title: Effects of resistance training on cardiovascular responses to lower body negative pressure in the elderly.
abstract: The purpose of the present study was to determine whether resistance training alters the cardiovascular responses to submaximal lower body negative pressure (LBNP) in the elderly. Twenty-one subjects were randomized into a control (C: n=10; 70 +/- 3 years, mean +/- SD) or a resistance training (TR: n=11; 67 +/- 7 years) group. Subjects in the TR underwent 12 weeks of training consisting of three sets of 8-12 contractions at approximately 60-80% of their initial maximal one repetition, three times per week, on 10 different machines. Before (Pre) and after (Post) training, all subjects underwent exposures of LBNP of -10, -20 and -40 Torr and muscle biopsy sampling at the vastus lateralis. TR increased (P< or =0.05) knee extension (Pre=379 +/- 140 N, Post=534 +/- 182 N) and chest press (Pre=349 +/- 137 N, Post=480 +/- 192 N) strength. Neither body weight nor percentage body fat were altered (P >0.05) by training. Resistance training increased (P< or =0.05) cross-sectional area in both Type I (4203 +/- 1196 to 5248 +/- 1728 microm2) and Type II (3375 +/- 1027 to 4286 +/- 1892 microm2) muscle fibres. Forearm blood flow, forearm vascular conductance, mean arterial pressure, and heart-rate responses to LBNP were not altered by the training. These data suggest that the cardiovascular responses of elderly to LBNP are unaffected by 12 weeks of whole-body resistance training despite increases in muscle strength and size.
authors.affiliation: Department of Nutrition, Food and Exercise Sciences, Florida State University, 436 Sandels Building, Tallahassee, FL 32306, USA.
authors.forename: L B
authors.initials: LB
authors.lastname: Panton
authors.forename: W D
authors.initials: WD
authors.lastname: Franke
authors.forename: D A
authors.initials: DA
authors.lastname: Bleil
authors.forename: S M
authors.initials: SM
authors.lastname: Baier
authors.forename: D S
authors.initials: DS
authors.lastname: King
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001706:Biopsy; D001794:Blood Pressure / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D005260:Female; D005542:Forearm / Q000098:blood supply; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008150:Lower Body Negative Pressure; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D012885:Skinfold Thickness; D014891:Weight Lifting