TRAINING PRINCIPLES

Progressive overload

Keep lifting the same weight for the same reps and the only message your body gets is that it has already adapted.

The short answer

Tailrep's programs use double progression: climb to the top of the rep range, then add weight.

In Plotkin et al.'s (2022) eight-week trial, progressing load and progressing reps produced almost the same hypertrophy and strength outcomes.
So adding weight every session isn't mandatory. Progressing through reps is a legitimate route.
Huang et al.'s (2025) network meta-analysis found autoregulated loading — adjusting to how the day is going — more effective for maximal strength than fixed percentages of 1RM.

Once every set reaches the top of the rep range, add weight and restart from the bottom
Roughly 2.5 kg upper body, 5 kg lower body. If your equipment can't make that jump, progress reps first
Two weeks with no movement means the problem is probably volume, rest, or sleep — not the weight
Start a session without checking last time's numbers and you can't tell whether anything improved. That's why Tailrep pulls your previous sets from history and routines

Limits of this evidence, The trials comparing progression methods run about eight weeks. Which one wins over years isn't known.

Plotkin D, et al. (2022) PeerJ
Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations
Individual trialDOI: 10.7717/peerj.14142 View on PubMed
Huang Z, et al. (2025) Journal of Exercise Science and Fitness
Autoregulated resistance training for maximal strength enhancement: A systematic review and network meta-analysis
Systematic review / meta-analysisDOI: 10.1016/j.jesf.2025.07.006 View on PubMed