Potential Utility of Self-Report Measures of Affect to Optimise Exercise Adherence in People with Type 2 Diabetes

Can In-Task Affect During Interval and Continuous Exercise Predict 12-Month Physical Activity Behavior? Findings from a Randomized Trial

BACKGROUND

In-task affective responses to moderate-intensity continuous exercise training (MICT) have been shown to predict future physical activity behavior. However, limited research has investigated whether this affect-behavior relationship is similar for high-intensity interval training (HIIT) and whether it holds true over the longer term. This study aims to determine (1) if in-task affect during 2 weeks of supervised MICT and HIIT predicted changes to unsupervised moderate-to-vigorous physical activity (MVPA) behavior 12 months post-intervention and (2) if this predictive relationship was moderated by exercise type (MICT vs. HIIT).

METHOD

Ninety-nine adults (69.7% female; 50.9 ± 9.4 years) who were low active and overweight were randomized to 2 weeks of exercise training of MICT (n = 52) or HIIT (n = 47), followed by 12 months of accelerometry-assessed free-living MVPA.

RESULTS

The pooled moderation model was not significant, F(3, 94) = 2.54, p = .07 (R2 = 0.085), with a non-significant group by affect interaction (p = .06). The conditional effect for MICT was significant (B = 17.27, t = 2.17, p = .03), suggesting that 12-month change in MVPA increased by 17.27 min/week for every one-point increase in in-task affect. The conditional effect for HIIT was not significant (p = .85), suggesting that in-task affect was not predictive of 12-month change in MVPA.

CONCLUSION

The current findings raise important questions about whether the affect-behavior relationship may vary depending on exercise type. For HIIT-based exercise in particular, additional psychological constructs beyond in-task affect should be considered when attempting to predict future physical activity behavior.

Development and Feasibility of a Regulated, Supramaximal High-Intensity Training Program Adapted for Older Individuals

Background: High-intensity training (HIT) with extremely short intervals (designated here as supramaximal HIT) is a time-efficient training method for health and performance. However, a protocol for regulation and control of intensity is missing, impeding implementation in various groups, such as older individuals. Methods: This study presents the development and characteristics of a novel training protocol with regulated and controlled supramaximal intervals adapted for older people. Using both quantitative and qualitative analyses, we explored the feasibility of the program, performed in a group training setting, with physically active older individuals (aged 65-75, n = 7; five women). The developed supramaximal HIT program consisted of 10 × 6 s cycle sprint intervals with ∼1 min of active recovery with the following key characteristics: (1) an individual target power output was reached and maintained during all intervals and regulated and expressed as the percentage of the estimated maximum mean power output for the duration of the interval (i.e., 6 s); (2) pedaling cadence was standardized for all participants, while resistance was individualized; and (3) the protocol enabled controlled and systematic adjustments of training intensity following standardized escalation criteria. Aim: Our aim was to test the feasibility of a novel training regimen with regulated and controlled supramaximal HIT, adapted for older people. The feasibility criteria for the program were to support participants in reaching a supramaximal intensity (i.e., power output > 100% of estimated VO2 max), avoid inducing a negative affective response, and have participants perceive it as feasible and acceptable. Results: All feasibility criteria were met. The standardized escalation procedure provided safe escalation of training load up to a supramaximal intensity (around three times the power output at estimated VO2 max). The participants never reported negative affective responses, and they perceived the program as fun and feasible. Conclusion: This novel program offers a usable methodology for further studies on supramaximal HIT among older individuals with different levels of physical capacity. Future research should explore the effects of the program in various populations of older people and their experiences and long-term adherence compared with other forms of training.