Table 4.
Summary of articles in trophic factors in older adults
| First author, year | Research design | n | Sex (% female) | Age, mean (S.D.) | Exercise mode | Exercise dose | Exercise min/week | Control/comparison group | Trophic factors outcomes | Main findings |
|---|---|---|---|---|---|---|---|---|---|---|
| Ruiz, 2015 | RCT | 40 | 80 | 92.3 (2.3) | Aerobic, cycle erg + resistance | 8 weeks, 3×/week, 40-45 min, 2-3 sets of 8-10 reps, RPE of 10-12, 30% of 1RM at start to 70% of 1RM | 120-135 min/week | Usual care | Serum levels of BDNF | No effect on BDNF serum levels |
| Kim, 2015 | RCT | 13 | 100 | 81 (2.6) | Exercise + MFGM supplementation, resistance, balance and gait training | 12 weeks, 2×/week, 60 min, RPE Borg 12-14 | 120 min/week | Exercise + placebo; MFGM supplementation; or only placebo group | BDNF and IGF-1 serum levels | No change in BDNF or IGF-1 |
| Levinger, 2008 | RCT | 49 | 49 | 50.9 (6.2) | Resistance training, HiMF training | 10 weeks, 3×/week, 7 exercises, 15-20 reps at 40-50% 1RM, weeks 2-10 3 sets of 8-20 reps at 50-85% 1RM | NA | HiMF control; or LoMF training; or LoMF control | BDNF levels | No changes in BDNF before to after in any group |
| Coelho, 2012 | Quasi-experimental | 48 | 100 | 70.5 (4.6) | Resistance training (physical therapy) | 10 weeks, 3×/week, 60 min, 2 weeks 50% of 1 RM, weeks 2-10 75% of 1RM | 180 min/week | Nonfrail vs prefrail | BDNF levels, plasma | ↑ BDNF levels |
| Vedovelli, 2017 | Open trial | 29 | 100 | 83 (6.53) | Aerobic, walking + resistance training | 12 weeks, 3×/week, 60 min, 2 weeks resistance-50% of 1RM increased to >/= 75% of 1RM by 3rd week, aerobic: 75-85% of HR max | 180 min/week | No exercise | BDNF serum levels | ↑ in BDNF levels for the intervention group |
| Forti, 2014 | Non-RCT | 40 | 45 | 65.69 | Resistance training | 12 weeks, 3×/week, 60 min, 50% of 1RM up to 70-80% of 1RM | 180 min/week | No exercise | BDNF serum, basal levels | No change in BDNF |
| Forti, 2015 | RCT | 49 | 54 | 68 (5) | Resistance training, high intensity | 12 weeks, 3×/week, HIGH: 2 sets, 10-15 reps of 80% 1RM; LOW: 1 set of 80-100 reps at 20% of RM, LOX MIXED: 60 reps at 20% of 1RM and immediately after (no rest) resistance increased to 40% of 1RM for 10-20 reps | NA | Resistance training, low intensity or mixed low resistance | BDNF, serum levels | No time x group interaction |
| Matura, 2017 | RCT | 53 | 43.4 | 75.3 (7.2) | Aerobic, cycle ergometer | 12 weeks, 3×/week, 30 min, progressive workload based on VT1 (64 ± 9% VO2max) | 90 min/week | Waiting list control group | BDNF, venous blood sample | No change in BDNF serum levels |
| Hvid, 2017 | RCT | 47 | 55 | 82.7 (5.4) | High-intensity power | 12 weeks, 2×/week, 3 sets 70% of 1RM (10 reps for weeks 1-7) 80% 1RM (weeks 8-12, 8 reps) | NA | No intervention | BDNF (mature BDNF, precursor proBDNF, total BDNF), serum levels at fasting | No change in BDNF serum levels |
| Prestes, 2014 | Open trial | 49 | 100 | 65.52 (4.72)/69.2 (6.05) | Resistance training with periodization (linear or undulating) | 16 weeks, 2×/week, 40-50 min, 3 sets to concentric failure, 12-14 RM to 6-8 RM) | 80-100 min/week | Control group | BDNF, serum levels |
↑ Percent in BDNF serum concentration in high responders compared to medium and low responders ↑ Serum concentrations of BDNF in the high and medium responders after intervention and ↓ in low responders |
| Vaughan, 2014 | RCT | 49 | 100 | 69 (3.1) | Aerobic, resistance, and motor fitness, | 16 weeks, 2×/week, 60 min | 120 min/week | Waiting list control group | BDNF, plasma levels |
↑ BDNF levels in the intervention group from 4.5 to 5.2 ↓ BDNF levels in the control group 5.6 to 4.7 |
| Maass, 2015 | Pseudo-RCT | 40 | 55 | 68.4 (4.3) | Aerobic, walking or running on a treadmill | 12 weeks, 3×/week, 40 min, 65-80% THR | 120 min/week | Indoor progressive-muscle relaxation/stretching | IGF-1, VEGF, and BDNF level | No changes in VEGF, IGF-1, and BDNF (no main or interaction effects) |
| Baker, 2010 | RCT | 28 | 50 | 71 (7.5) | Aerobic, treadmill, bike, or elliptical | 26 weeks, 4×/week, 45-60 min, 75-85% of HR reserve | 180-240 min/week | Stretching and balance group | BDNF, IGF, plasma levels |
↑ BDNF for the stretching group ↓ BDNF for the aerobic group |
| Rehfeld, 2018 | RCT | 38 | 50 | 63-80 | Dancing | 26 weeks, 2×/week, 90 min, new dance routines every second week | 180 min/week | Sport group (endurance, resistance–endurance, and flexibility) | Serum and plasma BDNF | ↑ BDNF plasma levels (not serum) in the dance group only plasma |
| Ruscheweyh, 2011 | RCT | 62 | 69.3 | 60.2 (6.6) | G1: aerobic, Nordic walking; G2: aerobic, gymnastics | 26 weeks, 3-5×/week, 50 min, G1: 50-60%, G2: 30-40% THR |
G1: 141 (30) G2: 138 (27) min/week |
No intervention control group | BDNF, serum blood levels | No changes in BDNF |
| Leckie, 2014 | RCT | 92 | 64.1 | 66.82 (5.59) | Aerobic, walking | 52 weeks, 3×/week, 10-40 min (10 min, increased to 40 by week 7), 50-60 to 60-75% THR | 120 min/week | Stretching and toning group | BDNF serum levels (fasting) |
↑ BDNF levels for the intervention group individuals > 65 years ↓ BDNF for the control group > 65 years |
| Erickson, 2011 | RCT | 120 | 73 | 67.6 (5.81) | Aerobic, walking | 52 weeks, 3×/week, 10-40 min (10 min, increased to 40 by week 7), 50-60 to 60-75% THR | 120 min/week | Stretching control group | BDNF, serum levels | No changes in BDNF levels (no time x group interaction) |
| Voss, 2013 | RCT | 65 | 73 | 66.3 | Aerobic, indoor walking | 52 weeks, 3×/week, 10-40 min (10 min, increased to 40 by week 7), 50-60 to 60-75% THR | 120 min/week | Flexibility, toning, and balance group | BDNF, IGF, and VEGF serum blood levels | No changes in BDNF, IGF, and VEGF |
| Vale, 2009 | Open trial | 35 | 100 | 68.08 (3.37)/68.69 (4.7) | Resistance or aerobic, aquatic exercise | 12 weeks, 3×/week, 50 min, moderate to high, 50% to 75-85% 1RM (resistance); light to moderate RPE (aerobic) | 150 min/week | Regular activity | IGF-1, blood serum levels |
↑ IGF-1 in strength training only No changes in aquatic or control |
| Banitalebi, 2018 | RCT | 40 | 100 | 67.35 (1.4) | G1: resistance + aerobic; G2: aerobic + resistance; G3: interval resistance–aerobic | 12 weeks, 3×/week, 50 min, moderate- to high-intensity (aerobic) and moderate resistance training | 150 min/week | Control group | IGF-1, blood levels fasting state |
No between-group differences in IGF-1 ↑ IGF-1 within-group differences for aerobic + resistance and resistance + aerobic groups |
| Cassilhas, 2007 | RCT | 62 | 0 | 69.01 (1.1)/68.4 (.67) | Resistance, moderate or high intensity | 24 weeks, 3×/week, 60 min, moderate (50% 1RM) and high intensity (80% 1RM) | 180 min/week | Warm-up and stretching without overload 1×/week | IGF-1, blood serum levels | ↑ IGF-1 in both experimental groups related to the control |
| Hofmann, 2016 | RCT | 91 | 100 | 83.6 | Progressive resistance training with bands | 26 weeks, 2×/week, 60 min, yellow and then red and black resistance band | 180 min/week | Cognitive training | IGF-1, blood serum levels | No changes in IGF-1 |
| Mason, 2013 | RCT | 35 | 100 | 58 | Diet, exercise, diet + exercise | 52 weeks, 5×/week (3x supervised + 2x home), 45 min, moderate to vigorous 70-85% THR | 125 min/week + 90 min/week | Control no intervention | IGF-1, blood serum levels at fasting | No changes in IGF-1 comparing exercisers to control |
| Tsai, 2015 | RCT | 48 | 0 | 71.4 (3.79) | Resistance | 52 weeks, 3×/week 60 min, high-intensity resistance training (75-80% of 1RM, 3 sets × 20 reps) | 180 min/week | Nonspecific exercise intervention or group activity | IGF-1, blood serum levels | ↑ IGF-1 in the exercise group |
| Ogawa, 2010 | Before and after trial | 21 | 100 | 85 (4.5) | Resistance | 12 weeks, at least 1×/week, 40 min, low intensity progressed by participant request | At least 40 min/week | No control group | IGF-1 and VEGF, blood serum levels at fasting | No changes in IGF-1 or VEGF |
| Seo, 2012 | RCT | 22 | 100 | 55 | Aerobic, walking or combined (aerobic–resistance) | 12 weeks, 3×/week 60 min, moderate aerobic intensity (60-80% of HR reserve) and resistance (50-70% of 1RM) | 180 min/week | Stretching control group | IGF-1, blood serum levels | No main effects for IGF-1 |
n = number of subjects; S.D. = standard deviation; RCT = randomized controlled trials; NR = not reported; NA = not applied; THR = target heart rate; RPE = rate of perceived exertion; BDNF = brain-derived neurotrophic factor; IGF-1 = insulin-like growth factor; VEGF = vascular endothelial growth factor; HiMF = high number of metabolic risk factors; LoMF = low number of metabolic risk factors; 1RM = one-repetition maximum; VT1 = first ventilatory threshold; VO2max = maximum rate of oxygen consumption; ↑ = significant increase; ↓ = significant decrease