Marksmanship deficits caused by an exhaustive whole-body lifting task with and without torso-borne loads.
J Strength Cond Res
; 26 Suppl 2: S30-6, 2012 Jul.
Article
in En
| MEDLINE
| ID: mdl-22614225
ABSTRACT
Studies of exhaustive exercise on marksmanship are inconclusive and have not measured trigger pull latencies (LAT) nor considered impact of added torso loads. This study examined the impact of exhaustive whole-body exercise and torso loading on accuracy, precision, and latency during a marksmanship test. Twelve men lifted a 20.5-kg box on to a 1.55-m high shelf until they could not maintain a 12 lifts·min⻹ pace. Within 25 seconds of ending the lifting task, the subjects started a 10-minute rifle marksmanship test (8 shots·min⻹). During lifting and shooting, the subjects wore 2 different loads NOLOAD = boots, uniform, and helmet (5.9 kg) and LOAD = a torso-borne load (29.9 kg) + NOLOAD. With the LOAD, the subjects were only able to work for 69% as long, perform 31% as many lifts, or do 38% as much total work compared with the NOLOAD condition. Despite performing less total external work during LOAD, the heart rate (HR) was more than 25% higher than NOLOAD. Measures of accuracy and precision improved and stabilized after minute 3. Overall, LAT increased (p < 0.025) for LOAD (mean ± SE, 2,522 ± 81 milliseconds), compared with NOLOAD (2,240 ± 121). During 0-4 minutes, LAT for LOAD was 14% greater than for NOLOAD (p < 0.05); from 4 to 10 minutes, LAT did not differ. Exhaustive whole-body exercise transiently degraded accuracy regardless of load. In the LOAD condition, LAT was immediately increased and sustained for 10 minutes; in the NOLOAD condition, LAT increased gradually. Although load did not decrease accuracy, it increased the time to engage targets, which can impact fighting effectiveness and survivability.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Psychomotor Performance
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Weight-Bearing
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Lifting
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Torso
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Military Personnel
Limits:
Adult
/
Humans
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Male
Language:
En
Journal:
J Strength Cond Res
Journal subject:
FISIOLOGIA
Year:
2012
Document type:
Article
Affiliation country:
United States