you need when a stride takes you past the ball and you have to stop and reset.
Seated calf raise
Builds the endurance calf that keeps your feet lively deep into a long match.
Single-leg RDL
Strong, balanced hamstrings and glutes support forehand rotation and open-stance control.
Step-up
Builds the vertical leg drive that contributes to a higher, more powerful serve.
Tibialis raise
The shin works during hard stops and quick changes of direction.
See the whole library — all 84 exercises, grouped by what they train.
The other four the screen covers.
CourtFit's pain screen asks about five areas, and each one changes the week differently. These are the other four.
Read next
Straight answers.
Can I train with knee pain from tennis?
CourtFit cannot answer that for you — it cannot examine a knee and does not try to. What it does is refuse to build a plan when you report pain of 5 or higher out of ten, or any of its red flags: swelling, numbness or tingling, night pain, recent surgery, or a doctor telling you not to train. In those cases it shows a referral message instead of a lighter week.
Does CourtFit stop me jumping if my knee hurts?
Two rules do that, and they are separate. Flagging the knee removes the 11 exercises that load it provocatively, jumping and bounding among them. And independently of any area, reporting any pain above zero removes plyometrics from the week and takes a set off the main work — so even an unflagged knee gets a week without jumping if you report pain anywhere.
Does CourtFit replace a clinician for knee pain?
No. It is a training companion, not medical care, and it does not diagnose, treat or prevent any condition. If pain increases, stop and consult a qualified healthcare professional.
What if the pain starts mid-session?
The workout screen asks. Pain of 5 to 7 with no red flags offers a mobility detour instead of the loaded session. Pain of 8 or above, or any red flag, ends the session with a referral and no option to continue.