TITLE

Manipulating training intensity and volume in already well-trained rats: effect on skeletal muscle oxidative and glycolytic enzymes and buffering capacity

AUTHOR(S)
Laursen, Paul B.; Marsh, Susan A.; Jenkins, David G.; Coombes, Jeff S.
PUB. DATE
June 2007
SOURCE
Applied Physiology, Nutrition & Metabolism;Jun2007, Vol. 32 Issue 3, p434
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Well-trained endurance athletes undergo periods of high-intensity interval training (HIT) or high-volume training (HVT) to improve exercise performance, but little is known about the mechanistic changes that occur during this time. The purpose of this study was to examine the influence of HIT and HVT on the activities of citrate synthase (CS) and phosphofructokinase (PFK), and on intramuscular buffering capacity (βm) in already well-trained rats. At 4 weeks of age, Wistar rats were divided into sedentary (SED; n = 18) and exercise training groups (n = 38). Following a 10 week preliminary training program, trained rats were divided randomly into 3 further groups that completed 4 additional weeks of continued endurance (CON, n = 14), high-intensity training (HIT, n = 12), or high-volume training (HVT, n = 12). Soleus (SOL), red and white gastrocnemius (RG and WG), and red and white vastus (RV and WV) muscles were removed 24–48 h after a final run-to-fatigue performance test (30 m·min–1; 25% grade) to determine the activities of CS, PFK, and βm. No differences in run time to exhaustion were found between the groups. However the HIT group possessed CS and PFK activities and βm in WV muscle that were 60%, 24%, and 10% higher, respectively (all p < 0.05), compared with the HVT group; differences were not found between the HIT and CON groups. Although no differences in run performance were found, HIT compared with HVT in already well-trained rats resulted in significantly higher oxidative and glycolytic capacities of fast-contracting fibres. No differences were shown in fast-contracting muscle between HIT and CON.
ACCESSION #
25479926

 

Related Articles

  • High-Intensity Interval Training: A Sprint or Nine Saves Time? Selfridge, Nancy J. // Integrative Medicine Alert;Aug2012, Vol. 15 Issue 8, p88 

    The article offers research-based results of the impact of high-intensity interval training (HIT). A study by Gibala et al. showed that a Wingate HIT protocol resulted in increased mitochondrial enzymes and skeletal muscle oxidative capacity. Another study by Kessler et al. reviewed research...

  • The effects of high-intensity exercise on skeletal muscle neutrophil myeloperoxidase in untrained and trained rats. Morozov, Vladimir L.; Tsyplenkov, Pavel V.; Golberg, Natalia D.; Kalinski, Michael I.; Morozov, Vladimir I // European Journal of Applied Physiology;Aug2006, Vol. 97 Issue 6, p716 

    The primary purpose of this study was to examine the effects of high-intensity acute exercise on neutrophil infiltration in different muscle fiber types of untrained rats and to compare postexercise neutrophil accumulation in muscles of untrained and trained animals. The effect of high-intensity...

  • INSTEAD OF REHABILITATION, THINK PREHABILITATION.  // American Fitness;May/Jun2010, Vol. 28 Issue 3, p55 

    The article discusses the importance of preventing sports-related injuries rather than rehabilitating them. It says that fitness trainers can provide their clients with appropriate methods to strengthen the musculoskeletal system, which can actually help prevent noncontact injuries like strains...

  • Three-dimensional musculoskeletal modelling of the seated row resistance-training exercise. Nolte, K.; Krüger, P. E.; Els, P. S.; Nolte, H. W. // South African Journal of Sports Medicine;Sep2013, Vol. 25 Issue 3, p67 

    Objective. To evaluate whether three-dimensional (3D) musculoskeletal modelling could be effective in assessing the safety and efficacy of exercising on a seated row resistance-training machine. The focus of the evaluation was on biomechanical and anthropometric considerations of the end user....

  • Effects Of High-Intensity Strength Training On Steady-State Myosin Heavy Chain Isoform Mrna Expression. Willoughby, Darryn S.; Pelsue, Stephen // Journal of Exercise Physiology Online;Oct2000, Vol. 3 Issue 4, p13 

    The purpose of this study was to determine steady-state myosin heavy chain (MHC) isoform (Types I, IIa, and IIx) mRNA abundance in skeletal muscle after 8 wks of high-intensity strength training. Twelve untrained males were randomly assigned to either a control (CON) or strength training (STR)...

  • Effects of Locomotion-Training based on Theories of Behavioral Science –Sustainability of Exercise by Community-dwelling Elderly Women–. Hosoi, Toshiki; Arai, Tomoyuki; Fujita, Hiroaki // Rigakuryoho Kagaku;2011, Vol. 26 Issue 4, p511 

    [Purpose] The purpose of this study was to verify that exercise program based on theories of behavioral science, Loco-tre BBS, led to the sustainability of exercise by community-dwelling elderly women. [Subjects and Method] The subjects were 12 elderly women living in Saitama Prefecture,...

  • Interaction among Skeletal Muscle Metabolic Energy Systems during Intense Exercise. Baker, Julien S.; ClareMcCormick, Marie; Robergs, Robert A. // Journal of Nutrition & Metabolism;2010, p1 

    High-intensity exercise can result in up to a 1,000-fold increase in the rate of ATP demand compared to that at rest (Newsholme et al., 1983). To sustain muscle contraction, ATP needs to be regenerated at a rate complementary to ATP demand. Three energy systems function to replenish ATP in...

  • Altered patterns of reflex excitability, balance, and locomotion following spinal cord injury and locomotor training. Bose, Prodip K.; Hou, Jiamei; Parmer, Ronald; Reier, Paul J.; Thompson, Floyd J. // Frontiers in Physiology;Jul2012, Vol. 3, p1 

    Spasticity is an important problem that complicates daily living in many individuals with spinal cord injury (SCI). While previous studies in human and animals revealed signifi cant improvements in locomotor ability with treadmill locomotor training, it is not known to what extent locomotor...

  • THE ROLE OF INSTABILITY WITH RESISTANCE TRAINING. Behm, David G.; Anderson, Kenneth G. // Journal of Strength & Conditioning Research (Allen Press Publish;Aug2006, Vol. 20 Issue 3, p716 

    There are many instances in daily life and sport in which force must be exerted when an individual performing the task is in an unstable condition. Instability can decrease the externally-measured force output of a muscle while maintaining high muscle activation. The high muscle activation of...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics