Parameter vs LiftDiff

Parameter is a workout app built around a simple idea: you already have a subscription to an AI that is a smarter coach than any fitness app's built-in one. Connect it once, and your AI plans your training using your goals, your equipment, and your real workout history, not a generic template. Parameter's job is to run what your AI writes and log it honestly: strength, intervals, classes, and rest, tracked on iPhone and on Apple Watch. In a chat with your AI, you can ask things like: - "Plan my week. I'm training for a 10K in six weeks and I lift Tuesdays and Thursdays." - "I tweaked my knee. Adjust today's session." - "Look at last month and tell me if my squat is actually progressing." Your AI reads your profile, equipment, and history to answer, then pushes a plan or an updated workout straight into Parameter. You never touch a template or a spreadsheet, and Parameter never writes a plan on its own. Parameter runs four kinds of training: guided classes you follow in another app, structured intervals with a live segment display and heart-rate-zone targets, exercise routines with a plate calculator and your last set shown before you lift, and simple sessions for a run, ride, or walk with indoor/outdoor tagging. Rest days get their own card, with active-recovery guidance, not an empty gap in your week. On many machines that support the Bluetooth FTMS profile, Parameter sends each segment's authored targets to the equipment. On heart-rate-zone segments it also closes a loop to hold your zone, correcting speed on a treadmill and power on an indoor bike. It never chases your heart rate with incline. Starting and stopping a machine is always yours. Every interval workout also prints as a numbered console table, so a machine with no Bluetooth at all is still a first-class way to train. Parameter's Apple Watch app works fully on its own, with its own sync, so a run or a lift is tracked wrist-only if that is all you bring. Whichever device starts a workout, the other shows the exact same execution screen, not just a status line, and pause, skip, end, and adjust all work from either wrist or phone. The Digital Crown adjusts your current target or your reps before you check off a set, and watch face complications and a Smart Stack card show what's next. $1 a month, with a two-week free trial, is the only thing Parameter charges for, and it covers only the AI connection. Planning, execution, history, and a full data export stay free whether you subscribe or not. There's no Parameter account: your workouts, profile, and history live in your own private iCloud, and Parameter runs no database of its own to store them in. Parameter works with any MCP-compatible AI client, including the assistants most people already subscribe to. Parameter requires an iPhone running iOS 17 or later. An Apple Watch is recommended for live heart rate and wrist execution, but not required. Having a plan written by your AI needs an MCP-compatible AI client; building and logging your own workouts by hand works with no AI client at all. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://parameterfit.com/legal/privacy-policy/

Simplified gym log. ■ Press. Slide. Logged. Hold the start button and your routines fan out under your thumb. Slide onto the one you came here to do — one thumb, one motion, from anywhere in the app. Favorites sit closest to your thumb, and you can start empty and add exercises as you go. ■ Lift more. Tap less. The set ends, the timer starts, and you put the phone down. Rest runs in the Dynamic Island and on the Lock Screen — never unlock to check it, and never open the app to start the next set. Complete a set from the Lock Screen, or expand for the next exercise, sets left, and time remaining. ■ See where the load landed. Every set you log feeds a per-muscle recovery estimate, drawn on a body map. Not a single "readiness" number — seventeen muscles, each decaying at its own rate. Which muscle is most fatigued is reasonably reliable. How fatigued it is — the absolute number, the percentage — is a rough guide only. Sleep, nutrition, stress and age are not part of this calculation. ■ Week by week, exercise by exercise. See your progress, not just your logs. Every week is diffed against the one before it, and what moved is marked ++ or −. Every exercise keeps its own estimated 1RM, top weight and volume over time, with every set you have ever done under the chart. ■ Friends. Share only a summary of the workout you finished. Friends see that you trained, how long, how many sets, and which muscles — exercise names and weights only if you choose to include them. Your actual records, the sets and the notes, never leave your device. Per-exercise rankings — estimated 1RM, top weight, and sets this week — let you line up against friends who train the same lift. ■ Import anything. Export everything. Bring your history in from anything — another app's export, a spreadsheet, your own notes. Strong and Hevy CSVs import directly. For anything else, the app hands you a prompt that converts it, and RPE becomes RIR on the way in. Take it back out as JSON or CSV, as a file or straight to the clipboard in one tap. RIR, notes and warm-up sets all survive the round trip. It is one SQLite file on your device, with no third-party analytics SDKs. The schemas are public, so anything can read it. Including you. liftdiff.history/v1 · liftdiff.routine/v1 ■ The essentials. ・175 exercises ・RIR & RPE ・Supersets ・Warm-up & drop sets ・Plate calculator ・Rest timer ・Home Screen widgets ・Shareable images ・Per-muscle set counts ・Custom exercises ・Short-version routines ・Favorites ・iCloud sync ・English & 日本語