Table 2.
Characteristics of the RCTs and non-RCTs included in the review.
| Author (Year) | Follow-Up | Intervention | Control | Outcomes | Main Results |
|---|---|---|---|---|---|
| Goldfield et al. (2018) RCT [4] |
6 months (4 days per week) |
(1) Aerobic (20–45 min, 65–85% HRmax) (2) Resistance (20–45 min, exercises with 2 × 15 progressing to 3 × 8, 8RM) (3) Combined (Complete aerobic training program plus resistance training program during each session) |
The control group received only dietary counselling with no exercise prescription | Serum BDNF (ng/mL) | No significant within- or between-group changes in BDNF Aerobic group (△ = +1.80) Resistance group (△ = −2.00) Combined group (△ = −1.70) |
| Jeon and Ha 2015) RCT [15] |
8 weeks (3 days per week) |
Exercise was performed on treadmills and the exercise intensity was set between 40% and 60%VO2R | The control group were asked to continue their daily normal and sedentary activities | Serum BDNF (pg/mL) |
The exercise group showed a significant increase in BDNF levels (p < 0.001) Exercise (△ = +4.25) Control (△ = +0.85) |
| Jeon and Ha (2017) RCT [16] |
12 weeks (4 days per week) |
(1) Low-intensity aerobic exercise (43.34 ± 3.59 min, 40% VO2R) (2) Moderate-intensity aerobic exercise (33.33 ± 3.64 min, 55% VO2R) (3) High-intensity aerobic exercise (25.76 ± 2.10 min, 70% VO2R) |
The SG performed whole-body stretching for 30 min at the same time, frequency and location as the aerobic exercise groups. | Serum BDNF (ng/mL) | The MIEG (p < 0.05) and HIEG (p < 0.01) groups showed a significant increase in BDNF levels LIEG (△ = +0.26) MIEG (△ = +1.81) HIEG (△ = +4.85) SG (△ = +0.54) |
| Kim et al. (2015) RCT [33] |
12 weeks (5 days per week) |
Combined exercise group (CEG): taekwondo movement-based exercise program (60 min, 50–80% HR) | No exercise | Serum BDNF (ng/mL) | The CEG showed improvements in BDNF levels, but there was no significant difference between the groups Combined group (△ = +2.58) Control group (△ = +0.07) |
| Lee et al. (2014) Non-RCT [34] |
12 weeks (3 days per week) |
(1) Obesity group: aerobic exercise (40–60 min, 40–60% VO2max) | No exercise | Serum BDNF (pg/mL) | Only GO showed a significant increase in BDNF levels (p < 0.05) Obesity group (△ = +11.62) Control group (△ = −0.51) |
| Shim and Kim (2012) Non-RCT [35] |
12 weeks (3 days per week) |
(1) Exercise group (20–25 min, 55–75% HRmax) and resistance (20–45 min, exercises with 3 × 8 progressing to 3 × 15, 50–70% 1RM) | No exercise | Serum BDNF (ng/mL) | The EG showed improvements in BDNF levels, but there was no significant difference between the groups Exercise group (△ = +2.58) Control group (△ = +0.07) |
BDNF= Brain-Derived Neurotrophic Factor; HR = heart rate; HRmax = maximum heart rate; VO2max = maximum oxygen consumption; VO2R = reserve oxygen consumption; RM = maximum resistance; LIEG = Low-intensity aerobic exercise group; MIEG = moderate-intensity aerobic exercise group; HIEG = high-intensity aerobic exercise group; SG = Stretching group.