Have pre-exhaustion, mind-muscle connection, and lengthened partials been debunked?
In July 2025, Director of Bayesian Bodybuilding Menno Henselmans reviewed three recent studies challenging popular beliefs about hypertrophy training. The takeaways suggest that more nuance is involved with certain training techniques. The three biggest were:
Takeaways
1. The Pre-Exhaustion Problem
The first study Henselmans examined, still in preprint, looked at two-leg day setups. (1) One group followed a traditional sequence of leg curls, Romanian deadlifts (RDL), leg extensions, and squats, with two-minute rest intervals.
The second group, “pre-exhausted,” performed isolation exercises before the compound exercises (e.g., leg curls before RDLs, leg extensions before squats) with minimal rest between them.
After eight weeks, the traditional group showed greater overall quad and hamstring muscle growth. Strength gains were also marginally better. Despite small and statistically non-significant differences, Henselmans argued that the results would hold up with improved studies.
Post-failure training has a poor stimulus-to-fatigue ratio.
—Menno Henselmans
Increasing training loads positively influence physique progress. Pre-exhaustion sets fatigued muscles, which reduces mechanical tension and high-threshold motor unit recruitment. (2) Henselmans’ collaborative work aimed to debunk short rest intervals as more anabolic than longer ones. (3)(4)
2. The Myth of Mind-Muscle Connection
The second study investigated whether consciously focusing on the pecs during bench presses increases pec activation. Participants performed bench presses in a Smith machine with no mental cue or while focusing on their pecs. (5)

The trained lifters could not increase pectoralis major muscle activity by focusing on it. Henselmans explained that the motor cortex is already highly optimized for task execution.
“When doing a good chest exercise, your chest will be maximally activated if you focus on maximum performance,” Henselmans explained. Try deadlifting your one-rep max with your quads. It won’t happen, and you’ll decrease force output.
Hence, biomechanics and proper exercise selection should take priority over internal cueing. A mind-muscle connection may be more useful during isolation techniques than compound lifts.
3. Lengthened Partials Hype
Lastly, a 2025 study re-analyzed data from a popular earlier paper by Pedrosa et al., which claimed that leg extensions performed in the stretched position (lengthened partials) induced greater hypertrophy than full range of motion (ROM) training. (6)
Untrained women performed various protocols: full ROM, lengthened partials, shortened partials, and a combo of the two.
“Lengthened partials didn’t significantly outperform full range of motion training at the whole muscle level,” Henselmans noted. Only short partials underperformed. The hype surrounding lengthened partials, Henselmans argued, may have stemmed from inflated early findings.
“We often see this in research where a first study reports a significant result… and the effect size turns out to be much smaller than initially believed,” Henselmans said. He didn’t dismiss lengthened partials entirely, though, as they could still enhance stimulus during leg extensions or calf raises, which lack tension at long muscle lengths. (7)
“High tension at long lengths is important, [but] not so important to only have high tension at long lengths,” Henselmans concluded.
More Training Content
References
- Author(s). (2025, June). SportRxiv. Preprint. Retrieved from https://sportrxiv.org/index.php/server/preprint/view/564
- Krzysztofik M, Wilk M, Wojdała G, Gołaś A. Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. Int J Environ Res Public Health. 2019 Dec 4;16(24):4897. doi: 10.3390/ijerph16244897. PMID: 31817252; PMCID: PMC6950543.
- Henselmans M, Schoenfeld BJ. The effect of inter-set rest intervals on resistance exercise-induced muscle hypertrophy. Sports Med. 2014 Dec;44(12):1635-43. doi: 10.1007/s40279-014-0228-0. PMID: 25047853.
- Schoenfeld BJ, Pope ZK, Benik FM, Hester GM, Sellers J, Nooner JL, Schnaiter JA, Bond-Williams KE, Carter AS, Ross CL, Just BL, Henselmans M, Krieger JW. Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men. J Strength Cond Res. 2016 Jul;30(7):1805-12. doi: 10.1519/JSC.0000000000001272. PMID: 26605807.
- Nascimento PHF, Caldeira CN, Diniz RCR, Andrade AGP, Chagas MH, Lima FV. Internal Focus of Attention did Not Change Muscle Activation and the Rate of Perceived Exertion in Bench Press Exercise in Successive Training Sessions. Percept Mot Skills. 2025 May 15:315125251343156. doi: 10.1177/00315125251343156. Epub ahead of print. PMID: 40372111.
- Pedrosa GF, Simões MG, Rezende Pereira M, Schoenfeld B, Lanza MB, Lima FV, Bischoff ABG, Chagas MH, Diniz RCR. From full to partials: Investigating the impact of range of motion training on maximum isometric action, and muscle hypertrophy in young women. J Sports Sci. 2025 Aug;43(15):1440-1451. doi: 10.1080/02640414.2025.2502895. Epub 2025 May 14. PMID: 40366729.
- Pedrosa GF, Lima FV, Schoenfeld BJ, Lacerda LT, Simões MG, Pereira MR, Diniz RCR, Chagas MH. Partial range of motion training elicits favorable improvements in muscular adaptations when carried out at long muscle lengths. Eur J Sport Sci. 2022 Aug;22(8):1250-1260. doi: 10.1080/17461391.2021.1927199. Epub 2021 May 23. PMID: 33977835.
Featured image via Shutterstock/PeopleImages.com – Yuri A