Muscle Glycogen, Fiber Type, Aerobic Fitness, and Anaerobic Capacity of West Coast U.S. Navy Sea-Air-Land Personnel (SEALS).
Abstract
Thirty-eight Navy SEALs performed aerobic fitness and maximal anaerobic capacity tests on a cycle ergometer. Lactic acid concentration was measured in blood samples taken during the aerobic fitness test. After recording prior dietary intake and physical activity, thirty-six subjects had biopsies taken from the vastus lateralis muscle. Biopsy results showed that SEALs averaged 55% fast twitch muscle fiber type. The muscle samples had a mean glycogen concentration of 404 (+ or - 124) mmol(dot)kg-1. Biopsy results show that SEALs have an unremarkable fiber type composition and a muscle glycogen concentration that may put them at risk of insidious glycogen depletion over successive deployment days. Muscle glycogen concentration was significantly correlated with 2-day dietary carbohydrate (CHO) intake normalized for body weight. Blood lactate concentration during submaximal exercise suggests that SEALs' aerobic fitness was somewhat low; anaerobic capacity tests show that SEALs would benefit from: (a) increasing CHO intake to enhance premission muscle glycogen; and (b) engaging in combined aerobic/anaerobic training using established principles of mode specificity, frequency, intensity, and duration of exercise. Muscle glycogen, SEALs, Diet, Fiber type, Fitness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1992
- Accession Number
- ADA258364
Entities
People
- Harold W. Goforth Jr.
- Ira Jacobs
- W. .k. Prusaczyk
Organizations
- Naval Health Research Center