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 lower back as a pain area removes the 11 exercises that load it provocatively — the loaded rotation, the throwing work and the heavy carries. What stays is the work that teaches the trunk to resist movement rather than produce it: the 12 exercises training anti-rotation, anti-extension and posterior chain. Those are 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 lower back is flagged. They are not dangerous movements — they are the ones that load this joint in the way the screen is trying to spare.
Hip thrust
Powerful glutes extend the hips fast, which is the engine behind your serve and explosive first step.
Cable chop
Mirrors the hip-led rotation that drives pace on your forehand and serve.
Cable lift
Trains the upward rotational drive that takes your racket up and through the serve.
Half-kneeling cable lift
Isolates the trunk rotation of the serve so you learn to turn from the core, not the lower back.
Med ball rotational throw
Directly rehearses the explosive hip-and-trunk rotation that powers your groundstrokes.
Med ball scoop toss
Builds the upward rotational snap that helps generate topspin and lift on aggressive groundstrokes.
Med ball slam
Trains the overhead-to-down power sequence that resembles snapping into a serve.
Suitcase carry
Anti-tip core strength stabilizes your trunk during one-handed swings and helps your grip endure.
Farmer carry
Builds the durable grip and posture that keep your racket hand strong late into a match.
Hamstring floss
Mobile hamstrings let you bend for low balls and sprint without tightness.
Medicine ball serve rhythm drill
Grooves the leg-trunk-arm chain of the serve while building repeatable power under light fatigue.
The 12 the library holds.
These are the exercises tagged for anti-rotation, anti-extension and posterior chain. It is a wider net than the library's core and rotation category, which holds 16 exercises: an exercise filed under legs can still train the same trunk-control qualities, and 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 back.
Bird dog
Builds the anti-twist trunk control that keeps your core solid through every stroke.
Band row
A portable way to build the back strength that keeps your shoulders balanced and your backhand solid.
Bear crawl
Builds the coordinated, twist-resisting core that keeps you stable while moving in every direction.
Cable row
Builds the pulling strength and posture that support backhand drives and a balanced shoulder.
Dead bug
Teaches your core to resist the backward arch used during the serve.
Front plank
A stiff core transmits force between your legs and racket instead of leaking it through your spine.
Glute bridge
Teaches your glutes to fire on hip extension, the same drive that pushes you up into a serve.
Hollow hold regression
Builds front-core tension against the backward arch used during the serve.
Pallof press
Resisting rotation builds the control that lets you brake your trunk precisely after a big swing.
Side plank
Strong obliques stabilize the trunk through the sideways forces of groundstrokes.
Single-leg RDL
Strong, balanced hamstrings and glutes support forehand rotation and open-stance control.
Tall-kneeling anti-rotation press
Teaches the core alone to resist twisting forces, sharpening control through your strokes.
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 lower back pain from tennis?
CourtFit cannot answer that for you — it cannot examine a back 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.
What changes in the plan when I flag my lower back?
The 11 exercises that load the back provocatively come out of the week — loaded rotation, throwing and heavy carries among them — and the 12 anti-rotation, anti-extension and posterior-chain exercises are kept and moved to the front of the session. Separately, reporting any pain above zero removes plyometrics from the week and takes a set off the main work.
Does CourtFit replace a clinician for lower back 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.