[Introduction] The modern lifestyle increases body fat in both obese and non-obese individuals. An increase in adipose tissue and decrease in muscle mass may further cause to decrease in peripheral uptake of glucose and insulin resistance. It is well known that exercises are efficient in reducing body fat and preserving fat-free body mass. There are a great number of studies with acute metabolic responses in whole body exercises. However, the metabolic responses especially in lipid to exercised muscle after the localized exercise have seldom been studied. In theory, a dynamic response of lipid oxidation in exercised muscle can be higher as compared to non-exercised muscle because exercising muscle needs more energy from within-the same muscle in order to maintain a level of ATP quickly. Nevertheless, there is no information available how the metabolic response occurs in intracellular lipid of exercised muscle after the localized repetitive muscle contractions. Magnetic resonance spectroscopy (MRS) offers to assess metabolism non-invasively. The purpose of this study was to use single voxel proton MRS to assess the lipid metabolic changes of the triceps muscle in young women before and after elbow extension exercise. Such knowledge will contribute to our understanding of local muscle metabolism in exercised muscle, which may provide new information to prevent metabolic disorders. [Methods] Twenty-one young healthy women volunteered for this study. The upper arm was assessed before and immediately after dynamic elbow extension exercise by a 1.5-Tesla Signa HDx MR scanner (GE Medical Systems). The entire upper arm was encased in a receive-only 4-channel shoulder coil. By using a water and lipid-suppressed double-spin echo point resolved spectroscopy (PRESS) sequence, intramyocellular lipid (IMCL) and extramyocellular lipid (EMCL) values of the triceps muscle were calculated. Subject performed dynamic elbow extension without carrying any load for 30 minutes long and paced at over 60 contractions per minute. Subject positioned at lying in the prone and forearm of the exercise arm was hanging down from the bed. Also, blood glucose and lactate were measured before and after exercise. [Results] After dynamic exercises, IMCL values of triceps changed; however, such responses were varied individually. Blood glucose decreased significantly after the exercise, but not blood lactic acid. [Discussion] Changes in IMCL value of triceps and blood glucose after dynamic exercise of upper arm may suggest some local metabolic responses in exercised muscle. Further studies require the possibility of local lipid metabolic response in the exercised muscles.