More about the contradictory effects

Discussion in 'Performance Research' started by abanger, Nov 23, 2009.

  1. abanger

    abanger Member

    More about the contradictory effects of strength training + cardio workout
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    (Borge Fagerli @ Aug. 20 2008,4:01)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">As I was in for in section 2 of the article about dining Kick the diet, and as I said a few times here - I prefer to separate the stimulus strength from stimulus cardio / endurance training as possible, as there are conflicting signals may cancel each other out. This applies particularly to AMPK, the energy sensor signal increases after endurance training and that directly reduces protein synthesis (muscle growth and recovery). AMPK is also something we try to reduce using Myo-reps when we train the force, which is another good reason to not train for a high amount when you will get stronger and build muscle mass, and to ensure that gjenoppfyller glycogen stores after exercise with carbohydrate.

    The recommendation is therefore to train cardio and strength training separated by at least 4 hours, for example, morning + afternoon or evening, or on separate days. Will focus on endurance training strength training should be cut down to something like twice a week, will focus on strength training and muscle building cardio should be limited to something like 20-30 minutes 3-4 times a week. Will train both lilke much one must also accept that there is likely to give poorer results overall. Jack of all trades, master of none.


    Excerpts from an article I have based this on, and that David Hookes pointed out in a discussion of the Guerrilla Cardio on Iform:



    Concurrent Strength and Endurance Training: From Molecules to Man. Medicine &amp; Science in Sports &amp; Exercise. 38 (11) :1965-1970, November 2006

    &quot;Strength and endurance training produce widely diversified adaptations, with little overlap between them. Strength training typically results in increases in muscle mass and muscle strength. In contrast, endurance training induces increases in maximal oxygen uptake and metabolic adaptations that lead to an increased exercise capacity . In many sports, a combination of strength and endurance training is required to improve performance, but in some situations when strength and endurance training are performed simultaneously, a potential interference in strength development takes place, making such a combination seemingly incompatible. The phenomenon of concurrent training, or simultaneously training for strength and endurance, was first described in the scientific literature in 1980 by Robert C. Hickson, and Although work that followed provided evidence for and against it, the interference effect seems to hold true in specific situations. The the molecular level, there seems to be an explanation for the interference of strength development during concurrent training, it is now clear that different forms of exercise induce antagonistic intracellular signaling mechanisms that, in turn, could have a negative impact on the muscle's adaptive response to this particular form of training. That is, activation of AMPK by endurance exercise may inhibit signaling to the protein-synthesis machinery by inhibiting the activity of mTOR and its downstream targets. The purpose of this review is two briefly describe the problem of concurrent strength and endurance training and two examine new data highlighting potential molecular mechanisms that may help explain the inhibition of strength development when strength and endurance training are performed simultaneously. &quot;

    &quot;Acute endurance exercise bouts have generally been found two reduce the total protein synthesis rates of mixed skeletal muscles during the exercise. This depression is transient and can lead to a temporary decrease in protein synthesis within several hours after exercise (5,12,29) . Overlap endurance exercise bouts with resistance exercise may result in impaired adaptive responses in protein synthesis and, therefore, a decrease in strength-related performance, in part, due to the suboptimal or lack of increase in muscle fiber cross-sectional areas (22 ). When performed several times a week, such combination training may be sufficient two disrupt the protein-synthesis mechanisms involved with the normal adaptation to the individual bouts of strength exercise, thus altering the long-term adaptations two training and resulting in impaired muscle - dependent strength gains. Another possibility, Although hypothetical, is that the adaptive protein synthesis resulting from either form of exercise may create some sort of cellular incompatibility in which the muscle cell needs two decide whether to grow or manage the synthesis of its metabolic machinery. &quot;</div>
     
  2. Lol

    Lol Super Moderator Staff Member

    J Strength Cond Res. 2008 Jul;22(4):1037-45.

    Effect of concurrent endurance and circuit resistance training sequence on muscular strength and power development.

    Chtara M, Chaouachi A, Levin GT, Chaouachi M, Chamari K, Amri M, Laursen PB.

    Institute of Sport and Physical Education, Ksar Said, Tunis, Tunisia.

    The purpose of this study was to examine the influence of the sequence order of high-intensity endurance training and circuit training on changes in muscular strength and anaerobic power. Forty-eight physical education students (ages, 21.4 +/- 1.3 years) were assigned to 1 of 5 groups: no training controls (C, n = 9), endurance training (E, n = 10), circuit training (S, n = 9), endurance before circuit training in the same session, (E+S, n = 10), and circuit before endurance training in the same session (S+E, n = 10). Subjects performed 2 sessions per week for 12 weeks. Resistance-type circuit training targeted strength endurance (weeks 1-6) and explosive strength and power (weeks 7-12). Endurance training sessions included 5 repetitions run at the velocity associated with Vo2max (Vo2max) for a duration equal to 50% of the time to exhaustion at Vo2max; recovery was for an equal period at 60% Vo2max. Maximal strength in the half squat, strength endurance in the 1-leg half squat and hip extension, and explosive strength and power in a 5-jump test and countermovement jump were measured pre- and post-testing. No significant differences were shown following training between the S+E and E+S groups for all exercise tests. However, both S+E and E+S groups improved less than the S group in 1 repetition maximum (p &lt; 0.01), right and left 1-leg half squat (p &lt; 0.02), 5-jump test (p &lt; 0.01), peak jumping force (p &lt; 0.05), peak jumping power (p &lt; 0.02), and peak jumping height (p &lt; 0.05). The intrasession sequence did not influence the adaptive response of muscular strength and explosive strength and power. Circuit training alone induced strength and power improvements that were significantly greater than when resistance and endurance training were combined, irrespective of the intrasession sequencing.
     
  3. Lol

    Lol Super Moderator Staff Member

    J Appl Physiol. 2009 Jan 22. [Epub ahead of print]

    Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle.

    Coffey VG, Pilegaard H, Garnham AP, O'Brien BJ, Hawley JA.

    RMIT University.

    We examined acute molecular responses in skeletal muscle to divergent exercise stimuli by combining consecutive bouts of resistance and endurance exercise. Eight men (22.9 +/- 6.3 yr, body mass 73.2 +/- 4.5 kg, VO2peak 54.0 +/- 5.7 mL(.)kg(-1)(.)min(-1)) were randomly assigned to complete trials consisting of either resistance exercise (8 x 5 leg extension, 80% 1RM) followed by a bout of endurance exercise (30 min cycling, 70% VO2peak), or vice-versa. Muscle biopsies were obtained from the vastus lateralis at rest, 15 min after each exercise bout and following 3 h of passive recovery to determine early signaling and mRNA responses. Phosphorylation of Akt and Akt1 (ser473) were elevated 15 min after resistance exercise but not cycling, with the greatest increase observed when resistance exercise followed cycling (~55%, P&lt;0.01). TSC2-mTOR-S6K phosphorylation 15 min following each bout of exercise was similar regardless of exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (-42%) while MuRF mRNA was elevated when cycling was undertaken after resistance exercise (~52%, P&lt;0.05). The HKII mRNA level was higher following resistance-cycling (~45%, P&lt;0.05) than cycling-resistance exercise, while modest increases in PGC-1 mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates &quot;adaptation interference&quot;.
     
  4. Lol

    Lol Super Moderator Staff Member

    Appl Physiol Nutr Metab. 2009 Jun;34(3):355-61.

    Molecular responses to strength and endurance training: Are they incompatible?

    Hawley JA.

    Exercise Metabolism Group, School of Medical Sciences, RMIT University, Bundoora, Australia (e-mail: [email protected]).

    Simultaneously training for both strength and endurance results in a compromised adaptation, compared with training for either exercise mode alone. This has been variously described as the concurrent training effect or the interference effect. It now appears that the genetic and molecular mechanisms of adaptation induced by resistance- and endurance-based training are distinct, with each mode of exercise activating and (or) repressing specific subsets of genes and cellular signalling pathways. This brief review will summarize our current understanding of the molecular responses to strength and endurance training, and will examine the molecular evidence for an interference effect when concurrent training is undertaken. A better understanding of the activation and interaction of the molecular pathways in response to these different modes of exercise will permit sport scientists to develop improved training programs capable of maximizing both strength and endurance.
     

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