This Week in Training Science

Key takeaway: The week's research reinforces that you don't need to train to momentary failure for strength or hypertrophy — high, well-calibrated effort with a few reps in reserve is sufficient — and that muscle size gains explain only part of your strength progress.

Week 35 brought two research-backed challenges to widely held assumptions — one about training to failure, another about the muscle size–strength relationship. Alongside those, practical content covered peaking blocks, myoreps, PHUL and StrongLifts app comparisons, and a grounded look at thumb hole gym shirts.

Research Highlights

Training to failure isn't required — but effort calibration is. The established literature on proximity to failure converges on a consistent conclusion: stopping short of momentary failure produces comparable strength and hypertrophy adaptations, provided effort is genuinely high. A 2023 meta-analysis by Refalo and colleagues in the Journal of Sports Sciences found that training closer to failure offered no meaningful hypertrophy advantage once effort was sufficiently high, and that stopping short reduced fatigue cost.

A related and often underappreciated point is that accurately gauging proximity to failure — your RPE or RIR accuracy — appears to be a trainable skill rather than a fixed trait. Work on RPE/RIR-based load prescription (e.g., Zourdos and colleagues' research on the repetitions-in-reserve–based RPE scale, and Halperin's work on subjective effort) supports the idea that lifters who deliberately practice estimating reps left in the tank improve the accuracy of their self-regulation over time, which can help them apply appropriate effort more consistently.

Muscle size explains less of your strength than you might think. A well-established body of research indicates that changes in muscle cross-sectional area account for only a modest portion of the variance in strength gains. Work from Loenneke, Buckner and colleagues has repeatedly questioned the strength of the hypertrophy–strength link, and studies such as Balshaw et al. show that CSA explains only part of the between-individual variance in strength. Neural adaptations, muscle architecture, and measurement methodology all complicate the picture. The practical implication: don't treat hypertrophy as a reliable proxy for strength progress, and don't be discouraged when the two diverge.

Expert Insights

The broader research base reinforces that the stimulus for adaptation is proximity to failure, not failure itself. This supports a training approach centered on consistent, honest effort rather than grinding every set to the floor.

Industry Updates

App comparisons for structured programs. Two guides this week evaluated the leading tracking apps for PHUL and StrongLifts 5x5. The consistent finding: apps that automate progressive overload and handle alternating session structures outperform basic loggers for these programs. The official StrongLifts app remains a capable default for 5x5, but it has meaningful competition in 2026.

Training Takeaways

  • Stop chasing failure by default. High effort with 1–3 reps in reserve is sufficient for adaptation — and likely more sustainable across a training block.
  • Treat RPE accuracy as a skill to practice. Regularly estimating reps left in the tank, then testing it, sharpens your self-regulation over time.
  • Don't conflate muscle growth with strength progress. The two are related but not interchangeable — track both independently and interpret each on its own terms.
  • Peaking is about fatigue management, not just intensity. Arriving at competition day with maximum fitness requires deliberate volume reduction in the final weeks — fitness is built before the block, expressed during it.
  • Myoreps are a time-efficient tool, not a shortcut. They work by accumulating effective reps near failure across short clusters — the mechanism is sound, but execution precision matters.