Table 3.

Specifications of analyzed trials to evaluate type I and II muscle fibers

Study	Total sample size (Baseline)	Sex	Participants characteristics	Body mass index (kg/m2) (Baseline)	Frequency (days/week)	Intervention duration (weeks)	Exercise intervention	Results	PEDro score
Karlsen et al. (26)	24	Male	Healthy older adults	25.9 ± 3.6	3	13	Resistance training (RT) for both legs	Boosting SC availability in healthy elderly men does not enhance the subsequent muscle hypertrophy response to RT.	7
Moro et al. (27)	19	Female/Male	Healthy older adults	29.7 ± 3.1	3	12	progressive Resistance exercise training (RET) program	This study provides intriguing evidence for a fibre type-specific response to RET in older adults and suggests flexibility in the myonuclear domain of type II fibres during a hypertrophic stimulus.	8
Snijders et al. (28)	22	Male	Healthy older adults	27.4 ± 0.6	3	24	Progressive resistance type exercise training	Type II muscle fibre capillarization at baseline may be a critical factor for allowing muscle fibre hypertrophy to occur during prolonged resistance exercise training in older men.	6
Snijders et al. (29)	14	Male	Healthy older adults	28.0 ± 4.0	2	12	A resistance exercise session consisted of a 5 min warm-up on a cycle ergometer, followed by three sets of four separate exercises in the following order: leg press, chest press or lateral pull-down, horizontal row or shoulder press, and leg extension	The acute muscle satellite cell response following exercise can be improved by prolonged exercise training in older men.	7
Verdijk et al. (29)	13	Male	Healthy older adults	27.4 ± 1.1	3	12	Training consisted of 5 minutes of warming-up on a cycle ergometer, followed by four sets on both the leg press (LP) and leg extension (LE) machines, and a 5-minute cooling-down period on the cycle ergometer	No changes were observed in the Type I muscle fibers. In older adults, skeletal muscle tissue is still capable of inducing SC proliferation and differentiation, resulting in Type II muscle fiber hypertrophy.	5
Verdijk et al. (31)	53	Male	Healthy older adults	No data	3	12	Training consisted of a 5-minutes warm-up on a cycle ergometer, followed by four sets on both the leg press and leg-extension machines, followed by a 5- minutes cooling down period on the cycle ergometer	Twelve weeks of resistance-type exercise training significantly increased type II muscle fiber size and satellite cell content.	6
Verney et al. (32)	10	Male	Healthy older adults	27.5 ± 3.0	3	14	Resistance training bouts included three exercises with three sets per exercise that targeted muscles of the arms and trunk	This study provide a practical reference for the determination of optimal exercise protocols for improved muscle function and regeneration in elderly individuals.	6

Resistance Training and Muscle Stem Cells in Older Adult