Facebook X (Twitter) Instagram
    ELITETRACK
    • Home
    • Articles
      • Endurance
      • Flexibility
      • Hurdles
      • Jumps
        • High Jump
        • Long Jump
        • Pole Vault
        • Triple Jump
      • Multi-Events
      • Periodization
      • Relays
      • Sports Science
        • Biomechanics
        • Coaching Science
        • Exercise Physiology
        • Muscle Dynamics
        • Nutrition
        • Restoration
        • Sport Psychology
      • Sprints
      • Strength Training
      • Throws
        • Discus
        • Hammer
        • Javelin
        • Shot Put
    • Blog
      • Mike Young’s Blog
      • Carl Valle’s Blog
      • John Evan’s Blog
      • Antonio Squillante’s Blog
      • Vern Gambetta’s Blog
      • John Grace’s Blog
      • Ryan Banta’s Blog
      • Guest Blog
    • Forums
    • Store
    • Log in
    ELITETRACK
    You are at:Home»Mike Young's Blog»“Marathon Mice” Spotlight a Rare Type of Muscle

    “Marathon Mice” Spotlight a Rare Type of Muscle

    0
    By Mike Young on January 3, 2007 Mike Young's Blog

    Here’s an interesting read by JR Minkel of Scientific American:

    Researchers have prompted mice to grow whole muscles from a normally rare type of muscle fiber, yielding rodents capable of running harder and for longer stretches of time than their unaltered compeers. Such animals may help to determine the role of this poorly understood type of fiber and to identify drugs capable of counteracting muscle-wasting diseases such as muscular dystrophy in people.

    Muscle fibers come in two general flavors–“slow-twitch” and “fast-twitch.” Slow-twitch fibers are redder (think beef or dark-meat chicken) and have more endurance than fast-twitch fibers (think pork or white meat), which contract faster but use energy less efficiently.

    The muscles of the newly created mice are composed of an intermediatetype of fiber that is usually present in muscles only in small amounts.The researchers inserted a hyperactive form of a mouse gene called PGC-1Binto growing embryos and found that this uncommon fiber, called IIX,became abundant in the resulting mice, at the expense of fast-twitchfibers.

    These IIX-rich animals had noticeably redder, slower-twitchmuscles and, as a result, were quite the little athletes, the groupreports in this month’s issue of the journal Cell Metabolism.They were able to run an average of 33 minutes before pooping out,compared with 26 minutes for their counterparts. “They did a lot betterthan their wild-type brethren,” says cardiologist Zoltan Arany ofHarvard Medical School, the study’s lead author. “It was veryimpressive.”

    Researchers believe that PGC-1Bproduces a protein that helps activate other proteins, which, in turn,stimulate the genes that make IIX fibers. Members of the same group ina 2002 study discovered that a related gene, PGC-1A, turns fast-twitch fibers (called IIB) into the slow-twitch varieties (I and IIA).

    Aranysays the findings could help shed light on the role of this type ofmuscle, which, until now, had been hard to pin down, because animalsnormally have relatively few IIX fibers. “These mice will be awonderful tool to study what IIX fibers are all about,” he says.Earlier research indicated, for example, that muscles spend time as IIXfibers when they transform from the fast-twitch IIB to slow-twitch IIA.

    Manipulating the type of fibers present in human muscle couldalso help treat muscle-wasting diseases such as muscular dystrophy,Arany says, because experiments have shown that slow-twitch fibers maybe more resistant to wasting.

    Discuss entry

    endurance activities metabolism research
    Share. Facebook Twitter Pinterest LinkedIn Tumblr Email

    Related Posts

    Why Triathlons Are Better Than Marathons

    Some Thoughts to Stimulate Thought

    The Endurance and Kick Transition of Mo Farah from Track to Road

    Like Us On Facebook
    - Facebook Members WordPress Plugin
    Highest Rated Posts
    • A Review of 400m Training Methods 79 votes, average: 4.92 out of 579 votes, average: 4.92 out of 579 votes, average: 4.92 out of 579 votes, average: 4.92 out of 579 votes, average: 4.92 out of 5 (4.92 out of 5)
    • 2008 Olympics: Usain’s Insane 100m 67 votes, average: 4.96 out of 567 votes, average: 4.96 out of 567 votes, average: 4.96 out of 567 votes, average: 4.96 out of 567 votes, average: 4.96 out of 5 (4.96 out of 5)
    • Top 10 Myths of Sprinting Mechanics 66 votes, average: 4.74 out of 566 votes, average: 4.74 out of 566 votes, average: 4.74 out of 566 votes, average: 4.74 out of 566 votes, average: 4.74 out of 5 (4.74 out of 5)
    • 14 reasons why Jamaica is the Sprint Capitol of the World 59 votes, average: 4.85 out of 559 votes, average: 4.85 out of 559 votes, average: 4.85 out of 559 votes, average: 4.85 out of 559 votes, average: 4.85 out of 5 (4.85 out of 5)
    • 12 Reasons to Squat Year Round 58 votes, average: 4.86 out of 558 votes, average: 4.86 out of 558 votes, average: 4.86 out of 558 votes, average: 4.86 out of 558 votes, average: 4.86 out of 5 (4.86 out of 5)
    • 6 Reasons Why All Athletes Should Sprint 63 votes, average: 4.32 out of 563 votes, average: 4.32 out of 563 votes, average: 4.32 out of 563 votes, average: 4.32 out of 563 votes, average: 4.32 out of 5 (4.32 out of 5)
    • 4 Tips for Keeping up with Sport Science Research 65 votes, average: 4.03 out of 565 votes, average: 4.03 out of 565 votes, average: 4.03 out of 565 votes, average: 4.03 out of 565 votes, average: 4.03 out of 5 (4.03 out of 5)
    • Loren Seagrave’s thoughts on Absolute Strength 54 votes, average: 4.80 out of 554 votes, average: 4.80 out of 554 votes, average: 4.80 out of 554 votes, average: 4.80 out of 554 votes, average: 4.80 out of 5 (4.80 out of 5)
    • 6 Reasons Why Jamaicans Dominate the Sprints 50 votes, average: 4.78 out of 550 votes, average: 4.78 out of 550 votes, average: 4.78 out of 550 votes, average: 4.78 out of 550 votes, average: 4.78 out of 5 (4.78 out of 5)
    • Developing Endurance in Speed-Power Athletes 58 votes, average: 4.09 out of 558 votes, average: 4.09 out of 558 votes, average: 4.09 out of 558 votes, average: 4.09 out of 558 votes, average: 4.09 out of 5 (4.09 out of 5)
    Recent Topics
    • ?Where I can start in multievents trainig?
    • Josh Hurlebaus Masters Training Log
    • How and when do hamstring injuries occur?
    • How and when do hamstring injuries occur?
    • Which fitness equipment do you use to exercise?
    About

    ELITETRACK is one of the longest standing sport training & conditioning sites on the web. We feature over 250 articles and 1000s of blog posts from some of the most knowledgeable and experienced track & field coaches on the web.

    Recent Posts
    • Evidence Based Recovery for Peak Performance
    • Dealing With Chronic Back Pain: 4 Ways To Cope
    • Effective Strategies to Lose Fat
    • What You Should be Doing on Your Rest Days
    • Enjoying Sports into Retirement
    Forum Activity
    • rudeboy on ?Where I can start in multievents trainig?
    • Pablo25 on How and when do hamstring injuries occur?
    • Josh Hurlebaus on Josh Hurlebaus Masters Training Log
    • Josh Hurlebaus on Josh Hurlebaus Masters Training Log
    • Josh Hurlebaus on Josh Hurlebaus Masters Training Log
    ELITETRACK by Human Performance Consulting, LLC. All Rights Reserved. 2015.
    ELITETRACK by Human Performance Consulting, LLC. All Rights Reserved. 2021.

    Type above and press Enter to search. Press Esc to cancel.