Document Detail


Physiological changes associated with the pre-event taper in athletes.
MedLine Citation:
PMID:  15487904     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Some of the physiological changes associated with the taper and their relationship with athletic performance are now known. Since the 1980s a number of studies have examined various physiological responses associated with the cardiorespiratory, metabolic, hormonal, neuromuscular and immunological systems during the pre-event taper across a number of sports. Changes in the cardiorespiratory system may include an increase in maximal oxygen uptake, but this is not a necessary prerequisite for taper-induced gains in performance. Oxygen uptake at a given submaximal exercise intensity can decrease during the taper, but this response is more likely to occur in less-skilled athletes. Resting, maximal and submaximal heart rates do not change, unless athletes show clear signs of overreaching before the taper. Blood pressure, cardiac dimensions and ventilatory function are generally stable, but submaximal ventilation may decrease. Possible haematological changes include increased blood and red cell volume, haemoglobin, haematocrit, reticulocytes and haptoglobin, and decreased red cell distribution width. These changes in the taper suggest a positive balance between haemolysis and erythropoiesis, likely to contribute to performance gains. Metabolic changes during the taper include: a reduced daily energy expenditure; slightly reduced or stable respiratory exchange ratio; increased peak blood lactate concentration; and decreased or unchanged blood lactate at submaximal intensities. Blood ammonia concentrations show inconsistent trends, muscle glycogen concentration increases progressively and calcium retention mechanisms seem to be triggered during the taper. Reduced blood creatine kinase concentrations suggest recovery from training stress and muscle damage, but other biochemical markers of training stress and performance capacity are largely unaffected by the taper. Hormonal markers such as testosterone, cortisol, testosterone : cortisol ratio, 24-hour urinary cortisol : cortisone ratio, plasma and urinary catecholamines, growth hormone and insulin-like growth factor-1 are sometimes affected and changes can correlate with changes in an athlete's performance capacity. From a neuromuscular perspective, the taper usually results in markedly increased muscular strength and power, often associated with performance gains at the muscular and whole body level. Oxidative enzyme activities can increase, along with positive changes in single muscle fibre size, metabolic properties and contractile properties. Limited research on the influence of the taper on athletes' immune status indicates that small changes in immune cells, immunoglobulins and cytokines are unlikely to compromise overall immunological protection. The pre-event taper may also be characterised by psychological changes in the athlete, including a reduction in total mood disturbance and somatic complaints, improved somatic relaxation and self-assessed physical conditioning scores, reduced perception of effort and improved quality of sleep. These changes are often associated with improved post-taper performances. Mathematical models indicate that the physiological changes associated with the taper are the result of a restoration of previously impaired physiological capacities (fatigue and adaptation model), and the capacity to tolerate training and respond effectively to training undertaken during the taper (variable dose-response model). Finally, it is important to note that some or all of the described physiological and psychological changes associated with the taper occur simultaneously, which underpins the integrative nature of relationships between these changes and performance enhancement.
Authors:
Iñigo Mujika; Sabino Padilla; David Pyne; Thierry Busso
Related Documents :
15231224 - Nutrition for the pediatric athlete.
12831664 - Upper respiratory tract infections: who plays, who sits?
16558254 - Upper extremity proprioceptive training.
12119864 - Special issues and concerns for the high school- and college-aged athletes.
21042574 - Myogenin regulates exercise capacity and skeletal muscle metabolism in the adult mouse.
2843314 - Effects of opioid antagonism on the haemodynamic and hormonal responses to exercise.
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Sports medicine (Auckland, N.Z.)     Volume:  34     ISSN:  0112-1642     ISO Abbreviation:  Sports Med     Publication Date:  2004  
Date Detail:
Created Date:  2004-10-18     Completed Date:  2005-04-18     Revised Date:  2005-11-16    
Medline Journal Info:
Nlm Unique ID:  8412297     Medline TA:  Sports Med     Country:  New Zealand    
Other Details:
Languages:  eng     Pagination:  891-927     Citation Subset:  IM    
Affiliation:
Department of Research and Development, Medical Services, Athletic Club of Bilbao, Basque Country, Spain. imujika@grn.es
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology*
Blood Pressure / physiology
Energy Metabolism / physiology
Exercise / physiology
Heart Rate / physiology
Hormones / blood
Humans
Immune System / physiology
Lactic Acid / blood,  metabolism
Models, Theoretical
Oxygen Consumption / physiology
Professional Competence*
Sports / physiology*
Chemical
Reg. No./Substance:
0/Hormones; 50-21-5/Lactic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Caffeine and ephedrine: physiological, metabolic and performance-enhancing effects.
Next Document:  Soccer injuries: a review on incidence and prevention.