Table 1.

Summary of studies evaluating the effect of exercise training on BDNF levels and related metabolic indicators in patients with type 2 diabetes (human studies)

Author-Date/PEDro Quality	Participants	Experimental Group(Independent Variable)	Control Group	Dependent Variable	Results
Baker et al. (2010)/5 [60]	28 men (57–83 years old) suffering from glucose intolerance Groups: Training and Control.	Aerobic training (elliptical machine, ergometer cycle or treadmill) during 6 months, 4 sessions per week, each session 45–60 min, with intensity 75% -85% of heart rate reserve.	balance and stretching training, 6 months, 4 sessions per week, each session 45–60 min, with intensity ≤50% of the heart rate reserve.	BDNF Glucose Insulin	Insignificant changes in all variables
Lee et al. (2014)/5 [45]	26 adolescents (13–19 years old); 17 boys and 9 girls; healthy, obese, and with type 2 diabetes. Groups: Diabetes-Training, Obese-Training, and Healthy inactive.	Diabetic and obese groups. Aerobic training (walking and running), 12 weeks, 3 sessions per week, with 50% - 60% VO2max, each session 40–60 min.	Age matching of participants of the control group based on other groups	BDNF	Significant increase of BDNF in the obese group
Swift et al. (2012)/5 [62]	150 men and women (30–75 years old), 86 women and 64 men, suffering from type 2 diabetes Groups: aerobic training, resistance training, concurrent training, and without training.	Aerobic training: 50%–80% VO2max. Resistance training: 3 sessions per week, each session consisting of 2 sets of 4 exercises for the upper trunk, 3 sets of 3 exercises for the lower trunk, and 2 sets of 2 exercises for core (each set with 10–12 repetitions). Concurrent training: 2 sessions per week, each session consisting of 1 set of 9 exercises.	Recommended weekly stretching and relaxation exercises and maintaining daily activity for 9 months	BDNF	Insignificant changes in serum BDNF levels after aerobic, resistance and concurrent training compared to the control group.
Stomby et al. (2017)/5 [61]	30 participants (men: 30–75 years old, and women: up to 75 years old), obese and overweight with type 2 diabetes. Groups: Paleolithic diet, Paleolithic diet-training, and training.	12 weeks, 3 sessions per week, each session 60 min of resistance and aerobic training.	Consumption of pure meat, fish, eggs, fruits, berries, vegetables and nuts.	BDNF Glucose Insulin	BDNF elevation in both diet and training-diet groups. Significant reduction in glucose and insulin in both diet and training-diet groups.