Acute effect of uphill running: current scenario and future hypotheses / Efeito agudo da corrida ascendente: cenário atual e futuras hipóteses

Strategies for metabolic adjustments are often considered by athletes throughout a running event. Planning for such events during training does not always include variations from level training, even though up/downhill exertion should definitely be a part of such planning. The differentiation of training stimuli, under adverse conditions of intensity and inclination, can generate differentiated benefits. However, uphill running raises expectations of deleterious effects. The imposition of different slope gradients throughout running could generate increased metabolic demands for sports performance. Thus, the present study aimed to answer questions mainly about the acute effects of uphill running, its relationship with aerobic performance, allowing us to introduce new hypotheses for future studies in the area on the subject. Gaps still need to be filled concerning the relevance of uphill running, and its determinants. Many of the points presently under scrutiny only lead to speculative explanations; for logical reasons, more studies should focus on the prescription of training at different slopes. This is the point at which specific conditioning is required, because the regulation of the effort and the energy cost resulting from the imposition of uphill running during competitive races depends heavily on previous experiences. This review will cover recently published research on the subject.

RESUMO Estratégias para ajustes metabólicos são frequentemente consideradas por atletas ao longo de um evento de corrida. O planejamento de tais eventos durante o treinamento nem sempre inclui treinamento em planos inclinados, que deveriam compor esse planejamento. Adiferenciação dos estímulos de treinamento, em condições adversas de intensidade e inclinação, pode gerar benefíciosdiferenciados. No entanto, a corrida ascendente aumenta as expectativas de efeitos deletérios. Portanto, a imposição de diferentes gradientes de inclinação ao longo da corrida poderia gerar demandas metabólicas aumentadas paradesempenho esportivo. Assim, o presente estudo tevecomo objetivo responder questões principalmente sobre os efeitos agudos da corrida ascendente, sua relação com o desempenho aeróbio e a proposição de novas possíveis hipóteses para estudos futuros sobre o assunto. Muitaslacunas ainda precisam ser preenchidas sobre a relevância da corrida ascendente e seus determinantes. Muitas das questões apresentadas apenas levam a explicaçõesespeculativas; por razões lógicas, mais estudos devemse concentrar na prescrição de treinamento em face dediferentes porcentagens de inclinação. Este é o ponto em que o condicionamento específico é necessário, porquea regulação do esforço e do custo de energia resultanteda imposição de corrida ascendente durante corridascompetitivas depende fortemente das experiênciasanteriores.

Magnetic Resonance Imaging as an Index of Muscle Activation During Uphill and Downhill Running / 体力科学

The purpose of this study was to investigate the usage of the lower limb muscles (quadriceps femoris : QF, m. vastus lateralis : VL, m. rectus lemons : RF, m. vastus medialis : VM, m. vastus intermidialis : VI, hamstring : HM, m. gastrocnemius : UN, tihialis anterior : TA) and blood lactic acid concentration during uphill ( : UR +5 %) and downhill running ( : DR - 5 %) . We used magnetic resonance imaging (MRI) as one of the major indices. Seven healthy male volunteers participated in this study. T 2-weighted MR imaging, muscle surface temperature and blood lactic acid concentration were measured before and after UR and DR. In MRI imaging, the T2 value was defined as the area in which a high signal appeared after exercise.<BR>The value of the blood lactic acid concentration of UR was higher than that of DR (p<0.001) . After DR, the muscle surface temperature of RF was lower in comparison with other muscles (p< 0.05) . After UR, the T2 value of RF (p<0.05), HM (p<0.01) and UN (p<0.05) was higher than after DR exercise. During UR, a positive correlation (r=0.818) existed between the T 2 value of GN and blood lactic acid concentration (P<0.05) . During DR, a positive correlation (r=0.739) was also observed between the T 2 value of QF and blood lactic acid concentration (p<0.05) .<BR>From these results, we conclude that (1) the pattern of usage of lower limb muscles differs during UR and DR, (2) the most mobilized muscles in the lower limbs for UR are GN and HM, and (3) the most mobilized muscle in the lower limbs for DR is QF, respectively. These findings show that different exercises affect the blood lactic acid concentration differently.