Table 1

Study inclusion and exclusion criteria

Inclusion criteriaExclusion criteria
  • Humans ≥18 years old.

  • Generally healthy (no disease condition indicated other than sarcopenia).

  • Community-dwelling adults.

  • Upper-body, lower-body and/or whole-body resistance training.

  • RTx aligns with one predefined node; specifically, exercises performed:

  • with high(H; ≥80% 1 RM or ≥8 RM) or low(L; <80% 1 RM or >8 RM) load, AND

  • for a single (S) or multiple (M) sets, AND

  • once-weekly (1), twice-weekly (2) or at least thrice-weekly (3).

  • Intervention duration ≥6 weeks.

  • RTx variable (load, sets or frequency) differentially prescribed between training groups

  • Eligible RTx compared with CTRL.

  • Eligible outcome(s) assessed pre-intervention and post-intervention.

Muscle strength:
  • 1RM test.

  • Isometric maximum voluntary contraction.

  • Isokinetic maximum voluntary contraction.

Muscle size: Fat-free mass, fat-free and bone-free mass, lean mass, whole-muscle cross-sectional area or volume or thickness or muscle fibre cross-sectional area. Eligible measurement instruments:
  • Ultrasonography.

  • MRI.

  • CT.

  • Bioelectrical impedance.

  • Dual-energy X-ray absorptiometry.

  • Hydrostatic weighing.

  • Air displacement plethysmography.

  • Microscopy.

Physical function: Assessed physical function in older adults (mean age ≥55 years old) in the domain(s):
  • Mobility: (defined as a person’s ability to move physically, eg, Timed Up and Go Test, Chair Rise Sit to Stand).

  • Balance: (defined as the ability to maintain a controlled body position during a given task, eg, Berg Balance Test, Sit and Reach Test).

  • Gait speed: (defined as the time it takes to cover a given distance, eg, 6 Minute Walk Test, or 25 Foot Walk Test).

Study design
  • Randomised trial.

  • Reported in English.

  • Non-human species.

  • <18 years old.

  • Persons with or at risk for comorbidities (eg, cardiovascular disease, type II diabetes, type I diabetes, cancer, peripheral artery disease, osteoarthritis).

  • Persons that are injured (eg, musculoskeletal-related fracture and/or repair).

  • Athletes or military personnel.

  • Explicitly mentions obese and/or overweight participants.

  • Individuals that are hospitalised (inpatient/outpatient/rehabilitation).

  • Individuals living in long-term care homes.

  • Resistance training involved added intervention (eg, blood flow restriction)

  • RTx does not align with one node (eg, load 60–90% 1RM).

  • Explicitly mentions unsupervised resistance training.

  • Resistance training familiarisation/lead-in >4 weeks.

  • CTRL received treatment beyond habitual lifestyle (eg, nutritional advice, lifestyle consultation).

  • Eligible RTx not compared with another eligible RTx nor CTRL.

  • No measure of muscle strength, size, mobility, gait speed or balance.

Study design
  • Non-randomised trials.

  • Systematic reviews (ie, systematic reviews; meta-analyses review; meta-regressions; umbrella reviews; network meta-analyses).

  • Narrative reviews.

  • Observational studies (eg, retrospective, prospective or longitudinal).

  • CTRL, non-exercise control; 1RM, one-repetition maximum; RTx, resistance training prescription.