title: Efficacy of manual versus free-weight training to improve maximal strength and performance for microgravity conditions.
abstract: We tested a simple and compact device designed for manual resistance training in conditions of microgravity (Self-Powered Rope Trainer Duo (SPoRT Duo)) to increase muscle performance. Twenty-four participants (20.8 ± 2.1 years) were randomly assigned to a manual resistance group (n = 12) and a free-weight group (n = 12). Participants performed eight exercises (three sets; 8-12 efforts) either with free weights or the SPoRT Duo twice a week for 6 weeks. Maximal isometric force of trunk flexion, back extension and chest press increased (P at least 0.01, d at least 0.52) both in the manual resistance group (18.4% ± 15.0%; 32.7% ± 22.7%; 15.3% ± 9.7%) and free-weight group (18.0% ± 13.9%; 26.6% ± 28.9%; 13.3% ± 7.6%). The change in maximal isometric force of wide grip row in both groups (d at best 0.38) did not reach statistical significance (P at best 0.08). The squat one-repetition-maximum increased in the manual resistance group (29.8% ± 22.1%) and the free-weight group (32.4% ± 26.6%). Jump height, determined by a jump-and-reach test, increased in the free-weight group (9.8% ± 13.2%) but not in the manual resistance group (2.0% ± 8.5%). Manual resistance training was equally effective in increasing strength as traditional resistance training with free weights. This apparatus is a useful addition to current in-flight exercise systems.
authors.affiliation: a Institute of Training Science and Sport Informatics , German Sport University Cologne , Cologne , Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Behringer
authors.affiliation: a Institute of Training Science and Sport Informatics , German Sport University Cologne , Cologne , Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schüren
authors.affiliation: a Institute of Training Science and Sport Informatics , German Sport University Cologne , Cologne , Germany.
authors.forename: Molly
authors.initials: M
authors.lastname: McCourt
authors.affiliation: a Institute of Training Science and Sport Informatics , German Sport University Cologne , Cologne , Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Mester
mesh_terms: D006801:Humans; D007537:Isometric Contraction; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D063806:Myalgia / Q000209:etiology; D010806:Physical Education and Training / Q000379:methods*; D055070:Resistance Training / Q000379:methods*; D019876:Sports Equipment; D014891:Weight Lifting / Q000502:physiology*; D014893:Weightlessness; D055815:Young Adult
keywords: manual resistance training; maximal isometric force; microgravity; one-repetition-maximum; weightlessness