Alterations in Running Economy and Mechanics After Maximal Cycling in Triathletes: Influence of Performance Level

Abstract

The effects of the triathlon performance level on the metabolic and mechanical alterations in running after an exhaustive cycling exercise were studied. Eight elite and 18 middle-level triathletes completed two 7 min runs on a treadmill at a velocity corresponding to that sustained during a triathlon before and after maximal cycling exercise. Energy cost of running was quantified during the last minute of each run from the net oxygen uptake. External mechanical cost was quantified during the last minute of each run from displacements of the centre of mass using a kinematic arm. The effect of cycling on the running energy cost differed when comparing the elite (from 4.01+/-0.46 to 3.86+/-0.34J x kg(-1) x m(-1)) and the middle-level triathletes (from 3.67+/-0.37 to 3.76+/-0.39 x kg(-1) x m(-1) (P<0.01). The effect of cycling on the respiratory muscle O2 was more important (P<0.05) for the middle-level (from 120.1+/-27.2 to 166.4+/-47.8 ml x min(-1)) than for elite triathletes (from 124.5 +/- 24.5 to 143.7 +/- 28.9 ml x min(-1)). A tendency to a decrease of the mechanical cost and of the vertical displacement of the centre of mass during the braking phase was observed for the elite triathletes, suggesting a better leg stiffness regulation than for their less successful counterparts.

Trends in Triathlon Performance: Effects of Sex and Age

“…[8,9] Triathlon performance has been studied from numerous perspectives by a number of research groups over approximately the same period that the sport has grown. Research has investigated physiological [1,10,11,12,13,14] , biomechanical [15,16,17] , training [16,18,19,20] , nutritional [21] or medical [22] aspects of triathlon performance. Although Ironman triathlon is a relatively new ultra-endurance event, recently elite Ironman triathletes appear to have reached their performance limits [2,23] as has been observed in more traditional sports such as marathon running where performance times have plateaued.…”

Características fisiológicas e biomecânicas na corrida do triatlo: uma revisão narrativa

“…18,28,29 Para explicar este aumento no VO 2 , alguns autores atribuem, em parte, à depleção do glicogênio durante os 40 km de ciclismo, concomitante com a alteração na utilização de substrato, no qual há uma predominância na mobilização para oxidação de gordura. 18 Por outro lado, acredita-se que este aumento tem relação parcial com a desidratação 11,12,14 atribuindo com a hemoconcentração, diminuição do volume sistó-lico, aumento na temperatura retal após o ciclismo 28 e a perda de peso corporal durante a corrida. 28,29 Contudo a concentração de lactato não teve alteração na condição de corrida precedida de ciclismo.…”

“…14 2-Desidratação; 3,11,12 3-Diminuição da atividade pulmonar; 11,12,14 4-Aumento do VO 2 na corrida do triatlo e alterações na eficiência ventilatória; 11,14,18,24 5-Elevada lactacidemia. 9 Portanto é importante destacar que as alterações citadas acima, comumente, podem ter repercussão em ajustes cinemáticos, metabólicos e neuromusculares da corrida no triatlo.…”

“…Os efeitos cumulativos das modalidades que antecede a corrida são responsáveis pela desidratação, 3,11,12 diminuição da atividade pulmonar, 11,12,14 diminuição de glicogênio muscular 3 e aumento da percentual do VO 2 máximo, porém, ainda é possível perceber que existem lacunas teóricas e práticas a esse respeito, como as diferentes adaptações relacionadas ao nível de treinamento, respostas agudas e crônicas da corrida após o ciclismo. Sendo assim, uma revisão sobre estes aspectos auxilia na compreensão da mecânica e energética da corrida de triatletas, contribuindo para a construção do treinamento mais específico para a modalidade.…”

Physiological requirements in triathlon

“…It has also been reported that the extent of any change in EC subsequent to an exhaustive cycling bout is influenced by athlete performance level, event distance, gender, and age. The effect of a fatiguing cycling bout on the subsequent running energy cost was different between elite (-3.7 ± 4.8%, when compared to an isolated run) and middle-level (2.3 ± 4.6%) triathletes (Millet, Millet, Hofmann, Candau, 2000). Elite LD triathletes had slightly (but not significantly) lower EC than OD triathletes (163.8 vs. 172.9 and 163.0 vs. 177.4 ml·kg -1 ·km -1 during an isolated and a 'triathlon' run, respectively) (Millet, Dreano, Bentley, 2003).…”