Protein Source and Resistance Training

Background Protein supplements and particularly whey protein supplements are frequently consumed by athletes and recreationally active adults to achieve greater gains in muscle mass and strength as well as improved physical performance. Lean red meat has the equivalent essential amino acid and branched chain amino acids as whey protein, and additionally contains creatine, beta-alanine and several essential vitamins and minerals which are important for health and performance. Therefore, the preferential addition of lean red meat to the diet as opposed to whey protein supplements may provide the same and possibly greater benefits and would be in line with the recommended 'food first approach' endorsed by Sport Ireland and the World Anti-Doping Agency among others.

Aim The overall aim of this study is to explore whether lean red meat augments adaptation to resistance training in recreationally active young adults undergoing resistance training. Additionally, the investigators aim to investigate changes in nutritional intakes and status of selected micronutrients in response to increased consumption of lean red meat.

Methods

A total of n=72 recreationally active men and women (50% male) will be recruited to this single-blinded intervention study with a parallel design. Participants will be randomized to consume one of three treatments:

• lean red meat,
• a whey protein supplement, or
• an isocaloric maltodextrin control beverage and will complete a 12-week resistance training programme.

Measurements: Body composition and muscle thickness will be measured using bioelectrical impedance analysis and ultrasound respectively. Additionally, skinfold measurements will be used to estimate body fat percentage. Vertical jump height, isokinetic strength and 1 repetition maximums will be completed to assess muscle contractile properties namely explosive and maximal strength. Blood pressure will also be measured at baseline and post intervention. Finally, dietary intake will be recorded at selected timepoints, and blood tests will be used to characterise status of selected micronutrients, blood lipids, and inflammation markers. All measures will be performed before and at the end of a 12-week resistance training intervention during which all participants will engage in resistance exercise 3 days per week and consume their assigned treatment on each of those training days.

Conclusion By investigating the impact of lean red meat on exercise adaptation and nutrition status of a number of selected micronutrients this study can contribute to the understanding of the role of lean red meat in performance nutrition. Additionally, this study can more broadly contribute to our understanding of the "food first" approach as it relates to recreationally active men and women.

Inclusion criteria

• a. Aged between 18 to 35 years old. b. Have completed either no or low level only resistance training in the previous 6 months.

c. Are not using any protein or performance/recovery enhancing supplements or willing to stop use for duration of the study.

d. Willing to consume study treatment for duration of the study. e. Willing to perform resistance training. f. Must be able and willing to provide written informed consent to participate.

Exclusion criteria

• Have any notable health concern or disability which may conceivably increase risk to the participant and/or affect outcomes.
• Has performed resistance training in the past 6 months at a moderate or high level.
• Is a smoker.
• Is unwilling or unable to perform full body resistance training.
• Is pregnant or planning to become pregnant during the study period.
• Has a food allergy or intolerance that may place participant at risk to consume any of the study treatments.
• Is post-menopausal or currently undergoing menopause.
• Follows a vegetarian or meat-avoidant diet.