Frequently Asked Questions

The best workout app for adapting to your performance is one that uses real data from your actual sessions — not a questionnaire at signup — to adjust your training over time. The Hypertrophy Lab is designed specifically for this: after every workout, you log your sets and rate your effort using RIR (Reps in Reserve), and the system uses that data to adjust your volume, load targets, and exercise selection in upcoming sessions. It also detects patterns across multiple weeks — progression, stagnation, fatigue accumulation — and adjusts the program accordingly. No manual editing required.

Most workout programs stop working because they're static — the sets, reps, and weights don't change based on how you're actually responding to training. Two lifters doing the same program can have completely different outcomes, because individual responses to training volume, exercise selection, and intensity vary significantly. Once your body adapts to the stress a static program applies, it has no reason to keep growing. The solution is a program that tracks your data and adjusts: if you're responding well, it adds volume; if you're accumulating fatigue, it reduces it or triggers a deload. That's what The Hypertrophy Lab does automatically.

The right time to increase weight is when you're completing your target reps with more reps in reserve (RIR) than prescribed — meaning the weight has become easier than intended. For example, if your program targets RIR 2 and you're finishing sets at RIR 4 consistently, it's time to add weight. The Hypertrophy Lab tracks your estimated one-rep max (E1RM) across sessions and monitors your RIR feedback. When your performance data shows you're handling load with more ease than the program intends, the system adjusts your load targets upward automatically — so you don't have to guess.

A regular workout program prescribes the same sets, reps, and weights for everyone, following a fixed schedule regardless of how training is actually going. An adaptive program uses your performance data — workout logs, effort ratings, fatigue reports — to adjust what comes next. Volume increases when you're recovering well and responding strongly. Volume decreases when fatigue is accumulating. Deloads trigger when your data shows they're needed, not because it's week 8. The Hypertrophy Lab implements this automatically: every session you complete gives the system more signal to work with, and your program evolves based on your specific response patterns.

Yes — and it's where the app delivers the most value. Adaptive programming provides the greatest return on investment for intermediate and advanced lifters, because individual variation in training response becomes more pronounced with training experience. Beginners respond well to almost any structured program. Intermediate and advanced lifters have accumulated enough history that generic programs often stop producing consistent results — which is exactly when a system that tracks your data and adapts to it becomes essential. That said, committed beginners can use the app too; it adjusts volume rules based on experience level.

Hypertrophy just means making your muscles bigger. When you lift weights, you stress the muscle. When you rest, the body repairs it slightly stronger and thicker than before. Do that consistently — and push a little harder over time — and the muscle grows. That's the whole idea behind this app: train hard, recover well, and keep progressing.

RIR stands for Reps In Reserve — how many more reps you could have done before reaching failure. An RIR of 2 means you stopped with 2 reps left in the tank. This autoregulation method lets the program adapt to your actual performance rather than prescribing a fixed number of reps.

A Training Block (mesocycle) is a multi-week training plan organized into daily workouts. Each block has a set number of weeks and training days per week. You can view all your blocks on the Training Blocks page, and activate one to make it your Current Block.

On the landing page, click Sign Up and enter your first name, email address, and a password. Alternatively, you can sign in with an existing account via the Sign In link. After submitting, you'll be taken directly to the onboarding flow.

Onboarding has four quick steps: (1) your training experience level, (2) your primary goal (hypertrophy, strength, or recomp), (3) your sex, and (4) your bodyweight in lbs. These inputs inform the AI when generating and adjusting your program. You can update all of these later in Settings.

Click Generate in the sidebar. Select your sex, set the days per week you can train, the program length in weeks, assign muscle priorities (Primary, Secondary, or Maintenance), and choose your training focus. Hit Generate Program — the AI will build a full periodized block, and you'll be taken to the Training Blocks page when it's ready.

To get the best program, be clear and specific about your goal, priorities, and constraints. Tell the AI what you want to focus on (e.g., quads and calves), how often you train, your experience level, and any limitations. The AI uses this information to build a structured, evidence-based plan. Vague inputs lead to generic programs, while clear inputs produce more accurate, personalized results. If something feels off, refine your inputs rather than starting over.

On the Training Blocks page, open your active block and click the day's workout. You'll be prompted with a pre-session check-in (soreness, sleep, energy, nutrition) — answer honestly, as these influence AI feedback. Then log each set's weight and reps as you complete them.

In the workout view, each exercise card has input fields for pounds (LBS) and reps per set. Enter your values and hit the checkmark button. The set logs immediately and the rest timer starts automatically.

After logging any set, a floating rest timer appears at the bottom of the screen. Tap it to expand and choose a preset duration (1:00, 1:30, 2:00, 2:30, 3:00, or 5:00). The timer pulses red in the final 10 seconds. You can stop or reset it at any time.

The Finish Session button is only active once every set across every exercise has been logged. If sets are still remaining, the button shows how many sets are left. Once all sets are done, click Finish Session to complete a post-workout debrief, which the AI uses to adjust your next session.

Yes. On any active workout, each exercise card has a Skip Exercise link at the bottom. Tapping it removes the exercise from the current session without affecting the rest of your program. Use this for injury, equipment availability, or time constraints.

Yes. While a workout is active, tap the + Exercise button in the header to add any exercise from the library. To swap an existing exercise, tap the info icon (ⓘ) on its card and use the Swap This Exercise section to find a replacement. Swapping keeps the same sets, reps, and RIR targets.

The Lab Coach is available on any active workout via the chat bubble in the bottom-right corner, and also as a standalone page (Lab Coach in the sidebar). Ask it anything: form cues, load adjustments, substitution ideas, programming questions, or general training advice. It has full context of your current workout.

After each session debrief, the AI reads your RPE, fatigue rating, difficulty perception, and notes. It compares these against your targets and may increase or decrease volume and load for your next session. You'll see a summary of what changed after submitting your debrief.

Go to Settings in the sidebar. You can update your goal, experience level, sex, and bodyweight at any time. Changes take effect on the next AI interaction or program generation.

You can generate multiple blocks, but only one can be active at a time. Your active block appears as a Current Block shortcut in the sidebar with a pulsing indicator.

The Library page (Dumbbell icon in the sidebar) lists all exercises available in Hypertrophy Lab, with muscle group filters. You can browse these to plan your next program or find swap options during a workout.

RIR accuracy takes practice. A reliable cue: at your true 2 RIR, the bar or weight is slowing noticeably and you'd need to concentrate hard to squeeze out another rep. At 0 RIR (failure), you cannot complete the next rep with good form. To self-calibrate, pick a weight and push to actual failure once — note what 1 RIR felt like in hindsight. A simple recalibration rule: if you logged 3 RIR but missed reps on the very next set with the same weight, your RIR estimate was too high — recalibrate down by 1–2 next time. Beginners consistently overestimate RIR; when in doubt, assume you have one fewer rep left than you think.

For hypertrophy, aim for a 2–6 second eccentric (lowering/stretching) phase and a 1-second pause at the bottom stretched position before initiating the concentric (lifting) phase. Example: on a dumbbell fly, take 3 seconds to lower the weights out and down toward chest height, pause briefly with your pecs fully stretched, then press back up with control. You don't need to count out loud — just move slowly enough that you feel the muscle stretch and avoid bouncing at the bottom.

Spending more time under tension in the lengthened (stretched) position is where the greatest hypertrophic stimulus occurs — research consistently shows that the muscle is most mechanically loaded when long. Slowing the eccentric phase also dramatically reduces injury risk: rapid, ballistic loading at the bottom of a rep (e.g. bouncing at the bottom of a fly or squat) puts enormous stress on connective tissue and the passive structures of a joint. A controlled tempo lets you feel the muscle working, use heavier loads safely over time, and accumulate more effective reps per set.

Lengthened partials are reps performed only through the bottom portion of the range of motion — the part where the muscle is most stretched. Instead of doing a full curl from full extension to full flexion, you would repeatedly lower the dumbbell to arm extension and lift only halfway up, staying in the stretched half of the movement. Research suggests this range produces comparable or superior hypertrophy to full reps because peak mechanical tension occurs in the stretched position. Lengthened partials are especially useful as a technique at the end of a set after full reps become impossible: grind out 2–4 partial reps in the bottom range to extend effective stimulus without increasing injury risk.

Myo-reps are a set structure designed to accumulate a high number of effective (close-to-failure) reps while minimizing total time and fatigue. Here's how they work: (1) Activation set — perform 12–20 reps stopping at around 3 RIR. (2) Rest — take 3–5 slow breaths (roughly 20–30 seconds). (3) Mini-clusters — do 3–5 reps, rest 3–5 breaths again, and repeat until you reach failure within a cluster or cannot hit the minimum reps. Each mini-cluster should bring you very close to or at failure. The logic: the activation set pre-fatigues the muscle so that each subsequent cluster, despite being short, is fought at near-maximal effort — generating effective reps very efficiently. Myo-reps work best on isolation movements (curls, laterals, leg extensions) and are a great time-saving alternative to multiple straight sets.