Are Trainees Lifting Heavy Enough? Self-Selected Loads in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis

Individualized pleasure-oriented exercise sessions, exercise frequency, and affective outcomes: a pragmatic randomized controlled trial

BACKGROUND

Affective responses are increasingly recognized as potentially effective intervention targets that may facilitate exercise and physical activity behavior change. While emerging correlational evidence suggests that more pleasant affective responses are associated with higher participation and adherence, experimental evidence remains scarce. In light of this, we conducted a preregistered, pragmatic, single-blinded, superiority randomized controlled trial with two parallel groups, with the goal of determining the impact of an individualized exercise-intensity prescription targeting pleasure on exercise frequency.

METHODS

Forty-seven non-regular exercisers were randomized into two groups. For both groups, the intervention consisted of three exercise sessions based on the Frequency-Intensity-Time-Type (FITT) principle. However, the experimental group also received an individualized intensity prescription based on prior assessment of preference for and tolerance of exercise intensity, as well as instructions emphasizing the promotion of pleasure as a basis for self-regulating exercise intensity. The primary outcome was gymnasium attendance over an eight-week follow-up period. Secondary outcomes were affective valence and arousal, post-exercise enjoyment, core affective exercise experiences, and anticipated and remembered affect.

RESULTS

Forty-six participants were retained for analysis (Mage = 32.00; SD = 8.62 years; 56.5% female). Compared to the control group, the experimental group exhibited 77% higher session attendance (14.35 vs. 8.13 sessions) over the eight-week follow-up period (group main effect p = .018, η2p = .120; Cohen's d ranged from 0.28 to 0.91 during follow-up). Also, the experimental group reported higher levels of pleasure during the intervention sessions (for all group main effects, p < .001, η2p from .33 to .37) and higher levels of remembered pleasure (group main effect p = .021, η2p = .116) and anticipated pleasure (group main effect p = .022, η2p = .114). No harm was detected.

CONCLUSIONS

These results demonstrate the practicality and effectiveness of an intervention aimed at enhancing affective responses to exercise in improving short-term session attendance.

TRIAL REGISTRATION

ClinicalTrial.gov NCT05416593.

Assessing the efficacy of the Stop OsteoARthritis (SOAR) program: A randomized delayed-controlled trial in persons at increased risk of early onset post-traumatic knee osteoarthritis

OBJECTIVE

Assess the efficacy of an 8-week virtual, physiotherapist (PT)-guided knee health program (Stop OsteoARthritis (SOAR)) to improve knee extensor strength in individuals at risk of post-traumatic knee osteoarthritis (PTOA).

METHOD

In this superiority, randomized delayed-control trial, persons aged 16-35 years, 1-4 years after a self-reported knee joint injury were randomly assigned (1:1) to receive the SOAR program immediately (experimental group) or after a 9-week delay (control group). SOAR includes 1) one-time Knee Camp (virtual PT-guided group education, knee assessment, 1:1 exercise and physical activity (PA) goal-setting); 2) Weekly personalized home-based exercise and PA program with tracking; 3) Weekly 1:1 PT counseling (virtual). The primary outcome was a change in isokinetic knee extensor strength (baseline to 9-weeks). Additional outcomes included change in self-reported knee-related quality-of-life (QOL), self-efficacy, self-management and kinesiophobia, and PA (accelerometer) at 9 and 18-weeks. Linear regression models estimated the effect of the 8-week intervention at the primary endpoint (9-week).

RESULTS

49 of 54 randomized participants completed the study (91%). Participants were a mean ± standard deviation age of 27 ± 5.0 years, and 2.4 ± 0.9 years post-injury. No mean between group differences for the primary (0.05; 95% confidence interval (CI): -0.10, 0.19) or other outcomes were seen at 9 weeks except for greater improvements in perceived self-management (Partner in Health Scale; 11.3/96, 95%CI: 5.5, 17.1) and kinesiophobia (Tampa Scale of Kinesiophobia; -4.4/33, 95%CI: -7.0, -1.8).

CONCLUSION

For active persons with elevated risk of PTOA, an 8-week SOAR program did not change knee-related strength, QOL, self-efficacy, or PA, on average, but may benefit the ability to self-manage knee health and kinesiophobia.

Resistance Exercise Minimal Dose Strategies for Increasing Muscle Strength in the General Population: an Overview

Many individuals do not participate in resistance exercise, with perceived lack of time being a key barrier. Minimal dose strategies, which generally reduce weekly exercise volumes to less than recommended guidelines, might improve muscle strength with minimal time investment. However, minimal dose strategies and their effects on muscle strength are still unclear. Here our aims are to define and characterize minimal dose resistance exercise strategies and summarize their effects on muscle strength in individuals who are not currently engaged in resistance exercise. The minimal dose strategies overviewed were: "Weekend Warrior," single-set resistance exercise, resistance exercise "snacking," practicing the strength test, and eccentric minimal doses. "Weekend Warrior," which minimizes training frequency, is resistance exercise performed in one weekly session. Single-set resistance exercise, which minimizes set number and session duration, is one set of multiple exercises performed multiple times per week. "Snacks," which minimize exercise number and session duration, are brief bouts (few minutes) of resistance exercise performed once or more daily. Practicing the strength test, which minimizes repetition number and session duration, is one maximal repetition performed in one or more sets, multiple days per week. Eccentric minimal doses, which eliminate or minimize concentric phase muscle actions, are low weekly volumes of submaximal or maximal eccentric-only repetitions. All approaches increase muscle strength, and some approaches improve other outcomes of health and fitness. "Weekend Warrior" and single-set resistance exercise are the approaches most strongly supported by current research, while snacking and eccentric minimal doses are emerging concepts with promising results. Public health programs can promote small volumes of resistance exercise as being better for muscle strength than no resistance exercise at all.

Exercise instructors are not consistently implementing the strength component of the UK chief medical officers' physical activity guidelines in their exercise prescription for older adults

Strength training recommendations have been embedded within the UK's Chief Medical Officers' physical activity guidelines since 2011. There is limited evidence that these recommendations are used by exercise instructors in the community to underpin strength training prescription in the older adult population. This study aimed to explore exercise instructors' awareness and utilisation of the guidelines when prescribing strength training to older adults. Fifteen exercise instructors working with older adults in the UK participated in one online interview. A general inductive approach was conducted and thematic analysis allowed for major themes to be identified from the raw data. We found that most exercise instructors (n = 9), but not all (n = 6), were aware of the guidelines. Only one instructor (n = 1) had reportedly implemented the guidelines into their practice; other instructors reported that the guidelines were irrelevant. Instead, each of the instructors had their preferred sources of information that they relied on to underpin their exercise prescription, and each had their own interpretation of 'evidence-based strength training.' This individualised interpretation resulted in exceptionally varied prescription in the community and does not necessarily align with the progressive, evidence-based prescription known to build muscular strength. We suggest that (i) more detail on how to build muscular strength be embedded within the guidelines, (ii) a handbook on how to implement the guidelines be made available, (iii) theoretical and practical teaching materials and courses be updated, and/or (iv) a re-(education) of exercise instructors already in the field may be necessary to bring about a consistent, evidence-based strength prescription necessary for the best possible health and longevity outcomes for our ageing population.

Comparison of traditional vs. lighter load strength training on fat-free mass, strength, power and affective responses in middle and older-aged adults: A pilot randomized trial

OBJECTIVES

Strength training is widely recommended to improve strength, muscle mass and power. However, the feasibility and potential efficacy of strength training using lighter loads near failure on these outcomes in middle and older-aged adults remains unclear.

METHODS

23 community-living adults were randomized into two groups: Traditional strength training (ST) (8-12 repetitions) or a lighter load, higher repetitions (LLHR) (20-24 repetitions) group. Participants performed a full-body workout (twice a week) with 8 exercises at a perceived exertion of 7-8 (0-10 scale) for 10 weeks. Post-testing was performed by an assessor blinded to group assignments. An analysis of covariance (ANCOVA) was used to examine between group differences using baseline values as a covariate.

RESULTS

The study involved individuals with a mean age of 59 years, of which 61 % were women. The LLHR group demonstrated a high attendance rate of 92 % (9.5 %) and reported leg press exercise RPE of 7.1 (0.53), along with a session feeling scale of 2.0 (1.7). There was a trivial difference in fat free mass (FFM) favoring LLHR vs ST [0.27 kg 95 % CI (-0.87, 1.42)]. The ST group exhibited superior increases in leg press 1 repetition maximum (1RM) strength [-14 kg (-23, -5)], while the LLHR group showed greater strength endurance increases (65 % 1RM) [8 repetitions (2, 14)]. Leg press power [41 W (-42, 124)] and exercise efficacy [-3.8 (-21.2, 13.5)] demonstrated trivial between-group differences.

CONCLUSION

A pragmatic, full-body strength training program with lighter loads taken close to failure appears to be a viable option for promoting muscular adaptations in middle- and older-aged adults. These results are exploratory and require a larger trial for confirmation.

'A Lot of People Just Go for Walks, and Don't Do Anything Else': Older Adults in the UK Are Not Aware of the Strength Component Embedded in the Chief Medical Officers' Physical Activity Guidelines-A Qualitative Study

Strength recommendations have been embedded within the UK's Chief Medical Officers' physical activity guidelines since 2011. In 2019, they were given a more prominent position in the accompanying infographic. However, there is limited evidence that these recommendations have been successful in their population-wide dissemination. This study aimed to explore the engagement of community-dwelling older adults with the guidelines to date and to gain a nuanced understanding of the awareness, knowledge, and action that older adults take to fulfil strength recommendations. A total of fifteen older adults living in the UK participated in one online interview. A general inductive approach was used to generate themes from the data. There were four major themes that were found. 1. The strength component of the physical activity guidelines, 2. Barriers, 3. Motivators, and 4. Solutions. No participants were aware of the strength guidelines. When they were asked what activities they used to fulfil the 'build strength on at least two-days-per-week' criteria, walking, yoga, and Pilates were the most common responses. Ageism and strength training misconceptions were major barriers to participation in strengthening exercise. Older adults were much less aware of the benefits of building strength and strength training participation when compared to aerobic activities, so motivators to participation were generally not specific to strength training. Finally, there are several ways that practitioners can overcome the barriers to strength training participation. Solutions to improving the uptake and adherence to strength training participation are likely to be more successful when they include opportunities for social interaction, ability-appropriate challenge, and provide both short- and long-term benefits.