Clinical trials

Resistance exercise training (RET) in children and adolescents has become a popular activity, with a growing body of evidence supporting its use. Numerous studies indicate that it is safe and effective at increasing muscular strength, improving sport performance, and mitigating injury risk. Despite this evidence, there are still many unknowns with RET in children, including its mechanisms of action in enhancing muscle strength. Neural and muscular mechanisms can improve muscle strength following RET. Neural factors include improved recruitment and firing of an individual's muscle cells, and muscular factors primarily include an increase in the size of the muscle (hypertrophy). In children, little is known about how these mechanisms relate to muscle strength. Therefore, the purpose of this study is to non-invasively assess the mechanisms of RET-induced strength increases in children performing 12 weeks of RET, compared with a non-training control group. Broadly, muscular adaptations will be assessed using ultrasound measures, while neural mechanisms will be assessed using surface electromyography decomposition.

Physical activity and dairy consumption during growth and development are each known to improve peak bone mass in young adults. Peak bone mass, the maximum amount of bone a person will have in their lifetime, is typically reached in the early 20's in females and late 20's in males. However, evidence suggests that young people do not consume enough dairy to maximize their bone mass. The resulting effect in peak bone mass can be troublesome, particularly for athletes, such as volleyball players. This study aims to determine whether increased dairy consumption combined with training can have an additive effect on the physiology of young competitive athletes. Specifically, we will examine whether Greek yogurt consumption will lead to beneficial changes in bone metabolism and inflammation, in adolescent and young adult, male and female athletes, similar to those observed with whey protein supplementation. Many athletes choose exclusively protein supplementation and miss out on other nutrients vital for healthy growth and development. By examining the benefits of Greek yogurt across different athlete age groups and sexes, this work will help reshape the attitudes, beliefs, and behaviours surrounding diet of young athletes.

Resistance exercise training (RET) in children and adolescents has become a popular area of research, with a growing body of evidence supporting its use. Position and consensus statements about RET for children indicate that it is safe and effective at increasing muscular strength, improving sport performance, and mitigating injury risk. Neural and muscular mechanisms can improve muscle strength following RET. Neural factors include improved recruitment and firing of an individual's motor units, and muscular factors primarily include an increase in the size of the muscle (hypertrophy). In children, little is known about how these mechanisms relate to muscle strength. There is very little evidence of morphological changes following RET in children. Therefore, conventional wisdom is that children rely only on neural factors to improve strength following RET. Nevertheless, some studies have suggested RET-induced muscle hypertrophy in children and adolescents, indicating that with certain training protocols, children may achieve muscle growth. Hypertrophy of muscle fibres occurs when the rate of muscle protein synthesis (MPS) is greater than the rate of protein breakdown, and is enhanced with the ingestion of dietary amino acids. Due to ethical concerns with obtaining muscle samples (i.e., from muscle biopsies) in pediatric populations, MPS rates have not been previously assessed following RET in children. Recent advancements in stable-isotope methodology (specifically, leucine) allow for the estimation of MPS in a non-invasive breath test. The objective of the proposed research is to examine the effects of an acute bout of RET on leucine retention (a proxy for MPS) in children, adolescents, and adults using a non-invasive breath test.