Effects of maximal isometric contractions of the knee extensors on muscle damage and running economy after Downhill running

• Grant number: 16/04909-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 01, 2016
• End date: September 30, 2016
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Benedito Sérgio Denadai
• Grantee: Leonardo Coelho Rabello de Lima
• Supervisor: Ken Nosaka
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Institution abroad: Edith Cowan University, Joondalup (ECU), Australia
• Associated to the scholarship: 13/23585-4 - The relationship between running economy and strength: Utilizing a downhill runnin-induced muscle damage analysis model., BP.DR

Abstract

Muscle damage induced by downhill running decreases force production ability and running economy (RE). A recent study showed that 10 maximal isometric contractions at a long muscle length (ISOs) performed within a week prior to a damaging eccentric exercise of the elbow flexors, significantly attenuated symptoms of muscle damage (e.g. muscle soreness, force loss) in untrained individuals. However, no previous study has investigated whether ISOs confer protective effect on muscle damage induced by downhill running. The present will investigate if performing 10 ISOs of the knee extensors two days prior to a 30-min downhill (-15%) running attenuates the magnitude of muscle damage and changes in RE. Thirty male volunteers will be randomly assigned to either a control or an experimental group. The volunteers in the experimental group will perform 10 ISOs (3 s per contraction, 45 s between contractions) at 100° knee flexion on a leg press machine 2 days prior to the downhill run, while volunteers in the control group will remain inactive during this period. All volunteers will run downhill for 30 min at 70% of their maximal oxygen consumption speed. Changes in muscle damage markers (isokinetic peak torque of the knee extensors, countermovement jump height, muscle soreness, mid-thigh circumference, serum creatine kinase activity) and parameters associated with RE (oxygen uptake, ventilation, lactate concentration, perceived exertion, stride length and frequency) before, immediately after and 1-4 days after the downhill run will be compared between the groups. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LIMA, LEONARDO C. R.; NOSAKA, KAZUNORI; CHEN, TREVOR C.; PINTO, RONEI S.; GRECO, CAMILA C.; DENADAI, BENEDITO S.. Decreased running economy is not associated with decreased force production capacity following downhill running in untrained, young men. European Journal of Sport Science, FEB 2020. (16/04909-1, 13/23585-4)

LIMA, LEONARDO C. R.; BASSAN, NATALIA M.; CARDOZO, ADALGISO C.; GONCALVES, MAURO; GRECO, CAMILA C.; DENADAI, BENEDITO S.. Isometric pre-conditioning blunts exercise-induced muscle damage but does not attenuate changes in running economy following downhill running. HUMAN MOVEMENT SCIENCE, v. 60, p. 1-9, AUG 2018. (16/04909-1, 13/23585-4)