DEXA Body Composition Changes Among 140 Conscripts

Abstract

The aim of the study was to determine changes in body composition and physical fitness during military service. A prospective cohort study of 140 healthy male conscripts was conducted. We examined subject characteristics, aerobic performance and muscle strength, and assessed body composition using dual-energy X-ray absorptiometry (DEXA) three times. Conscripts’ mean baseline weight (79.5 kg) decreased by 2 kg during the first 3 months, but increased by 0.9 kg during the second 3-month period (p<0.001). Fat mass measured by DEXA decreased by 3.2 kg during the first but increased by 0.8 kg during the second 3-month period (p<0.001). Throughout the 6-month study, an increase was seen in distance of 12-min run test (from 2 380 m to 2 530 m; p<0.001), and muscle strength score (from 6.5 to 9.5 p<0.001). Finnish military training seems to have beneficial effects on physical fitness. However, considering the relatively modest changes in body fat and physical fitness seen in conscripts with average BMIs at baseline, design of diverse training programmes for the varying baseline BMI levels are warranted to improve the physical fitness results.

Key words

dual-energy X-ray absorptiometry (DEXA) - body mass index - fat mass - military personnel - physical fitness

References

• 1 Chan GM. Performance of dual-energy X-ray absorptiometry in evaluating bone, lean body mass, and fat in pediatric subjects.  J Bone Miner Res. 1992;  7 369-374
• 2 Cooper KH. A means of assessing maximal oxygen intake. Correlation between field and treadmill testing.  JAMA. 1968;  203 201-204
• 3 Cooper KH. Testing and developing cardiovascular fitness within the United States Air Force.  J Occup Med. 1968;  10 636-639
• 4 Faff J, Korneta K. Changes in aerobic and anaerobic fitness in the Polish army paratroopers during their military service.  Aviat Space Environ Med. 2000;  71 920-924
• 5 Haarbo J, Gotfredsen A, Hassager C, Christiansen C. Validation of body composition by dual energy X-ray absorptiometry (DEXA).  Clin Physiol. 1991;  11 331-341
• 6 Liesinen K, Hyppönen H, Kalmari K, Santtila M, Pimiä M, Leskinen A. The Handbook of Finnish Conscript (in Finnish). Helsinki: The Finnish Defence Forces 2003
• 7 Kautiainen S, Rimpela A, Vikat A, Virtanen SM. Secular trends in overweight and obesity among Finnish adolescents in 1977-1999.  Int J Obes. 2002;  26 544-552
• 8 Kiebzak GM, Leamy LJ, Pierson LM, Nord RH, Zhang ZY. Measurement precision of body composition variables using the lunar DPX-L densitometer.  J Clin Densitom. 2000;  3 35-41
• 9 Lee L, Kumar S, Leong LC. The impact of five-month basic military training on the body weight and body fat of 197 moderately to severely obese Singaporean males aged 17–19 years.  Int J Obes Relat Metab Disord. 1994;  18 105-109
• 10 Lim CL, Lee LK. The effects of 20 weeks basic military training program on body composition, VO2max and aerobic fitness of obese recruits.  J Sports Med Phys Fitness. 1994;  34 271-278
• 11 Louis O, Verlinde S, Thomas M, Schepper J De. Between-centre variability versus variability over time in DXA whole body measure-ments evaluated using a whole body phantom.  Eur J Radiol. 2006;  58 431-434
• 12 Mattila VM, Tallroth K, Marttinen M, Pihlajamaki H. Body composition by DEXA and its association with physical fitness in 140 conscripts.  Med Sci Sports Exerc. 2007;  39 2242-2247
• 13 Mazess RB, Barden HS, Bisek JP, Hanson J. Dual-energy X-ray absorptiometry for total-body and regional bone-mineral and soft-tissue composition.  Am J Clin Nutr. 1990;  51 1106-1112
• 14 Santtila M, Kyrolainen H, Vasankari T, Palvalin K, Hakkinen A, Hakkinen K. Physical fitness profiles in young Finnish men during the years 1975–2004.  Med Sci Sports Exerc. 2006;  38 1990-1994
• 15 Svendsen OL, Haarbo J, Hassager C, Christriansen C. Accuracy of measurements of total-body soft-tissue composition by dual energy X-ray absorptiometry in vivo.  Basic Life Sci. 1993;  60 381-383
• 16 Svendsen OL, Haarbo J, Heitmann BL, Gotfredsen A, Christiansen C. Measurement of body fat in elderly subjects by dual-energy X-ray absorptiometry, bioelectrical impedance, and anthropometry.  Am J Clin Nutr. 1991;  53 1117-1123
• 17 Williams AG. Effects of basic training in the British Army on regular and reserve army personnel.  J Strength Cond Res. 2005;  19 254-259

Correspondence