Long-term time-course of strength adaptation to minimal dose resistance training: Retrospective longitudinal growth modelling of a large cohort through training records

Abstract

Objective: Public health guidelines for resistance training typically emphasize a minimal effective dose approach. The intention for such guidelines is that individuals engage in these behaviors over the long-term. However, relatively few studies have examined the longitudinal time-course of strength adaptations to resistance training and those which have typically utilize small samples and/or athletic populations. Further, no studies have employed approaches to incorporate participant level random factors into modelling. Thus, the aim of this study was to examine the time-course of strength development resulting from continued participation in minimal dose resistance training in a large sample through retrospective training records. Methods: Data was available for analysis from 14,690 participants who had undergone minimal dose resistance training (1x/week, single sets to momentary failure of six exercises) with records ranging up to 352 weeks (~6.8 years) in length. Linear-log growth models examining the development of strength over time were fit allowing random intercepts and slopes by participant. In addition, the interaction of sex and age were examined as fixed effects. Results: All models demonstrated a robust linear-log relationship which on the untransformed time scale clearly demonstrated the presence of a plateau in strength development around ~1 year into training after which strength was essentially maintained with minimal growth. Sex and age had minimal interaction effects. Conclusions: Substantial strength gains are possible with the use of a minimal dose resistance training approach. Though, these begin to plateau after ~1 year of training with little impact from sex or age on the emergence of this plateau. It is unclear if this plateau can be overcome through alternative approaches. Considering this, our results support public health recommendations for minimal dose resistance training to induce and maintain strength adaptations in adults.

The Minimum Effective Training Dose Required for 1RM Strength in Powerlifters

“…These PL total increases are much lower than what was expressed by the participants of the survey, who expressed that a 17.5 ± 12.1 kg increase in PL total would be regarded as meaningful. Indeed, strength gains in PL athletes when exploring the open powerlifting dataset (https://www.openpowerlifting.org/) suggest that strength gains are relatively small and follow a linearlog relationship with time (Steele et al, 2021; see https://osf. io/preprints/sportrxiv/eq485/).…”

“…These PL total increases are much lower than what was expressed by the participants of the survey, who expressed that a 17.5 ± 12.1 kg increase in PL total would be regarded as meaningful. Indeed, strength gains in PL athletes when exploring the open powerlifting dataset ( https://www.openpowerlifting.org/ ) suggest that strength gains are relatively small and follow a linear-log relationship with time (Steele et al, 2021 ; see https://osf.io/preprints/sportrxiv/eq485/ ). Considering that strength gains become relatively smaller with training/competition age to the point of almost plateauing, this may help explain the responses of some of the PL athletes and coaches who expressed that any strength change in 6 weeks can be considered as meaningful, especially at the elite level.…”

“…Based on the currently available evidence, the METD for powerlifters may be slightly higher than the METD for recreationally trained individuals. A recent study by Steele et al ( 2021 ) analyzed the training data of 14,690 participants who had been training 1 time per week performing single sets to momentary failure on six exercises and found that the participants were able to make substantial strength increases for ~1 year. Further, several studies in untrained or recreationally trained participants have single 1RM lifts compared to more traditional resistance training produce similar improvements in 1RM strength (Dankel et al, 2017 , 2020 ; Mattocks et al, 2017 ; Buckner et al, 2021 ).…”

Bodyweight Training for Muscular Strength & Endurance

“…a) Choice of exercise: select bodyweight exercises that utilize the major muscle groups. According to the minimal dose approach for resistance training [31][32][33], As little as 2-exercises per major muscle group can improve strength and functional ability in younger and older adults [31]. Therefore, the choice of exercises should be based on training status, goals and time constraints.…”

Long-Term Adaptations in the Squat, Bench Press, and Deadlift: Assessing Strength Gain in Powerlifting Athletes

“…T he importance of muscular strength for overall health (1,2) and human performance (3) is well documented. Indeed, strength adaptations to resistance training have predominantly been investigated in short-to-medium term studies, with less evidence examining the long term (i.e., >1 yr or longer) effects (see (4)(5)(6), for general population example, see (7)) because of, for example, logistical and resource limitations. However, strength athletes already training and competing in respective sports (e.g., powerlifting [PL] and weightlifting) can provide a feasible and an ecologically valid model to assess longer-term adaptations to resistance training aimed at improving maximum strength or power (8)(9)(10)(11)(12).…”