A minimalistic model of resistance training : effects on skeletal muscle function during unloading

Cardinal Scholar

Show simple item record

dc.contributor.advisor Trappe, Scott William en_US
dc.contributor.author Schulze, Kimberley E. en_US
dc.date.accessioned 2011-06-03T19:30:51Z
dc.date.available 2011-06-03T19:30:51Z
dc.date.created 1999 en_US
dc.date.issued 1999
dc.identifier LD2489.Z68 1999 .S38 en_US
dc.identifier.uri http://cardinalscholar.bsu.edu/handle/handle/180552
dc.description.abstract Since astronaut time and energy are at a premium, effective countermeasures must be designed to maximize benefits while minimizing time/energy cost. Therefore, our intent was to design and evaluate a low volume, high intensity resistance training program (RTP) on the preservation of knee extensor and plantar flexor size, strength and neuromuscular function in response to unloading. A total of 32 subjects participated. Sixteen men underwent 21 days of unilateral lower limb suspension (ULLS) and were assigned to control (no RTP) (ULLS-CON, n=8) or countermeasures (ULLS-CM, n=8). The remaining subjects were ambulatory for 21 days and were assigned to no RTP (n=8) or countermeasures (n=8). Countermeasure subjects performed RTP every third day during the suspension period (total=6). The RTP consisted of 2 maximal isometric contractions (MVC), 1 set of 10 concentric/eccentric isotonic repetitions, and 1 set to exhaustion, at 80% of 1-repetition maximum (1RM). There was no change in muscle function in ambulatory subjects. Whole muscle cross sectional area (CSA) measured by computed tomography (CT) decreased 7% (thigh) and 7.5% (calf) in ULLS-CON (p<0.05), and was unchanged in ULLS-CM. MVC decreased 16.5% in both quadricep and calf muscles in ULLS-CON (p<0.05) and increased 6% in the quadricep of ULLSCM (p<0.05). Maximal concentric (CNC) and eccentric (ECC) isokinetic strength decreased an average of 18% and 17% in the knee extensors and plantar flexors of ULLS-CON, respectively (p<0.05) and was unchanged in ULLS-CM. 1RM decreased 16% in both quadricep and calf of ULLS-CON (p<0.05) and was unchanged in ULLSCM. Knee extensor work capacity, evaluated during 30 maximal CNC contractions (3.14 rad•sec-'), decreased 18% in ULLS-CON (p<0.05). Neural activation of knee extensors and plantar flexors was measured by electromyography (EMG). Submaximal v.lat, v.med, gast and sol EMG increased in ULLS-CON (p<0.05) and was unaltered in ULLSCM. Maximal EMG decreased 20% and 26% in v.1at and v.med, respectively in ULLSCON (p<0.05). ULLS-CM showed a 15% and 28% increase in v.med and gast maximal EMG (p<0.05). These data suggest knee extensor and plantar flexor muscle size, strength and neuromuscular function were preserved during unloading using a low volume, high intensity RTP performed every third day. en_US
dc.description.sponsorship School of Physical Education
dc.format.extent ix, 128 leaves : ill. ; 28 cm. en_US
dc.source Virtual Press en_US
dc.subject.lcsh Isometric exercise -- Physiological aspects. en_US
dc.subject.lcsh Astronauts -- Physiology. en_US
dc.subject.lcsh Musculoskeletal system -- Effect of space flight on. en_US
dc.subject.lcsh Reduced gravity environments. en_US
dc.title A minimalistic model of resistance training : effects on skeletal muscle function during unloading en_US
dc.description.degree Thesis (Ph. D.) en_US
dc.identifier.cardcat-url http://liblink.bsu.edu/catkey/1170962 en_US


Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

  • Doctoral Dissertations [3248]
    Doctoral dissertations submitted to the Graduate School by Ball State University doctoral candidates in partial fulfillment of degree requirements.

Show simple item record

Search Cardinal Scholar


Browse

My Account