Effect of Prolonged Military Exercises With High Load Carriage, on Neuromuscular Fatigue and Physiological/Biomechanical Responses

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.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: military equipment

• Study Type: Observational
• Enrollment (Actual): 10

Contacts and Locations

Study Locations

• France
  • Saint-Etienne, France, 42055
    • CHU de Saint-Etienne

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

• Sampling Method: Probability Sample

Study Population

military retreated from national army

Description

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

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Military	Other: military equipment; Military exercise of 24 hours

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Central fatigue quantification based on voluntary and electrically-induced force measurement on activated muscle.	after a a military exercise of 24 hours
Peripheral fatigue based on electrically-induced force measurement on the same muscle in relaxed condition.	after a a military exercise of 24 hours

Secondary Outcome Measures

Outcome Measure	Time Frame
Oxygen uptake, carbon-dioxide output, energetic-cost of locomotion and respiratory ratio, based on subject's gas exchanges.	after a a military exercise of 24 hours
Lactatemia, based on subject's arterialized capillary blood samples analysis	after a a military exercise of 24 hours
Muscular electrical activities, based on subject's surface EMG analysis	after a a military exercise of 24 hours
Heart rate frequence	after a a military exercise of 24 hours
Walking and running mechanics, measured by an instrumented treadmill	after a a military exercise of 24 hours
Postural equilibration, measured by a piezo-dynamometric double platform	after a a military exercise of 24 hours
Rate of perceived exertion, measured by the Borg scale ranging from 6 to 20	after a a military exercise of 24 hours
Perceived comfort, measured by a 10 cm visual analogic scale (VAS)	after a a military exercise of 24 hours

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Saint Etienne
• Investigators: Principal Investigator: Roger OULLION, Dr, CHU Saint-Etienne

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start: March 1, 2010
• Primary Completion (Actual): April 1, 2010
• Study Completion (Actual): April 1, 2010

Study Registration Dates

• First Submitted: May 11, 2010
• First Submitted That Met QC Criteria: May 19, 2010
• First Posted (Estimate): May 20, 2010

Study Record Updates

• Last Update Posted (Estimate): July 25, 2012
• Last Update Submitted That Met QC Criteria: July 24, 2012
• Last Verified: July 1, 2012

More Information

Terms related to this study

• Keywords: military exercises; neuromuscular fatigue; physiological responses; biomechanical responses; simulated military effort; high load carriage; Healthy voluntary
• Other Study ID Numbers: 0901110; 2009-A01346-51 (Other Identifier: AFSSAPS)