The present study investigated the effects of high-intensity interval exercise training and placebo-exercise on mental health and inflammation using a randomized control trial. The study also examined how anxiety symptoms prior to high-intensity interval training may influence improvements in fitness. Inactive young adults underwent nine weeks of either high-intensity interval training or their regular routine. Questionnaires, a blood draw and a maximal exercise test were conducted the week before and week after the intervention. It was hypothesized those who underwent high-intensity interval training would experience greater reductions in their depression, anxiety, and inflammation than those who were in the placebo control group. It was also hypothesized those who had high anxiety symptoms at the start of high-intensity interval training would experience smaller improvements in fitness than those who had low anxiety symptoms.

Inclusion Criteria:

• Full-time student at McMaster University
• Speak, read and understand English

Exclusion Criteria:

• Exercising for more than 150 minutes of moderate-to-vigorous physical activity per week

The sharing of individual data with other researchers was not included in the informed consent signed by participants. Therefore, individual data will not be released.