Association Between Anemia And Physical Fitness Performance

Abstract

INTRODUCTION: Anemia has been implicated in adverse health outcomes of competitive athletes and military recruits ranging from overuse injuries to limited endurance. PURPOSE: To investigate the prevalence of anemia among United States Air Force (USAF) basic trainees and to compare physical fitness performance and attrition rates between anemic and non-anemic trainees. METHODS: All USAF basic trainees were screened for anemia between July 2013 and January 2014 at the start of an 8-week basic training program at Lackland Air Force Base, TX. Age, sex, body mass index, screening hemoglobin (Hgb), initial and final USAF physical fitness test scores, and attrition (i.e., failure to complete training) were collected on all trainees. Those identified as anemic (Hgb <13.5 g/dL for males and <12.0 g/dL for females) received additional lab screening, nutritional counseling and oral iron-replacement therapy per clinic protocol. Mean percent improvement was calculated for all fitness parameters from beginning to end of training, and anemic trainees were compared to non-anemic trainees by paired t-test with Welch modification. Results were stratified by sex and anemia severity. RESULTS: Overall prevalence of anemia was 12.6% (N=18,827). Stratified by severity [borderline (BA), moderate (MA), and severe (SA)], respective prevalence was 12.6%, 10.9% and 1.9% for females and 4.8%, 3.8% and 0.3% for males. Mean 1.5-mile run time and push-up and sit-up counts improved significantly from beginning to end of training for both anemic and non-anemic trainees (p<0.001 for both). Mean run time improved between 13.2% and 17.7% for all trainees. Trainees without anemia had slightly greater run time improvements than those with BA and MA (female: 17.7% vs. 15.2% and 15.1% improvement, p<0.05 for both; male: 14.9% vs. 13.2% and 13.5% improvement, p<0.05 for both). Females with BA and MA, and males with BA, had statistically significant improvements in sit-ups as compared to their counterparts without anemia. Females with MA had statistically significant improvements in push-ups compared to non-anemics. Attrition for anemic trainees was 9.0%, as compared to 5.6% for those without anemia. CONCLUSION: Anemia was prevalent among USAF basic trainees. Identification and treatment of anemia may optimize physical performance.