Características fisiológicas do triathlon

   A demanda fisiológica da prática seqüenciada das três modalidades é única” (SLEIVERT; ROWLANDS, 2000, p. 4). O atleta de triathlon de alta performance deve possuir características próprias para a modalidade (ITU, 2001).  A primeira determinante do sucesso no triatlo é a capacidade de sustentar um alto percentual de despediu energético por um prolongado período de tempo” (O’TOLLE; DOUGLAS, 1995, p. 251).  

   O consumo máximo de oxigênio (VO2) é um fator determinante na performance (LAURSEN, P.B. e RHODES, E. C., 2001).  Quando as distâncias do triathlon aumentam a relação entre o VO2max  e o tempo de performance diminuem (O’TOOLE, M. L. e DOUGLAS, P. S. 1995). O VO2max ou a PMS, em teste no cicloergômetro, mostra alta correlação com o tempo nos 40km de ciclismo e o tempo completo da prova (r= -0,91 e -0,86, respectivamente) SCHABORT, E. J e col. (2000).  Não há relação entre LA e o IRONMAN. Não existe diferença significativa entre o VO2max e os limiares ventilatórios mensurado na esteira e cicloergômetros em triatletas de elite.

   A posição abaixada no ciclismo gera diminuição da capacidade de difusão pulmonar pela diminuição da capacidade inspiratória máxima, provocando um aumento da taxa de trabalho do diafragma que gerou um quadro de edema. A capacidade inspiratória máxima tende a aumentar durante a corrida após o ciclismo revertendo o quadro edemático.
  
Dados importantes mostram:
  1. Aumento na VE/VO2 no segmento corrida após o ciclismo.
  2. Diminuição da PaO2 e DLCO2 no segmento corrida após o ciclismo.
  3. Efeitos da transição C-R podem durar 8 minutos.
  4. O vacúo reduz em até 30% no gasto energético.
    1. Lactato no final da natação foi de 8,4 ± 0,5 mmol/L, com o uso do vácuo 4,0 ± 0,3 mmol/L.  
    2. Lactato no final do ciclismo os valores encontrados foram de 8,4 ±0,5 mmol/L, com o uso do vácuo 4,0 ± 0,3 mmol/L.
    3. Lactato no final da corrida mostrou uma concentração de 7,6 ±0,4 mmol/L, enquanto com o uso do vácuo a concentração de lactato no sangue ficou em torno de 4,1 ±0,7 mmol/L.
       
      Continua.
 

O professor de Educação Física e Atleta Geraldo Sena, da Prosports/MATreinamento, sobe ao pódio, mesmo após problemas na bike no percuros duríssimo do 7° Montanha Cup.

www.montanhasports.com.br/

Applied physiology of a triathlon.

Sports Med. 1989 Oct;8(4):201-25.

Applied physiology of a triathlon.

Source

Human Performance Laboratory, University of Tennessee, Memphis.

Abstract

The triathlon is an endurance contest in which contestants must compete in 3 consecutive events, usually swimming, cycling and running. Success in a triathlon depends upon the ability of the triathlete to perform each of the sequential events at optimal pace without creating fatigue that will hinder performance in the next event. The successful triathlete must, therefore, have highly developed oxygen transport and utilisation systems as well as the ability to efficiently produce a high energy output for prolonged periods without creating metabolic acidosis. Accordingly, mean VO2max values for groups of triathletes during treadmill running have been reported to range from 52.4 to 72 ml/kg/min in men; 58.7 to 65.9 ml/kg/min in women. VO2max values during cycle ergometry were 3 to 6% less than treadmill running values; tethered swimming maximums 13 to 18% less. Predictable and well-known adaptations occur in the cardiovascular systems of triathletes. Structural adaptations of the heart that have been documented in triathletes include increased left ventricular cavity size or wall thickness, or both. Morphological characteristics of the triathlete's heart appear to be unrelated to success in triathlon races. Following the acute stress of triathlon competition, alterations in both systolic and diastolic function have been observed. Heart muscle fatigue is the most likely reason for these changes, since there is a rapid return to normal with rest. Like the cardiovascular system, the musculoskeletal system responds to triathlon training. Peripheral adaptations occur that lead to increased muscle respiratory capacity and to modifications in substrate utilisation. The musculoskeletal system is the site of most injuries to triathletes, and non-traumatic overuse injuries account for 80 to 85% of the musculoskeletal injuries. Maintenance of fluid and electrolyte balance is of primary importance for the triathlete both in day-to-day training and during races. Water may be an adequate replacement fluid for short distance triathlons, but some combination of carbohydrate, electrolyte and fluid replacement is necessary for longer races. Although the physiological bases for success in a triathlon are not well understood at present, the ability to maintain minimal alterations in the homeostasis of cardiovascular, haemodynamic, thermal, metabolic, and musculoskeletal functions are of obvious importance.
PMID:
2692116
[PubMed - indexed for MEDLINE] 
 
http://www.ncbi.nlm.nih.gov/pubmed/2692116
 

Canal GoSwim o canal da natação na internet.

O canal goswim http://www.goswim.tv/ oferece ao seus visitantes ótimas dicas de natação, mostrando educativos, modelos de treino, técnicas dos nados, através de videos, artigos e fotos. O site ainda permite a discussão através de forum.

Bom nado!

http://www.goswim.tv/#

Mark Allen Boulder Triathlon Camp

Preparem os passaportes, a lenda do triathlon Mark Allen, na paraíso do treinamento para esportes de resistência, Boulder, Colorado (EUA), entre os dias 15-17 de julho de 2012, organiza um camp training. São 11 vagas disponíveis.
http://www.markallenonline.com/luismaocamp.aspx

Decrease of Endurance Performance During Olympic Triathlon

Decrease of Endurance Performance During Olympic Triathlon 
G. De Vito1, M. Bernardi1, E. Sproviero1, F. Figura2


Abstract
The present study was carried out in order to quantify the athlete's endurance impairment after two out of three sequential events of Olympic Triathlon (OT). Furthermore the significance of ventilatory threshold (Tvent) and peak of oxygen uptake (VO2peak) as triathlete's performance predictors was assessed. Tvent and VO2peak were measured in six male triathletes performing an incremental treadmill test a week before an ad hoc triathlon event. The same test was applied immediately after the first two segments of the triathlon (1.5 km swim, 32 km bike). VO2peak and Tvent measured during the latter test were reduced compared to the first test. VO2peak decreased from 69 to 64 ml · kg-1 · min1' and Tvent from 58 to 51 ml · kg-1 · min-1 (p<0,01), respectively. VO2peak and Tvent measured in the first test were well correlated (P<0.05) to both running and cycling times. The Tvent measured during the second test was related to the running time but with a higher significance (p < 0.01) than in the first test. The impairment in the endurance performance induced by the first two segments of OT is an important aspect to consider both in training and in race strategy. These results also provide evidence that VO2peak and Tvent are good predictors of triathlon performance at least in cycling and running events.

Key words

Olympic triathlon - ventilatory threshold - maximal oxygen uptake - endurance

https://www.thieme-connect.com/ejournals/abstract/sportsmed/doi/10.1055/s-2007-972958

Physiological predictors of short-course triathlon performance

Physiological predictors of short-course triathlon performance

SLEIVERT, GORDON G.; WENGER, HOWARD A.


Abstract

The purpose of this study was to investigate if selected physiological variables were related to triathlon performance. Eighteen male and seven female triathletes competed in a short-course triathlon (1 -km swim, 30-km cycle, 9-km run) and underwent physiological testing within 14 d. VO2max and ventilatory threshold (VT) were measured on a cycle ergometer, treadmill, and tethered swim apparatus. Leg flexion and extension strength were measured on a Cybex II isokinetic dynamometer. Multiple linear regression did not improve the prediction of triathlon performance over that provided by simple correlations, Swim performance was related to relative swim VO2max in both males (r = -0.48) and females (r = -0.93) as well as the resistance pulled at swim VT (r = -0.81) and absolute leg flexion strength (r = -0.77) in females. No physiological variables were significantly related to cycling time in either gender. Running time was related to relative VO2max (r = -0.88) in females and velocity at run VT in both females (r = -0.88) and males (r = -0.73). Relative swim VO2max, (r = -0.98), velocity at run VT (r = -0.89), and absolute leg flexion strength (r = -0.80) were related to overall performance in female triathletes. The only significant predictor of overall triathlon time for males was velocity at run VT (r = -0.78). It therefore appears that in short-course triathletes physiological variables in swimming and running are important to overall performance. Differences in sample size, group variability, and level of performance between males and females may account for the reported differences in the physiological predictors of performance between genders.
(C)1993The American College of Sports Medicine


http://journals.lww.com/acsm-msse/Abstract/1993/07000/Physiological_predictors_of_short_course_triathlon.17.aspx