Clinical trial NCT01127191: Effect of Prolonged Military Exercises With High Load Carriage, on Neuromuscular Fatigue and Physiological/Biomechanical Responses
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Healthy
Keywords: military exercises
neuromuscular fatigue
physiological responses
biomechanical responses
simulated military effort
high load carriage
Healthy voluntary
Lead sponsor: Centre Hospitalier Universitaire de Saint Etienne
Sponsor class: OTHER
First posted: 2010-05-20
Enrollment: 10
Sex: MALE
Minimum age (years): 30
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: military retreated from national army

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: Central fatigue quantification based on voluntary and electrically-induced force measurement on activated muscle.
timeFrame: after a a military exercise of 24 hours
measure: Peripheral fatigue based on electrically-induced force measurement on the same muscle in relaxed condition.
timeFrame: after a a military exercise of 24 hours
Secondary outcomes:
measure: Oxygen uptake, carbon-dioxide output, energetic-cost of locomotion and respiratory ratio, based on subject's gas exchanges.
timeFrame: after a a military exercise of 24 hours
measure: Lactatemia, based on subject's arterialized capillary blood samples analysis
timeFrame: after a a military exercise of 24 hours
measure: Muscular electrical activities, based on subject's surface EMG analysis
timeFrame: after a a military exercise of 24 hours
measure: Heart rate frequence
timeFrame: after a a military exercise of 24 hours
measure: Walking and running mechanics, measured by an instrumented treadmill
timeFrame: after a a military exercise of 24 hours
measure: Postural equilibration, measured by a piezo-dynamometric double platform
timeFrame: after a a military exercise of 24 hours
measure: Rate of perceived exertion, measured by the Borg scale ranging from 6 to 20
timeFrame: after a a military exercise of 24 hours
measure: Perceived comfort, measured by a 10 cm visual analogic scale (VAS)
timeFrame: after a a military exercise of 24 hours
Other outcomes:
Locations:
city: Saint-Etienne
country: France
facility: CHU de Saint-Etienne
Study officials:
affiliation: CHU SAINT-ETIENNE
name: Roger OULLION, Dr
role: PRINCIPAL_INVESTIGATOR
References:
citation: Grenier JG, Millet GY, Peyrot N, Samozino P, Oullion R, Messonnier L, Morin JB. Effects of extreme-duration heavy load carriage on neuromuscular function and locomotion: a military-based study. PLoS One. 2012;7(8):e43586. doi: 10.1371/journal.pone.0043586. Epub 2012 Aug 22.