I know the issue of fatigue has been discussed a lot on here already, but could somebody break down some or just give an overview of some of the current theories of fatigue, especialy in relation to exercise?
Just an overview, maybe a few credible references. Not really looking for personal opinion or personal experiences or a debate about cns fatigue, just some references regarding the differening current thoughts on fatigue. Thanks.
This is probably not what you’re after, but I just read an article suggesting that fatigue in sprints is not caused by metabolic factors, but by the amount of time the muscle is contracted for. I am not really sure whether or not this is referring to CNS fatigue. I read this in The Coach Volume 38, a British athletics journal. I believe the author of the article at least reads this forum, but I am not sure of his identity.
Cytokine hypothesis of overtraining: a physiological adaptation to excessive stress?
BASIC SCIENCES
Medicine & Science in Sports & Exercise. 32(2):317, February 2000.
SMITH, LUCILLE LAKIER
Abstract:
SMITH, L. L. Cytokine hypothesis of overtraining: a physiological adaptation to excessive stress? Med. Sci. Sports Exerc., Vol. 32, No. 2, pp. 317-331, 2000. Overtraining syndrome (OTS) is a condition wherein an athlete is training excessively, yet performance deteriorates. This is usually accompanied by mood/behavior changes and a variety of biochemical and physiological alterations. Presently, there is no global hypothesis to account for OTS. The present paper will attempt to provide a unifying paradigm that will integrate previous research under the rubric of the cytokine hypothesis of overtraining. It is argued that high volume/intensity training, with insufficient rest, will produce muscle and/or skeletal and/or joint trauma. Circulating monocytes are then activated by injury-related cytokines, and in turn produce large quantities of proinflammatory IL-1[beta], and/or IL-6, and/or TNF-[alpha], producing systemic inflammation. Elevated circulating cytokines then co-ordinate the whole-body response by: a) communicating with the CNS and inducing a set of behaviors referred to as “sickness” behavior, which involves mood and behavior changes that support resolution of systemic inflammation; b) adjusting liver function, to support the up-regulation of gluconeogenesis, as well as de novo synthesis of acute phase proteins, and a concomitant hypercatabolic state; and c) impacting on immune function. Theoretically, OTS is viewed as the third stage of Selye’s general adaptation syndrome, with the focus being on recovery/survival, and not adaptation, and is deemed to be “protective,” occurring in response to excessive physical/physiological stress. Recommendations are made for potential markers of OTS, based on a systemic inflammatory condition.
©2000The American College of Sports Medicine
This is referring more to long term, negative(different from overreaching) overtraining rather than the short term CNS fatigue Charlie refers to with the 48 hr rule and I am not sure they are caused by the same thing(sprinters also probably have to deal with a significant amount of SEC fatigue among other possible contributors to short term fatigue) but it is still an interesting theory on why there seems to be a point of no return if someone does much more volume than they are accustomed to for a long period of time.
Charlie’s ‘48 hour rule’ applies to CNS recovery or rebooting. What if the CNS can maintain high output for more than one training session in a row possibly spanning 2-3 days (a la big meets)?
If you’re trying to do more total speed work, can you do hi-hi-low-hi-hi-low gaining an extra hi session per week? You might have to play with the organization of weights to help this work better but I think it’s still an option.
yeah there are definately different variations as far as how you can assign and manipulate volume/frequency throughout both the week and training year. As long as you monitor your training carefully and watch out for bad signs(excessive tightness, heavy feet,ect.) I would think there are different ways to reach the same end goal.