Doctor of Philosophy (PhD)


School of Kinesiology

Document Type



Mitochondrial function, a vital determinant of an individual’s health and fitness, can be compromised by dysfunction in an individual’s mitochondria, leading to various cardiometabolic disorders such as cardiovascular disease, diabetes, obesity, etc. However, the good news is that regular physical activity is a powerful tool in maintaining and even improving an individual’s mitochondrial function. It can counteract the detrimental effects of chronic sedentary behavior and the decline of natural aging, which can significantly decrease mitochondrial function. Endurance and resistance exercises have been observed to cause significant improvements when an individual follows a long-term training intervention.

The first study, particularly relevant to our understanding of the relationship between physical activity and mitochondrial function, examined the effect of an acute amount of maximal intensity training on immune cell bioenergetics and phenotype. Collegiate swimmers performed a Bucket test, in which their blood was drawn before and immediately after for analysis. The results were striking, with increased circulating PBMC, particularly in central memory and senescent cells. On a cellular level, routine respiration increased in cells, but on a tissue level, all respiratory states increased except for the LEAK state. This could indicate that the overall increase in immune cell respiration following maximal exercise could be due to the mobilization of specific cell types.

The second study, with direct implications for healthcare professionals and older adults, examined the effect of low-intensity exercise breaks combined with resistance exercise on oxidative capacity in older adults. Adults 65+ years were put into one of three groups: resistance training only (RE), resistance and aerobic exercise (AE), and resistance and low-intensity physical activity breaks (REALPA) for a 16-week training intervention. The results were encouraging, with all groups showing overall improvements in body composition, muscular strength, as well as skeletal muscle oxidative phosphorylation and electron transport capacity. These trends were similar in both the resistance + aerobic exercise group and the resistance + low-intensity physical activity breaks.



Committee Chair

Irving, Brian

Available for download on Thursday, April 01, 2027