A Pilot Study on In-Task Affect Predicting Free-Living Adherence to HIIT and MICT

Purpose: To report pilot test findings on whether in-task affect during a supervised exercise program, where participants were randomized to either moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT), predicts changes in moderate-to-vigorous physical activity (MVPA-Total and MVPA10+ in bouts of >= 10 min) at 1- and 6-month post-intervention.Method: This experimental study design randomized 32 inactive adults with prediabetes to complete a 2-week supervised MICT or HIIT plus behavioral counseling exercise intervention and objectively assessed free-living physical activity post-intervention. The Feeling Scale (FS) was used to assess the in-task effect. FS was measured in the middle of four, 1-min intervals in the HIIT condition, corresponding to similar to 20%, similar to 50%, similar to 75%, and similar to 85% of work out time. For the MICT condition, FS was assessed at similar exercise duration percentage times as HIIT. Accelerometer data evaluated MVPA at 1- and 6-month post-intervention.Results: 32 adults were included in the analyses. Pilot findings indicated in-task affect between the conditions did not predict changes in MVPA-Total from baseline to 1 and 6 months. For MVPA10+, in-task affect negatively predicted MVPA10+ over time in the MICT condition only.Conclusion: This study provides preliminary evidence that affect during MICT negatively predicts MVPA10+ over time, and that there is no difference of in-task affect's utility in predicting MVPA-Total between HIIT and MICT. Larger studies are required to confirm these findings.

Automated summary

The pilot test findings did not show that in-task affect during a supervised exercise program predicts changes in moderate-to-vigorous physical activity, but in the moderate-intensity continuous training condition, in-task affect negatively predicted high-intensity physical activity over time. Larger studies are needed to confirm these results.