Land military missions generally combine prolonged walking/moderate-pace-running and other physical actions such as creeping, jumping, shooting,… which are associated with the direct carrying of high to severe loads of equipment and supplies (20-30 to 50 kg) by soldiers. For an infantry section, "typical" intervention phases last about 20-24 h and combine variable intensity grades. Consequently, military mission characteristics are an interesting investigation field of human fatigue. Previous studies have investigated human neuromuscular alterations after prolonged "normal" locomotion exercises [Millet et al., 2004, 2009], thus the aim of this study is to characterize the neuromuscular determinants of fatigue induced by a 24-h Simulated Military Effort (SME) and a 4-h Military Road March (MM), both performed with high load carriage. Additionally, the consequences of fatigue on physiological and biomechanical parameters of locomotion will be investigated.

Inclusion Criteria:

• to be a male
• to have a VO2max > 45ml/min/kg (mean observed value in military subjects)
• to be aged from 30 to 45
• to be recently retreated from National Army
• to be highly experienced in military efforts
• to be trained in exercises involving load carrying
• to benefit from a social security insurance

Exclusion Criteria:

• All subjects with recent (< 3 month) bone, articular or muscle diseases.
• All subjects presenting a clinic sign of intolerance to testing procedures, especially subjects with knee, ankle, hip or back diseases.
• All subjects intolerant to muddy or wooded environment.
• All subjects presenting a clinic sign of intolerance to exercise, and particularly to running or walking while carrying a load
• All subjects involved at the same time in another medical research
• All subjects militarily active
• All subjects with cardiac or pulmonary identified and known diseases

military retreated from national army