title: Metabolic responses to the seated calf press exercise performed against inertial resistance.
abstract: BACKGROUND
  Future in-flight strength training devices may use inertial resistance to abate mass and strength losses to muscle groups such as the triceps surae, which incurs pronounced deficits from space travel. Yet little data exist regarding physiological outcomes to triceps surae exercise performed against inertial resistance. Two sets of subjects were employed to note either blood lactate (La-) or net caloric cost responses to seated calf presses done on an inertial resistance ergometer.
  
  
  METHODS
  Both sets of subjects performed 3 identical 3-set 10-repetition workouts. Blood La- measurements were made pre- and 5 min post-exercise. During workouts, breath-by-breath O2 uptake values were also recorded to help determine the net caloric cost of exercise.
  
  
  RESULTS
  Compared to pre-exercise (mean +/- SEM) blood La- (2.01 +/- 0.08 mmol x L(-1)) values, post-exercise (4.73 +/- 0.24 mmol x L(-1)) measurements showed a significant increase. Delta (post/pre differences) La- correlated significantly (r = 0.31-0.34) to several workout performance measures. Net caloric cost averaged 52.82 +/- 3.26 kcals for workouts; multivariate regression showed a subject's height, body mass, and body surface area described the variance associated with energy expenditure.
  
  
  CONCLUSIONS
  Workouts evoked minimal energy expenditure, though anaerobic glycolysis likely played a major role in ATP resynthesis. Metabolic and exercise performance measures were likely influenced by series elastic element involvement of the triceps surae-Achilles tendon complex. Ergometer calf presses provided a high-intensity workout stimulus with a minimal metabolic cost.
authors.affiliation: Exercise and Sport Sciences Program, the University of Tulsa, Tulsa, OK 74104, USA. john-caruso@utulsa.edu
authors.forename: John F
authors.initials: JF
authors.lastname: Caruso
authors.forename: Jacquelyn C
authors.initials: JC
authors.lastname: Herron
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hernandez
authors.forename: Aaron
authors.initials: A
authors.lastname: Porter
authors.forename: Torrey
authors.initials: T
authors.lastname: Schweickert
authors.forename: Tommy F
authors.initials: TF
authors.lastname: Manning
mesh_terms: D000337:Aerospace Medicine; D001823:Body Composition / Q000502:physiology; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D004734:Energy Metabolism / Q000502:physiology*; D016552:Ergometry; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*
chemical_list: D019344:Lactic Acid