Effects of exercise mode, energy, and macronutrient interventions on inflammation during military training.
Load carriage (LC) exercise may exacerbate inflammation during training. Nutritional supplementation may mitigate this response by sparing endogenous carbohydrate stores, enhancing glycogen repletion, and attenuating negative energy balance. Two studies were conducted to assess inflammatory responses to acute LC and training, with or without nutritional supplementation. Study 1: 40 adults fed eucaloric diets performed 90-min of either LC (treadmill, mean ± SD 24 ± 3 kg LC) or cycle ergometry (CE) matched for intensity (2.2 ± 0.1 VO2peak L min(-1)) during which combined 10 g protein/46 g carbohydrate (223 kcal) or non-nutritive (22 kcal) control drinks were consumed. Study 2: 73 Soldiers received either combat rations alone or supplemented with 1000 kcal day(-1) from 20 g protein- or 48 g carbohydrate-based bars during a 4-day, 51 km ski march (~45 kg LC, energy expenditure 6155 ± 515 kcal day(-1) and intake 2866 ± 616 kcal day(-1)). IL-6, hepcidin, and ferritin were measured at baseline, 3-h post exercise (PE), 24-h PE, 48-h PE, and 72-h PE in study 1, and before (PRE) and after (POST) the 4-d ski march in study 2. Study 1: IL-6 was higher 3-h and 24-h post exercise (PE) for CE only (mode × time, P < 0.05), hepcidin increased 3-h PE and recovered by 48-h, and ferritin peaked 24-h and remained elevated 72-h PE (P < 0.05), regardless of mode and diet. Study 2: IL-6, hepcidin and ferritin were higher (P < 0.05) after training, regardless of group assignment. Energy expenditure (r = 0.40), intake (r = -0.26), and balance (r = -0.43) were associated (P < 0.05) with hepcidin after training. Inflammation after acute LC and CE was similar and not affected by supplemental nutrition during energy balance. The magnitude of hepcidin response was inversely related to energy balance suggesting that eating enough to balance energy expenditure might attenuate the inflammatory response to military training.
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts stefan.m.pasiakos.civ@mail.mil.
Stefan M
SM
Pasiakos
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
Lee M
LM
Margolis
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
Nancy E
NE
Murphy
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
Holy L
HL
McClung
Norwegian Defence Research Establishment, Kjeller, Norway.
Svein
S
Martini
Norwegian Defence Research Establishment, Kjeller, Norway.
Yngvar
Y
Gundersen
Thermal Mountain and Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
John W
JW
Castellani
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
James P
JP
Karl
Norwegian Defence Research Establishment, Kjeller, Norway.
Hilde K
HK
Teien
Norwegian Defence Research Establishment, Kjeller, Norway.
Elisabeth H
EH
Madslien
General Defence Material/Catering and Combat Feeding Section, Norwegian Navy, Rødskiferveien, Norway.
Pal H
PH
Stenberg
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
Andrew J
AJ
Young
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
Scott J
SJ
Montain
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts.
James P
JP
McClung
D000293:Adolescent; D000328:Adult; D004032:Diet; D019587:Dietary Supplements; D002149:Energy Intake / Q000187:drug effects / Q000502:physiology; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D005293:Ferritins / Q000097:blood; D064451:Hepcidins / Q000097:blood; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008889:Military Personnel; D064797:Physical Conditioning, Human / Q000502:physiology*; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
D064451:Hepcidins; D015850:Interleukin-6; D005293:Ferritins
Endurance exercise; energy deficit; iron status; macronutrients