Skeletal Muscle Adaptations to Peptide-Supplemented Resistance Exercise Training

Skeletal muscle size, an important metabolic tissue, is governed by the balance between two opposing processes, muscle protein synthesis and muscle protein breakdown. In response to long-term resistance exercise (weightlifting), skeletal muscle growth is commonly observed and it is believed that this is due to increases in muscle protein synthesis which leads to a positive net protein balance stimulating muscle growth. Due to its links to overall metabolic health, maximising muscle growth in response to resistance exercise training has become a significant focus in recent times, with various dietary supplements proposed due to their additive effects on muscle growth with resistance training. Protein supplementation, most commonly whey protein, is the most popular dietary supplement utilised by individuals completing resistance exercise training, however, more recent research has suggested that specific components of whey protein, as well as other foodstuffs, have the potential to individually activate growth pathways within skeletal muscle. This study will investigate whether daily supplementation with a combination of these compounds is able to produce greater muscle growth, compared to a placebo, when combined with resistance exercise training. We will also investigate whether this supplement can also produce greater increase in strength as well as studying the potential mechanisms behind any of these preferential adaptations in muscle samples which will be collected before and after the training period.

Inclusion Criteria: * Aged 18-35 years * Body Mass Index (BMI, calculated by research team based on height and weight) between 18.5-27.4 kg.m-2 * Meeting UK physical activity guidelines (150 mins moderate or 75 mins vigorous activity/week) * Not currently participating in structured progressive resistance exercise training or have regularly participated in previous 6 months * In good health, being free from disease or conditions (e.g., Type-II diabetes, hyper/hypothyroidism, irritable bowel syndrome, polycystic ovary syndrome) which influence skeletal muscle metabolism or digestion (self-declared) Exclusion Criteria: * Have an allergy to ingredients of the supplement or placebo supplement (e.g., legume/bean, corn allergies) * Have used dietary supplements which are known to affect skeletal muscle recovery and exercise adaptations (e.g., creatine) within the previous month * Are a smoker/vaper or have a history of smoking/vaping in previous year * Have a respiratory condition (e.g., asthma, chronic obstructive pulmonary disease) * Using hormone therapy (not including birth control), anabolic steroids, or recreational drugs * Are pregnant or currently breastfeeding * Are currently trying to conceive a child * Have any injury or body weakness which prevents participation in full body resistance exercise * Have a known allergy to lidocaine