Your strength isn't random.It moves with your cycle.

It's an active area of research, and we'd rather be straight with you than oversell it. Some studies find higher strength in the follicular phase, some find the opposite, and plenty find no difference at all — the honest summary is that the group-average effect is small and still debated. What isn't debated is how much this varies between individuals: two women with the same cycle length can have completely different weeks. That's exactly why Phase doesn't just hand you a generic 28-day template. It logs your sessions and symptoms, learns from your own RPE, and shows you your own pattern — and if your strength turns out not to track your cycle, the chart will show you that too.

Because they can't see half of what's driving your training. Phase does the same job — sets, reps, RPE, plate math, rest timer, PR detection, e1RM trends — and adds the layer they're missing. Two honest caveats. There's no way to import your training history yet, so you'll start fresh from your current working weights (your cycle does import from Apple Health). And the pattern takes real time to emerge: your chart is phase-coloured from the first few sessions, but Phase won't tell you something like "your squat averages 7% higher in your follicular phase" until it has around eight sessions of that lift in each phase — usually three to four months of consistent logging.

The annual plan starts with a free week, so you can log real sessions before you pay anything. After that Phase is a subscription — monthly or annual, with current pricing shown on the App Store — and there's no permanently free tier. In exchange there are no ads, no trackers, no data harvesting and no upsells; the subscription is the entire business model, which is also why we have no reason to collect your data. Cancel any time from your Apple account settings.

No. Phase reads your cycle from Apple Health, so you keep logging periods wherever you already do. If you don't use Apple Health, you can log your cycle directly in Phase instead.

Completely. Everything lives on your iPhone and in your own private iCloud. There are no accounts, no ads, and no analytics — we don't have a server that could ever leak your data.

Phase learns from the cycles you log and widens its estimates when your cycle is variable. On hormonal birth control, it switches to honest, standard progression instead of faking phases.

Yes — but smarter, not harder. In the luteal phase recovery often dips and PMS can sap drive, so Phase automatically shifts your routine toward moderate volume and technique work instead of max-effort lifts. You keep training and logging; the app just stops asking for PRs when your hormones aren't there.

No — Phase is a full iPhone app. But if you have an Apple Watch, you can start a session, log every set, and run your rest timer from your wrist, all in sync with your phone.

No. Phase provides general training education, not medical advice. Cycle estimates are for planning your training only — never for contraception or family planning.