Table 1. Characteristics of the included studies.

Study	Participants	Characteristics	Stretching method	Muscles stretched	Amplitude/intensity	Volume (sets, duration/repititions)	Velocity/frequency	Flexibility outcome
Barbosa et al. (2018)	Healthy, physically active males	Total: n = 45, DS: n = 15 (21.47 ± 3.0 years), CG: n = 15 (21.27 ± 2.8 years)	DS	Hamstrings	Mild discomfort	30 reps × 3 sets	Established “beep” rate	Knee extension ROM
Behm et al. (2011)	Young and middle-aged males	Total: n = 18, Young: n = 10 (22 ± 1.4 years), Middle-aged: n = 8 (46.3 ± 6.5 years)	DS	Quadriceps, Hamstrings, Plantar flexors	The highest ROM possible for all DS	8 reps (30 s) × 3 stretches	Not reported	Hip extension ROM, Sit-and-reach test
Chen et al. (2018)	Healthy young males	Total: n = 36 (22.0 ± 1.5 years), DS (CKC): n = 12, DS (OKC): n = 12, CG: n = 12	DS (CKC), DS (OKC)	Hamstrings	ROM (less than the point of discomfort)	DS (CKC): 8 reps (15 s) × 6 sets, DS (OKC): 15 s × 6 sets	DS (CKC): 1:1 s, DS (OKC): Not reported	Straight-leg raise test
Hernández-Trujillo et al. (2024)	Healthy, recreationally active males and females	Total: n = 60 (46.4 ± 5.5 years, 30 males and 30 females), BS: n = 20 (10 males and 10 females), CG: n = 20 (10 males and 10 females)	BS	Quadriceps, Hamstrings, Hip extensors, Hip flexors, Hip adductors, Hip abductors	ROM	20 s × 3 sets × 6 stretches	Following the metronome rhythm (40 bpm)	Hip flexion ROM, Knee flexion ROM
Inoue and Nagano (2023)	Healthy adult males	Total: n = 12 (21.2 ± 0.6 years)	DS, BS	Hamstrings	70%–90% of the maximum value of the POD	2 min × 4 sets	Not reported	Straight-leg raise test
Jung et al. (2023)	Healthy young males and females	Total: n = 44 (36 males and 8 females) DS: n = 11 (26.27 ± 1.68 years, 9 males and 2 females), BS: n = 11 (26.73 ± 2.15 years, 9 males and 2 females), CG: n = 11 (27.45 ± 3.17 years, 9 males and 2 females)	DS, BS	Plantar flexors	DS: Not reported, BS: 2–5° at the end ROM	45 s × 4 sets	DS: Once per second, BS: Twice per second	Ankle DF ROM
Kaneda et al. (2020)	Healthy young males	Total: n = 17 (23.2 ± 1.1 years)	DS	Hamstrings	ROM	15 reps (30 s) × 4 sets	Once every 2 s	Straight-leg raise test, Passive knee extension test
Konrad et al. (2017)	Healthy young males and females	Total: n = 122 (79 males and 43 females), BS: n = 24 (22.6 ± 2.8 years, 16 males and 8 females), CG: n = 24 (23.8 ± 3.5 years, 11 males and 13 females)	BS	Planter flexors	The last 5° of the individuals’ ROM	30 s × 4 sets	At a frequency of 1 Hz	Ankle DF ROM
Mizuno (2017)	Healthy young males and females	Total: n = 15 (8 males and 7 females, 23 ± 2 years)	DS (1 set), DS (4 sets), DS (7 sets)	Plantar flexors	ROM	15 reps (30 s) × 1 set, 15 reps (30 s) × 4 sets, 15 reps (30 s) × 7 sets	Once every 2 s	Ankle DF ROM
Mizuno and Uemura (2016)	Healthy young males and females	Total: n = 12 (8 males and 4 females, 23 ± 1 years)	DS	Plantar flexors	ROM	15 reps (30 s) × 4 sets	Once every 2 s	Ankle DF ROM
Muanjai and Namsawang (2023)	Healthy young and older adult females	Total: n = 30, Young: n = 15 (20.9 ± 0.7 years), Older: n = 15 (66.6 ± 4.2 years)	DS	Hamstrings	The point of maximum discomfort without pain	8 reps × 6 sets	Stretch the hamstring muscles for 1 s and 1 s down back to the starting position	Straight-leg raise test, Sit-and-reach test
Murphy et al. (2010)	Healthy, physically active males	Total: n = 42, DS: n = 13 (20 ± 2 years), CG: n = 15 (21 ± 2 years)	DS	Pectoralis major, Deltoids, Latissimus dorsi, Hamstrings, Quadriceps, Gluteus maximus, Hip flexors, Calves	Until subjects felt slight discomfort, but not to a range of motion that produced pain	10 reps (20 s) × 12 stretches	Once every 2 s	Hip flexion ROM, Knee flexion ROM, Sit-and-reach test
Nelson and Kokkonen (2001)	College students	Total: n = 22 (males: 23.3 ± 2.7 years, females: 21.6 ± 3.0 years, 11 males and 11 females)	BS	Quadriceps, Hamstrings, Gluteals, Hip Adductors, Plantar flexors	2–5° at the end of the ROM	15 s × 3 sets unassisted × 5 stretches, 15 s × 3 sets assisted × 5 stretches	Once per second	Sit-and-reach test
Oliveira et al. (2018)	Trained young male soccer players	Total: n = 12 (17.67 ± 0.87 years)	BS	Quadriceps, Hamstrings, Hip extensors, Planter flexors	The maximum POD	30 s × 3 sets × 4 stretches	1:1 s	Sit-and-reach test
Paradisis et al. (2014)	Active adolescent boys and girls	Total: n = 47 (14.6 ± 1.7 years, 17 males and 30 females)	DS	Quadriceps, Hamstrings, Hip extensors, Plantar flexors	Not reported	20 reps (40 s) × 4 stretches	Once every 2 s	Sit-and-reach test
Ryan et al. (2014)	Healthy males	Total: n = 26 (22.2 ± 1.3 years)	DS, DS (twice the volume)	Quadriceps, Hamstrings, Hip extensors, Hip flexors, Hip adductors, Hip abductors, Plantar flexors	ROM	DS: 4 reps × 8 stretches, 6 reps × 3 stretches, DS (twice the volume): 8 reps × 8 stretches, 12 reps × 3 stretches	In a controlled manner through a ROM	Sit-and-reach test
Wiemann and Hahn (1997)	Healthy males	Total: n = 69 (aged 20 to 34), BS: n = 16, CG: n =15	BS	Hamstrings	Not reported	15 s × 3 sets × 3 stretches	Rhythmically	Hip flexion ROM

DS: dynamic stretching, BS: ballistic stretching, CKC: closed kinetic chain, OKC: open kinetic chain, CG: control group, ROM: range of motion, POD: point of discomfort, DF: dorsiflexion. Values are expressed as the mean ± standard deviation.