High rates of stress-related problems in college students and low utilization of treatment options show a need for simple, effective interventions for stress management. Both exercise and breathing biofeedback have proven effective in reducing state anxiety in the past, but have never been compared. The purpose of this study was to evaluate the efficacy of brief exercise and breathing biofeedback interventions on altering state anxiety and affect in high-stress, college students. Thirty-two participants (mean age=21.5±3.2 years; 21 female) experienced the following 10-minute interventions on separate days: self-paced walk (EX), breathing biofeedback (BF) and a placebo condition of quiet study (QS). Anxiety and affect data were gathered using the State Anxiety Inventory (SAI) and Activation Deactivation Adjective Checklist (AD-ACL), respectively, before (Pre), immediately after (Post0), and 15 minutes after (Post15) the intervention in each condition. Heart rate variability (HRV) was measured at 2 time points (Pre- and Post-intervention). Mixed-factor Condition (3) x Time (3) repeated-measures ANOVAs were run on State Anxiety and Affect. Condition (3) x Time (2) ANOVAs were performed on HRV variables. Follow up time (3) repeated-measures ANCOVAs were run on EX and BF conditions for State Anxiety and Affect variables with HRV variables as covariates.

Findings demonstrated that BF reduced anxiety, with the effect size for the BF condition nearly double that of the EX condition (Pre to Post15: BF d=-.39, EX d=-.21). Secondly, the EX condition increased Energy from Pre to Post0 (d = .68) that then returned to baseline by Post15. In contrast, the BF condition showed a temporary increase in Calmness (d = .5). The QS condition produced no change in state anxiety or affect constructs. Finally, change over time was seen in the pNN50 variable indicating that, regardless of the intervention, a short break from normal stressors can increase HRV. However, changes in HRV did not explain the improvements in psychological states. In conclusion, the findings of the present study provide evidence for the benefits of acute bouts of both self-paced exercise and respiration biofeedback in improving anxiety and affect in high-stress college students. The mechanisms underlying these effects remain unclear.