Efficacy of eat-on-move ration for sustaining physical activity, reaction time, and mood.
Repeated carbohydrate feedings and caffeine have been shown to increase self-paced physical activity. Whether a field ration pack that promotes snacking of these items would enhance physical activity remains unclear.


OBJECTIVE
Evaluate the effectiveness of a ration pack consisting of eat-on-move items to promote snacking, as well as caffeine items, as a nutritional strategy to improve performance.


METHODS
Twenty-eight wildland firefighters consumed both an eat-on-move ration (first strike ration (FSR): 13.2 MJ, 420 g CHO, 665 mg caffeine daily) and entrée-based ration (meals, ready-to-eat (MRE): 11.9 MJ, 373 g CHO, 100 mg caffeine daily) for 2 d separated by 1 d. Diet order was counterbalanced. Outcome measurements included self-paced physical activity determined by actimetry, reaction time, number of eating occasions using dietary recall, and dietary intake from food wrapper collection.


RESULTS
Total eating episodes were higher with FSR compared with MRE (P = 0.013; mean +/- SD: 8.2 +/- 1.3 vs 7.6 +/- 1.1 episodes x 2 d(-1)), as were 2-d energy intake (22.0 +/- 2.4 vs 18.4 +/- 2.5 MJ; P < 0.01), carbohydrate intake (698 +/- 76 vs 546 +/- 82 mg; P < 0.01), self-reported caffeine intake (347 +/- 262 vs 55 +/- 65 mg; P < 0.01), and average end-shift salivary caffeine (1.6 +/- 1.9 vs 0.7 +/- 1.0 microg x mL(-1); P < 0.01). Total activity counts were higher (P = 0.046) when consuming FSR (507,833 +/- 129,130 counts per shift) compared with MRE (443,095 +/- 142,208 counts per shift). This was accomplished by spending a greater percentage of work shift with activity counts >1000 counts x min(-1) (21 +/- 8% vs 18 +/- 6%; P = 0.01) and less percent of work shift <50 counts x min(-1) (33 +/- 10% vs 38 +/- 10%; P = 0.01).


CONCLUSIONS
Delivery of energy and caffeine in a manner that promotes snacking behavior is advantageous for increasing self-selected physical activity during arduous labor.
1Military Nutrition Division, USARIEM, Natick, MA 01760-5007, USA. scott.montain@us.army.mil
Scott J
SJ
Montain
Carol J
CJ
Baker-Fulco
Philip J
PJ
Niro
Andrew R
AR
Reinert
John S
JS
Cuddy
Brent C
BC
Ruby
D000328:Adult; D054874:Athletic Performance; D002110:Caffeine / Q000008:administration & dosage; D015444:Exercise; D005247:Feeding Behavior / Q000502:physiology / Q000523:psychology; D005260:Female; D018857:Food Packaging; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires; D055815:Young Adult
D002110:Caffeine