title: Effects of high intensity resistance aquatic training on body composition and walking speed in women with mild knee osteoarthritis: a 4-month RCT with 12-month follow-up.
abstract: To investigate the effects of 4-months intensive aquatic resistance training on body composition and walking speed in post-menopausal women with mild knee osteoarthritis (OA), immediately after intervention and after 12-months follow-up. Additionally, influence of leisure time physical activity (LTPA) will be investigated.
  
  
  
  This randomised clinical trial assigned eighty-seven volunteer postmenopausal women into two study arms. The intervention group (n = 43) participated in 48 supervised intensive aquatic resistance training sessions over 4-months while the control group (n = 44) maintained normal physical activity. Eighty four participants continued into the 12-months' follow-up period. Body composition was measured with dual-energy X-ray absorptiometry (DXA). Walking speed over 2 km and the knee injury and osteoarthritis outcome score (KOOS) were measured. LTPA was recorded with self-reported diaries.
  
  
  
  After the 4-month intervention there was a significant decrease (P = 0.002) in fat mass (mean change: -1.17 kg; 95% CI: -2.00 to -0.43) and increase (P = 0.002) in walking speed (0.052 m/s; 95% CI: 0.018 to 0.086) in favour of the intervention group. Body composition returned to baseline after 12-months. In contrast, increased walking speed was maintained (0.046 m/s; 95% CI 0.006 to 0.086, P = 0.032). No change was seen in lean mass or KOOS. Daily LTPA over the 16-months had a significant effect (P = 0.007) on fat mass loss (f2= 0.05) but no effect on walking speed.
  
  
  
  Our findings show that high intensity aquatic resistance training decreases fat mass and improves walking speed in post-menopausal women with mild knee OA. Only improvements in walking speed were maintained at 12-months follow-up. Higher levels of LTPA were associated with fat mass loss.
  
  
  
  ISRCTN65346593.
authors.affiliation: Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland. Electronic address: ben.waller@jyu.fi.
authors.forename: B
authors.initials: B
authors.lastname: Waller
authors.affiliation: Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland. Electronic address: matti.munukka@jyu.fi.
authors.forename: M
authors.initials: M
authors.lastname: Munukka
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia. Electronic address: t.rantalainen@deakin.edu.au.
authors.forename: T
authors.initials: T
authors.lastname: Rantalainen
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland. Electronic address: eveliina.lammentausta@ppshp.fi.
authors.forename: E
authors.initials: E
authors.lastname: Lammentausta
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland; Medical Research Center, University of Oulu and Oulu University Hospital, Finland. Electronic address: miika.nieminen@oulu.fi.
authors.forename: M T
authors.initials: MT
authors.lastname: Nieminen
authors.affiliation: Department of Orthopedics and Traumatology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. Electronic address: ilkka.kiviranta@helsinki.fi.
authors.forename: I
authors.initials: I
authors.lastname: Kiviranta
authors.affiliation: Department of General Practice and Primary Health Care, University of Helsinki, Helsinki, Finland; Unit of Primary Health Care, Kuopio University Hospital, Kuopio, Finland. Electronic address: hannu.kautiainen@medcare.fi.
authors.forename: H
authors.initials: H
authors.lastname: Kautiainen
authors.affiliation: Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland. Electronic address: arja.h.hakkinen@jyu.fi.
authors.forename: A
authors.initials: A
authors.lastname: Häkkinen
authors.affiliation: Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland. Electronic address: urho.m.kujala@jyu.fi.
authors.forename: U M
authors.initials: UM
authors.lastname: Kujala
authors.affiliation: Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland. Electronic address: ari.o.heinonen@jyu.fi.
authors.forename: A
authors.initials: A
authors.lastname: Heinonen
mesh_terms: D000368:Aged; D001823:Body Composition / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006875:Hydrotherapy / Q000379:methods*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000628:therapy*; D010349:Patient Compliance; D005082:Physical Exertion / Q000502:physiology; D017698:Postmenopause / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D000072797:Walking Speed / Q000502:physiology*
keywords: Aquatic exercise; Body composition; Osteoarthritis; Walking speed