title: Leg strength is associated with ventilatory efficiency in older women.
abstract: The aim of the present study was to determine if leg function is associated with ventilatory efficiency during exercise in healthy older adults. 24 women and 18 men aged 60-80 years performed treadmill exercise to fatigue for calculation of ventilatory efficiency using the ratio of ventilation to carbon dioxide at the anaerobic threshold (VE/VCO₂@AT). On a separate day, participants performed leg strength testing and graded single-leg knee extension exercise. The VE/VCO₂@AT was higher in women than men (33±3 vs. 30±3; p=0.03). After adjustment for age and VO(₂max), leg strength (knee extensor isometric force) was inversely associated with VE/VCO₂@AT in women (r= - 0.44, p=0.03) while no relationships were found for men. Strength-matched women and men had similar VE/VCO₂@AT indicating that the correlation between leg strength and VE/VCO₂@AT was strength- but not sex-specific. During knee extensor exercise, women with lower leg strength had increased VE/VCO₂ slope across 0-15 W as compared to higher strength women (38±8 vs. 31±3; p<0.05), while no differences were found for men. These results find leg strength to be associated with ventilatory responses to exercise in healthy older women, a finding that might be related to lower leg strength in women than men.
authors.affiliation: Health, Exercise and Sport Sciences, Texas Tech University, Lubbock, USA.
authors.forename: J U
authors.initials: JU
authors.lastname: Gonzales
authors.forename: S H
authors.initials: SH
authors.lastname: Tucker
authors.forename: M J
authors.initials: MJ
authors.lastname: Kalasky
authors.forename: D N
authors.initials: DN
authors.lastname: Proctor
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015308:Anaerobic Threshold; D002245:Carbon Dioxide / Q000378:metabolism; D005080:Exercise Test; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D007866:Leg; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D012737:Sex Factors
chemical_list: D002245:Carbon Dioxide