title: Dose-and gender-specific effects of resistance training on circulating levels of brain derived neurotrophic factor (BDNF) in community-dwelling older adults.
abstract: BACKGROUND
  BDNF is known to induce neuroplasticity and low circulating levels have been related to neuronal loss in older persons. Physical exercise is thought to trigger BDNF-induced neuroplasticity, but conflicting observations have been reported regarding the effects of resistance training on circulating BDNF in the elderly. These conflicting observations might reflect dose-and gender-specific differences.
  
  
  METHODS
  Fifty-six apparently healthy elderly (68 ± 5 years) participants were randomized to 12 weeks of resistance training (3×/week) at either high-resistance (HIGH, 8 Males, 10 Females, 2 × 10-15 repetitions at 80% 1 RM), low-resistance (LOW, 9 Males, 10 Females, 1 × 80-100 repetitions at 20% 1 RM), or mixed low-resistance (LOW+, 9 Males, 10 Females, 1 × 60 repetitions at 20% 1 RM followed by 1 × 10-20 repetitions at 40% 1 RM). Serum was collected for BDNF assay at baseline and after 12 weeks (24 h-48 h after the last training).
  
  
  RESULTS
  12 weeks of LOW+ exercise significantly increased BDNF levels in male (from 34.9 ± 10.7 ng/mL to 42.9 ± 11.9 ng/mL, time × group interaction p=0.013), but not in female participants. No significant change was observed in HIGH or LOW, neither in male nor female subjects.
  
  
  CONCLUSIONS
  Our results show that only the mixed-low-resistance training program with a very high number of repetitions at a sufficiently high external resistance was able to increase circulating BDNF in older male participants. Training to volitional fatigue might be necessary to obtain optimal results. Additional studies are needed to unravel the underlying mechanisms, as well as to confirm the observed gender difference.
authors: Gerontology (GERO) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Aging Research (FRIA) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium.
authors: Louis Nuvagah
authors: LN
authors: Forti
authors: Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, B-3001 Leuven, Belgium.
authors: Evelien
authors: E
authors: Van Roie
authors: Gerontology (GERO) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Aging Research (FRIA) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium.
authors: Rose
authors: R
authors: Njemini
authors: Radiology Department, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium.
authors: Walter
authors: W
authors: Coudyzer
authors: Gerontology (GERO) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Aging Research (FRIA) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Department of Geriatrics, UniversitairZiekenhuis Brussel, Laarbeeklaan 101, B-1090 Brussels, Belgium.
authors: Ingo
authors: I
authors: Beyer
authors: Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, B-3001 Leuven, Belgium.
authors: Christophe
authors: C
authors: Delecluse
authors: Gerontology (GERO) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Aging Research (FRIA) Department, VrijeUniversiteitBrussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Department of Geriatrics, UniversitairZiekenhuis Brussel, Laarbeeklaan 101, B-1090 Brussels, Belgium. Electronic address: ivan.bautmans@vub.ac.be.
authors: Ivan
authors: I
authors: Bautmans
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D012727:Sex Characteristics
chemical_list: D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human
keywords: BDNF; Muscle fatigue; Older persons; Resistance training; Trainings load