title: Load-Specific Inflammation Mediating Effects of Resistance Training in Older Persons.
abstract: Little is known about the effects of resistance training (RT) on circulating cytokines in older adults. Also, dose-response relationships remain unclear. This study investigated the impact of RT at different external loads on circulating inflammatory mediators in older community-dwelling individuals.
  
  
  
  Fifty-six community-dwelling older (68 ± 5 years) volunteers were randomized to 12 weeks of supervised RT (×3/week) at either high-resistance training [8 males, 10 females, 2 × 10-15 repetitions at 80% 1 repetition maximum (RM)], low-resistance training (9 males, 10 females, 1 × 80-100 repetitions at 20% 1 RM), or mixed low-resistance training (9 males, 10 females, 1 × 60 repetitions at 20% 1 RM followed by 1 × 10-20 repetitions at 40% 1 RM). Serum was available from 51 out of 56 participants at baseline and after 12 weeks for determination of interleukin (IL)-6, IL-8, IL-10, IL-1β, soluble tumor necrosis factor receptor (sTNFR)1, granulocyte macrophage colony-stimulating factor, and IL-1 receptor antagonist (ra).
  
  
  
  Twelve weeks of RT significantly increased sTNFR1 from 2.48 ± 0.57 ng/mL to 2.58 ± 0.59 ng/mL (overall time-effect P = .033) and Log IL-8 from 0.38 ± 0.18 pg/mL to 0.53 ± 0.32 pg/mL (overall time-effect P = .007). No time X group interaction (P = .916) was observed. In males of the high-resistance training group, there was an increase in Log IL-8 (from 0.45 ± 0.16 pg/mL to 0.68 ± 0.19 pg/mL; P = .005) and IL-1ra (from 68.60 ± 24.12 pg/mL to 79.56 ± 29.07 pg/mL; P = .007). No significant changes were found for the other markers.
  
  
  
  Our results show that 12 weeks of supervised RT induced an overall significant increase of circulating IL-8 and sTNFR1, independently from the external load applied. We suggest that exercising until volitional fatigue is the main trigger for exercise-induced responses. However, training at high external load also increased anti-inflammatory IL-1ra in male participants, which might be beneficial in combating low-grade inflammation.
authors.affiliation: Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium; Frailty in Aging Research (FRIA) Group, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Louis Nuvagah
authors.initials: LN
authors.lastname: Forti
authors.affiliation: Physical Activity, Sports, and Health Research Group, Department of Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
authors.forename: Evelien
authors.initials: E
authors.lastname: Van Roie
authors.affiliation: Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium; Frailty in Aging Research (FRIA) Group, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Rose
authors.initials: R
authors.lastname: Njemini
authors.affiliation: Radiology Section, Department of Morphology and Medical Imaging, Faculty of Medicine, KU Leuven, Leuven, Belgium.
authors.forename: Walter
authors.initials: W
authors.lastname: Coudyzer
authors.affiliation: Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium; Frailty in Aging Research (FRIA) Group, Vrije Universiteit Brussel, Brussels, Belgium; Department of Geriatrics, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Ingo
authors.initials: I
authors.lastname: Beyer
authors.affiliation: Physical Activity, Sports, and Health Research Group, Department of Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Delecluse
authors.affiliation: Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium; Frailty in Aging Research (FRIA) Group, Vrije Universiteit Brussel, Brussels, Belgium; Department of Geriatrics, Universitair Ziekenhuis Brussel, Brussels, Belgium. Electronic address: ivan.bautmans@vub.ac.be.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bautmans
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000517:prevention & control; D007558:Italy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D055070:Resistance Training / Q000379:methods
chemical_list: D015415:Biomarkers; D016207:Cytokines
keywords: Cytokines; aged; resistance training; training load