The coach draws on published research. Here are all studies integrated into the AI coach.
Pelland et al. 2024: Sports Medicine, 67 studies
Training Volume & Hypertrophy
Dose-response relationship: more sets = more growth. Fractional set counting for compounds. 2,058 participants.
Refalo et al. 2023: Sports Medicine, 15 studies · Refalo et al. 2024
RIR & Proximity to Failure
RIR 1–3 builds practically the same muscle as training to failure, with less fatigue.
Schoenfeld & Krieger 2017: J Strength Cond Res
Volume Dose-Response
10+ sets/week/muscle for significantly more hypertrophy than fewer sets.
Schoenfeld et al. 2019: J Sports Sci, 25 studies
Training Frequency
At equal weekly volume, frequency makes little difference. Two sessions per muscle group keep the sets per session manageable.
Schoenfeld et al. 2021: J Strength Cond Res
Rest Periods
Longer rest (2–3 min) for compounds, shorter (60–90s) for isolation for optimal results.
Rhea et al. 2003: Med Sci Sports Exerc, 140 studies
Dose by Training Status
Strength: untrained lifters gained most with 3 sessions per muscle group per week, trained lifters with 2 (4 sets each). The app plans 6 (beginner), 9 (intermediate) or 12 (advanced) direct sets per week for each large muscle group. The legs get this number twice: once for the front of the thighs (e.g. squat, leg extension) and once for hamstrings and glutes (e.g. Romanian deadlift, leg curl).
Recovery: staggered, but not by fiber type
Fiber type does not predict the training response, tested directly in 2020. Our reference values come from practice (abs 30h, arms 48h, chest 56h, legs 60h) and only apply without training data. Otherwise the app calculates from your sets, RIR and age.
App heuristic: no study behind it
Age & Recovery
From age 30, the app plans more recovery: 30–39 +10%, 40+ +10% (beginners +20%).
Pedrosa et al. 2022
Stretch-Mediated Hypertrophy
On the leg extension, loading in the stretched position produced significantly more muscle growth.
Kassiano et al. 2023: Eur J Sport Sci
Stretched vs. Shortened Position
Confirms Pedrosa: stretched position superior for all tested muscle groups.
Fonseca et al. 2014: J Strength Cond Res
Exercise Variation
Rotating exercises between sessions produces more hypertrophy than always doing the same ones.
Simão et al. 2012: Sports Med
Exercise Order
The first exercise of a session gets the most reps and load. The app puts compounds before isolation. Exception: hanging leg raises come first.
App heuristic: no study behind it
Deload on Fatigue
After a longer stretch of training, the coach plans a deload session when your recovery check-in shows high fatigue. The app does not impose a fixed 4–6-week block.
Wernbom et al. 2007
Proportional Development
Muscle-group-specific volume ranges for balanced development.
Zourdos et al. 2023: MASS Research Review
Autoregulation via RIR
RIR-based weight adjustment in real time for optimal training management.
Pelland et al. 2024 (supplementary)
Fractional Set Counting
Secondary muscle loading in compounds: every set counts toward all the muscles involved, secondary muscles partially.
