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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!

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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

Periodização do treinamento

Porque não devo treinar a mesma coisa todos os dias? Porque só posso treinar 1 hora e não 5 horas?

 A resposta para essa pergunta está ligada diretamente ao sistema imune e a capacidade de se adaptar do atleta as carags de estresse. Primeiro devemos entender que a maioria dos efeitos posistivos do exercício ocorre no período de recuperação das cargas de treino, que podem corresponder a uma sessão ou até várias sessões, denominadas de ciclos. O menor ciclo de treinamento é o microciclo, mas em esportes com futebol e algumas modalidades há os chamodos submicrocliclos que possibilitam a excelêcia na sequência dos jogos de uma competição.

 A intensidade e o volume afetam diretamente a resposta do sistema imune. Atividade física com intensidade moderada (<60% VO2max) esta relacionado ao aumento da resposta dos mecanismos do sistema imune. Contudo, exercícios prolongados (>65% VO2max) ou o treino excessivo parecem estar relacionado a redução da resposta dos mecanismos do sistema imune. 
 O Exercício intenso provoca um aumento na concentração de leucócitos na circulação. Pedersen e Bruunsgaard (1995) relatam que a imunossupressão observada é evidente quando o exer. é intenso e de longa duração (60 min ou mais). Robson e col. (1982) compararam o efeito do exer. a 80% VO2máx (durante 1 hora) com um exer. a 55%VO2max (durante 3 horas) em indivíduos ativos. Verificaram, contudo, que durante e após o esforço há um aumento similar na contagem dos neutrófilos polimorfonucleares em ambas   intensidades. 
 As alterações nas funções dos neutrófilos parecem ser dependentes da intensidade e  da duração do exercício. A reposta a diferentes cargas podem refletir um estado de stress ou imunossupressão e ser um indicativo de overtraining. 
 Davis e col. Verificaram que o exercício extenuante de longa duração (2,5-3,5 h) pode provocar diminuição na atividade anti-viral de macrófagos alveolares e aumentar a susceptibilidade de infecções em ratos. 
 A sobrecarga sobre os linfócitos mostram que durante o exercício é verificado um aumento de linfócitos em cerca de 50% a 100% em relação ao valor basal. No período de recuperação, 30 minutos após o exercício, a contagem de linfócitos diminui de 30% a 50% abaixo dos níveis pré-exercício, permanecendo assim durante 3 a 6 horas. Também os exercícios intensos de longa duração induzem a apoptose de linfócitosdevido ao aumento do cortisol, que podem estar realcionados à imunosupressão. Os exercícios intensos de curta duração (>100% VO2máx) ou intensos de longa duração (=80% VO2max) > 60 min, provocam: redução da saturação da hemoglobina arterial; aumento na temperatura corporal; lesões musculares; hipoxemia e as lesões teciduais associadas. Assim, as respostas metabólicas induzem a alterações na resposta imune com libertação de citocinas pró-inflamatórias incluindo a IL-1, a IL-6 e o TNFa.

 Assim, podemos afirmar que o treinamento esta relacionado a aplicação corretas das cargas de treino e o conhecimento específico de como controlar os mecanismos de estresse que induzem a adaptação.

 

http://triathlete-europe.competitor.com/2012/03/28/increase-your-swim-speed-kick-it/

Tamanho do pedivela e a performance no mountain bike

Original Article
Influence of crank length on cycle ergometry performance of well-trained female cross-country mountain bike athletes

Paul William Macdermid and Andrew M. Edwards Abstract
The aim of this study was to determine the differential effects of three commonly used crank lengths (170, 172.5 and 175 mm) on performance measures relevant to female cross-country mountain bike athletes (n = 7) of similar stature. All trials were performed in a single blind and balanced order with a 5- to 7-day period between trials. Both saddle height and fore-aft position to pedal axle distance at a crank angle of 90° was controlled across all trials. The laboratory tests comprised a supra-maximal (peak power-cadence); an isokinetic (50 rpm) test; and a maximal test of aerobic capacity. The time to reach supra-maximal peak power was significantly (P < 0.05) shorter in the 170 mm (2.57 ± 0.79 s) condition compared to 175 mm (3.29 ± 0.76 s). This effect represented a mean performance advantage of 27.8% for 170 mm compared to 175 mm. There was no further inter-condition differences between performance outcome measurements derived for the isokinetic (50 rpm) maximum power output, isokinetic (50 rpm) mean power output or indices of endurance performance. The decreased time to peak power with the greater rate of power development in the 170 mm condition suggests a race advantage may be achieved using a shorter crank length than commonly observed. Additionally, there was no impediment to either power output produced at low cadences or indices of endurance performance using the shorter crank length and the advantage of being able to respond quickly to a change in terrain could be of strategic importance to elite athletes.

Keywords Propulsion - Cranks - Bike position - Levers

European Journal of Applied Physiology - SpringerLink

www.springerlink.com