Entrainement d endurence/ stamina Training
🔞 TOUTES LES INFORMATIONS CLIQUEZ ICI 👈🏻👈🏻👈🏻
Entrainement d endurence/ stamina Training
Dein Browser wird nicht mehr unterstützt. Aktualisiere ihn, um YouTube und unsere neuesten Funktionen optimal nutzen zu können. Weitere Informationen
Wolters Kluwer Health
may email you for journal alerts and information, but is committed
to maintaining your privacy and will not share your personal information without
your express consent. For more information, please refer to our Privacy Policy.
Subscribe
Register
Login
Separate multiple e-mails with a (;).
Thought you might appreciate this item(s) I saw in The Journal of Strength & Conditioning Research.
Some error has occurred while processing your request. Please try after some time.
Journal of Strength and Conditioning Research:
June 2012 - Volume 26 - Issue 6 - p 1724-1729
Training variables affecting conversion from type I to type II muscle fibers. This graphically depicts the effects of manipulating intensity, volume, and contractile velocity of all training types (endurance and resistance training) on muscle fiber type conversions.
Cited Here |
View Full Text | PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
View Full Text | PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
View Full Text | PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
View Full Text | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
View Full Text | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
Cited Here |
PubMed | CrossRef
The Journal of Strength & Conditioning Research26(6):1724-1729, June 2012.
Separate multiple e-mails with a (;).
Thought you might appreciate this item(s) I saw in The Journal of Strength & Conditioning Research.
Some error has occurred while processing your request. Please try after some time.
Separate multiple e-mails with a (;).
Thought you might appreciate this item(s) I saw in The Journal of Strength & Conditioning Research.
Some error has occurred while processing your request. Please try after some time.
View full article metrics
including social shares, article views and publishing history
Articles in PubMed by Jacob M. Wilson
This article in PubMed
Articles in Google Scholar by Jacob M. Wilson
Other articles in this journal by Jacob M. Wilson
Data is temporarily unavailable. Please try again soon.
Strength and Hypertrophy Adaptations Between Low- vs. High-Load Resistance Training: A Systematic Review and Meta-analysis
Periodization and Block Periodization in Sports: Emphasis on Strength-Power Training—A Provocative and Challenging Narrative
The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training
Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men
Concurrent Training: A Meta-Analysis Examining Interference of Aerobic and Resistance Exercises
Get new journal Tables of Contents sent right to your email inbox
Get New Issue Alerts
Browse Journal Content
Most Popular
For Authors
About the Journal
Past Issues
Current Issue
Register on the website
Subscribe
Get eTOC Alerts
For Journal Authors
Submit an article
How to publish with us
800-638-3030
(within USA)
301-223-2300
(international)
Your message has been successfully sent to your colleague.
Wilson, Jacob M.; Loenneke, Jeremy P.; Jo, Edward; Wilson, Gabriel J.; Zourdos, Michael C.; Kim, Jeong-Su
1 Department of Health Sciences and Human Performance, The University of Tampa, Tampa, Florida
2 Department of Health and Exercise Science, The University of Oklahoma, Norman, Oklahoma
3 Department of Nutrition, Food, and Exercise Sciences, The Florida State University, Tallahassee, Florida
4 Department of Nutritional Sciences, University of Illinois, Champaign-Urbana, Illinois
Address correspondence to Jacob M. Wilson, jmwilson@ut.edu .
Wilson, JM, Loenneke, JP, Jo, E, Wilson, GJ, Zourdos, MC, and Kim, J.-S. The effects of endurance, strength, and power training on muscle fiber type shifting. J Strength Cond Res 26(6): 1724–1729, 2012—Muscle fibers are generally fractionated into type I, IIA, and IIX fibers. Type I fibers specialize in long duration contractile activities and are found in abundance in elite endurance athletes. Conversely type IIA and IIX fibers facilitate short-duration anaerobic activities and are proportionally higher in elite strength and power athletes. A central area of interest concerns the capacity of training to increase or decrease fiber types to enhance high-performance activities. Although interconversions between type IIA and IIX are well recognized in the literature, there are conflicting studies regarding the capacity of type I and II fibers to interconvert. Therefore, the purpose of this article is to analyze the effects of various forms of exercise on type I and type II interconversions. Possible variables that may increase type II fibers and decrease type I fibers are discussed, and these include high velocity isokinetic contractions; ballistic movements such as bench press throws and sprints. Conversely, a shift from type II to type I fibers may occur under longer duration, higher volume endurance type events. Special care is taken to provide practical applications for both the scientist and the athlete.
A myriad of experimental research has centered on the role that skeletal muscle fiber makeup plays in determining performance ( 1,9,16,17,47 ), and results of the research collected from our group have clearly demonstrated the ability of skeletal muscle to undergo cellular changes in response to resistance exercise ( 7,27–29,33,36 ). Muscle fibers are generally fractionated into slow twitch I (slow-oxidative), fast twitch IIA (fast-oxidative glycolytic), and fast twitch IIX (fast glycolytic) types. Several studies have analyzed muscle fiber types of elite athletes across various sports ( 1,9,49 ). In a classic study, Costill et al. ( 13 ) found that untrained individuals had a 50/50 ratio of fast (type IIA and IIX) to slow twitch (type I) fibers. However, in the athletic population, long and middle distance runners had 60–70% slow twitch fibers, whereas sprinters demonstrated an 80% fast twitch fiber makeup. Moreover, elite weight and power lifters have been found to have a significantly greater fast twitch fiber makeup (60%) than endurance athletes (40%) have ( 49 ). Other studies have indicated that athletes in sports requiring the greatest aerobic and endurance capacities have slow twitch fiber percentages as high as 90–95%, whereas athletes in sports requiring greater anaerobic capacities, strength, and power (e.g., weight lifting and sprinting) have fast twitch fibers ranging from 60 to 80% ( 1,9,17 ).
By examining the attributes of different fiber types, it becomes evident as to why there is such variation in their distribution among groups of athletes. To illustrate, type I fibers have been observed to have both greater mitochondria volume densities and capillary-fiber contact length when compared with those of type II fibers ( 45 ). In addition, mitochondria volume density was highly correlated ( r = 0.99) with O 2 diffusion coefficients across 3 different muscle groups (retractor, sartorius, and soleus) suggesting greater aerobic capacity in type I fibers ( 45 ). More recent data from single fiber studies demonstrate that type IIX and IIA fibers have 10 and 6 times greater peak power, respectively, than type I fibers do ( 49 ). Moreover, type IIX and IIA fibers have demonstrated 4.4 and 3 times greater contractile velocity than type I fibers have demonstrated, respectively ( 32 ). Although no differences were found in specific force (force/cross sectional area [CSA]), absolute force was greater in type II fibers because of a 39 and 26% greater CSA in IIX and IIA than in type I fibers, respectively ( 32 ). Type II fibers have a greater capacity for exercise-induced hypertrophy ( 26,40 ) and hydrolyze adenosine triphosphate (ATP) 2–3 times faster than type I fibers do ( 46 ). Finally, isolated single fibers belonging to the same type demonstrate identical contractile properties regardless of their muscle group origin ( 46 ).
The contribution of slow twitch muscle fibers to endurance performance was investigated by Bergh et al. ( 9 ) who found a direct relationship between V[Combining Dot Above]O 2 max and the percentage of slow twitch fibers ( r = 0.67) in 53 weightlifters and endurance athletes. Moreover, a positive relationship has been demonstrated ( r = 0.52–0.55) between slow twitch fiber composition in well-trained runners and performance in 1-, 2-, and 6-mile runs ( 16 ). In anaerobic activities, strong correlations are present between the percent of IIA fibers and 1 repetition maximum (1RM) snatch performance ( r = 0.94), static vertical jump height ( r = 0.79) and power ( r = 0.75), and countermovement vertical jump power ( r = 0.83) in national caliber Olympic weightlifters ( 17 ). Similarly, research studies have demonstrated moderate ( r = 0.61) to high correlations ( r = 0.93) between myosin heavy chain (MHC) II percentage in the quadriceps muscle and knee extension strength at medium and high velocities, respectively ( 1 ). In addition, relationships exist between type II fiber distribution in the triceps brachii muscle with both normal ( r = 0.7) and seated shot put (range r = 0.6–0.79) and bench press performances ( r = 0.86) ( 47 ).
Although the above data suggest a strong role of muscle fiber makeup and performance, the question begets itself: “Are athletes endowed with greater percentages of fast or slow twitch fibers, or can correlations between fiber types and performance be accounted for by training?” The purpose of the following article is to analyze the contribution of training to muscle fiber type expression. Concepts will be discussed from both practical and future research-oriented perspectives.
Research from our laboratory and from others has clearly shown that training can shift type IIX fibers to IIA and vice versa ( 6,26,41 ). Therefore, the argument centers on whether training can change fast twitch fibers into slow twitch fibers and vice versa.
The first study to examine the effects of exercise on fiber type plasticity in human skeletal muscle was conducted by Gollnick et al. ( 18 ) using myosin ATPase staining. Six untrained participants exercised 1 h·d −1 , 4 d·wk −1 , for 5 months, at 85–90% of V[Combining Dot Above]O 2 max. The results found no significant difference in pretest to posttest measurements (32% slow twitch, to 36% slow twitch post). The authors suggested that the small sample size might have prevented them from reaching significance. It is interesting to note from this study that the 2 participants with the largest percentage of slow twitch fiber types increased their percentage of slow twitch fibers by 9% during the study (23–32%).
Following this pioneer experiment ( 18 ), several investigators ( 2,11,21,34 ) have obtained similar results when examining muscle fiber type plasticity with various populations and differing protocols. For example, neither 8 weeks of jump squats using either 30 or 80% of subjects' 1RM ( 34 ) nor 4 d·wk −1 of 3 sets of 3 second maximal sprints ( 21 ) resulted in an interconversion between fast and slow muscle fiber types in the quadriceps ( 21,34 ) or the soleus ( 21 ). Similarly, 6, 9 ( 11 ), or 19 weeks of resistance training ( 2 ) failed to elicit interfiber conversions. Collectively, these results oppose the contention that exercise induces fiber type shifting from slow to fast twitch and vice versa. However, additional studies suggest that by using certain training programs, exercise-induced muscle fiber type conversions may be possible.
One particular variable of interest concerns high velocity contractions. To illustrate this, Liu et al. ( 31 ) investigated the effects of training on MHC isoform
Deux salopes chinoises dans un bon trio
Salope brune se prend trois queues
Deux teens jumelles russes nues avec une copine