Effects of winter military training on energy balance, whole-body protein balance, muscle damage, soreness, and physical performance.
Physiological consequences of winter military operations are not well described. This study examined Norwegian soldiers (n = 21 males) participating in a physically demanding winter training program to evaluate whether short-term military training alters energy and whole-body protein balance, muscle damage, soreness, and performance. Energy expenditure (D2(18)O) and intake were measured daily, and postabsorptive whole-body protein turnover ([(15)N]-glycine), muscle damage, soreness, and performance (vertical jump) were assessed at baseline, following a 4-day, military task training phase (MTT) and after a 3-day, 54-km ski march (SKI). Energy intake (kcal·day(-1)) increased (P < 0.01) from (mean ± SD (95% confidence interval)) 3098 ± 236 (2985, 3212) during MTT to 3461 ± 586 (3178, 3743) during SKI, while protein (g·kg(-1)·day(-1)) intake remained constant (MTT, 1.59 ± 0.33 (1.51, 1.66); and SKI, 1.71 ± 0.55 (1.58, 1.85)). Energy expenditure increased (P < 0.05) during SKI (6851 ± 562 (6580, 7122)) compared with MTT (5480 ± 389 (5293, 5668)) and exceeded energy intake. Protein flux, synthesis, and breakdown were all increased (P < 0.05) 24%, 18%, and 27%, respectively, during SKI compared with baseline and MTT. Whole-body protein balance was lower (P < 0.05) during SKI (-1.41 ± 1.11 (-1.98, -0.84) g·kg(-1)·10 h) than MTT and baseline. Muscle damage and soreness increased and performance decreased progressively (P < 0.05). The physiological consequences observed during short-term winter military training provide the basis for future studies to evaluate nutritional strategies that attenuate protein loss and sustain performance during severe energy deficits.
a Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA.
Lee M
LM
Margolis
Nancy E
NE
Murphy
Svein
S
Martini
Marissa G
MG
Spitz
Ingjerd
I
Thrane
Susan M
SM
McGraw
Janet-Martha
JM
Blatny
John W
JW
Castellani
Jennifer C
JC
Rood
Andrew J
AJ
Young
Scott J
SJ
Montain
Yngvar
Y
Gundersen
Stefan M
SM
Pasiakos
D004044:Dietary Proteins; D002149:Energy Intake; D004734:Energy Metabolism; D006801:Humans; D008297:Male; D008889:Military Personnel; D009135:Muscular Diseases / Q000378:metabolism*; D063806:Myalgia / Q000378:metabolism; D010809:Physical Fitness; D012621:Seasons; D055815:Young Adult
D004044:Dietary Proteins
apport nutritionnel recommandé; azote; dietary protein; nitrogen; protéines alimentaires; recommended dietary allowance; stress