Effects of Fish Oil and Resistance Training on Muscle Mass and Function

Overview

This study consists of a free-living, 6-week fish oil (FO) or placebo (PLA) supplementation intervention alongside participants' habitual resistance exercise training (RET) regimens. Twenty young, healthy resistance-trained subjects who do not currently supplement with FO will be recruited to participate. An eligible participant will be between ages 18 and 35 and will have a minimum of two years of RET experience. Participants will be randomized into a FO group and a PLA group. The FO group will supplement with 4g/day of FO (4g fish oil concentrate: 2g EPA+ 1g DHA) and the PLA group will consume 4g/day of coconut oil (saturated fatty acids), as administered via gel capsules, in conjunction with their current RET program. Prior to intervention all participants will complete baseline biometric, strength, and neuromuscular testing. Participants will also have blood drawn to test for omega-3 fatty acid status, and complete and return a 3-day diet record and a physical activity recall. In order to monitor adherence to supplementation, FO and PLA bottles will also be returned weekly and pills will be counted. 3-day diet records will be obtained to ensure calorie and protein intakes remain consistent throughout the intervention period. Weekly physical activity records will also help to ensure consistency of participant training and to make sure all participants are following their training regimes in a progressive fashion. Following 6 weeks of FO or PLA supplementation, subjects will repeat all initial biometric, strength and neuromuscular testing, as well as a second, post-intervention blood draw.

Potential participants will report to the Human Performance Lab (HPL) in James Hall to complete the screening process. They will complete the informed consent form process with a member of the research team before providing any protected health information (PHI). The screening process has two components: questionnaires and physical measures. Potential participants will complete the following questionnaires: Stanford 7-Day Physical Activity Questionnaire and a Medical History Questionnaire. Participants will complete the following physical measures: height, weight, waist and hip circumference, and blood pressure will be assessed and followed by calculations of body mass index (BMI) and waist to hip ratio (WHR). The final measure will be a determination of fasting total cholesterol and blood glucose measured via capillary blood from a finger prick using an automated analyzer. The purpose of the screening process is to determine if a participant is healthy and can safely participate in exercise testing, and to determine their eligibility to participate in the study based on the criteria listed elsewhere. Participants who meet the eligibility criteria and are willing to participate will be enrolled in the study and randomly assigned to FO or PLA via block randomization methods. Enrolled participants will return to the HPL in the morning to complete a battery of biometric tests (described below) and will be given two logs to complete to collect baseline data: the Stanford 7-Day Physical Activity Questionnaire and a 3-day diet log. The purpose of the physical activity log is to determine their average level of physical activity and training program. The purpose of the 3-day diet log is to record their normal dietary intake and to provide practice for completing these logs as they will be completed on a weekly basis during the supplement intervention period. Participants will have the following physical measures recorded: height, weight, waist and hip circumference, body composition, and blood pressure. Participants will then have their resting metabolic rate (RMR) measured by indirect calorimetry. In preparation for this test participants will be asked to complete an overnight fast of at least 9 hours, abstain from caffeine for 12 hours and abstain from exercise and alcohol for 24 hours. Participants will be brought to a quiet room and asked to lie in a supine position for 30 minutes of rest. They will then be fitted with a breathing mask connected to the metabolic cart and their breath will be analyzed for 15 minutes while they continue to lie in a supine position. Their total energy expenditure will be calculated using their RMR and a physical activity factor based on their level of physical activity obtained from the Stanford 7-Day Physical Activity Questionnaire. Subject's total daily calorie requirements will then be verified using their 3-day diet record and the Mifflin-St. Jeor prediction equation. In order to ensure that participants are consuming enough calories in order to maintain their body weight during the 6-week supplementation period, the research team will use the average of participant's total calorimetric data (based on RMR), 3-day diet log, and the Mifflin-St. Jeor estimate. Participants will be sent pre-participation instructions before testing to ensure they arrive at the HPL with proper exercise attire and having abstained from caffeine for 12 hours and exercise and alcohol for 24 hours. They will report to the HPL to complete a 1RM test, a type of muscular strength assessment. This test will be performed for the back squat in a Smith machine with hand release breaks. Water will be provided and consumed ad libitum. Bench press and Squat will be completed with proper lifting technique as described by the National Strength and Conditioning Association (NSCA) guidelines. Participants' lower body neuromuscular function, assessed via maximal voluntary contraction (MVC) and rate of force development (RFD), will be completed through the use of force transducers applied to the legs. Participants will be seated in a custom-made wooden box with a single axis transducer attached to one of its surfaces (SM-500, Interface Inc., Scottsdale, Arizona, USA). When subjects sit on the box, their knee and hip joints will be at approximately 70° and 90° of flexion from full extension, respectively. Subjects will be asked to cross their arms across their chest during the testing. Dietary compliance will be monitored weekly during the free-living supplementation period using 3-day diet records and returned supplement pill bottles. 3-day diet records will be recorded by the participants and returned to the research team for analysis using professional nutrition analysis software (Food Processor, Oregon). Dietary analysis results will be discussed with the participant in order to help them adhere to dietary recommendations. Body weight measures will be recorded once per week to ensure a stable weight during the dietary intervention period. The participants will return supplement bottles weekly, and the research team will count and record any remaining capsules. Finally, physical activity logs will be collected every week to ensure diet and calorie recommendations are meeting the demands of RET.