Can You Breathe Your Way To Better Health?

The purpose of this clinical trial is to explore the effects of either a 2-week high-intensity interval training (HIIT) or breath training intervention on measures of overall health, circulating biomarkers of stress, and immune function. Specific aims include: - Does a 2-week HIIT or breath training intervention improve measurements of overall health, including heart rate variability, physical activity, sleep quality, and severity of depression, anxiety, and stress? -Does a 2-week HIIT or breath training intervention improve circulating concentrations of stress-related biomarkers? Does a 2-week HIIT or breath training intervention improve immune function? Researchers will compare HIIT and breath training to see if equivalent immune improvements are observed. Participants will: -Undergo 2 weeks of HIIT or breath training interventions at a frequency of 3 times per week for 30 minutes or 5 times per week for 5 minutes if placed into an intervention group. -Undergo testing measures at the two pre- and post-intervention time points, if placed in the intervention groups or the healthy control group.