Katrina Taylor

High-intensity interval and moderate-intensity continuous training elicit similar enjoyment and adherence levels in overweight and obese adults

Abstract Background: High-intensity interval training (HIIT) has been shown to improve cardiometabolic health during supervised lab-based studies but adherence, enjoyment, and health benefits of HIIT performed independently are yet to be understood. We compared adherence, enjoyment, and cardiometabolic outcomes after 8 weeks of HIIT or moderate-intensity continuous training (MICT), matched for energy expenditure, in overweight and obese young adults. Methods: 17 adults were randomized to HIIT or MICT. After completing 12 sessions of supervised training over 3 weeks, participants were asked to independently perform HIIT or MICT for 30 min, 4 times/week for 5 weeks. Cardiometabolic outcomes included cardiorespiratory fitness (VO2 peak), lipids, and inflammatory markers. Exercise enjoyment was measured by the validated Physical Activity Enjoyment Scale. Results: Exercise adherence (93.4 ± 3.1% vs. 93.1 ± 3.7%, respectively) and mean enjoyment across the intervention (100.1 ± 4.3 vs. 100.3 ± 4.4, respectively) were high, with no differences between HIIT and MICT (p > .05). Similarly, enjoyment levels did not change over time in either group (p > .05). After training, HIIT exhibited a greater decrease in low-density lipoprotein cholesterol than MICT (−0.66 mmol L−1 vs. −0.03 mmol L−1, respectively) and a greater increase in VO2 peak than MICT (p < .05, +2.6 mL kg min−1 vs. +0.4 mL kg min−1, respectively). Interleukin-6 and C-reactive protein increased in HIIT (+0.5 pg mL−1 and + 31.4 nmol L−1, respectively) and decreased in MICT (−0.6 pg mL−1 and −6.7 nmol L−1, respectively, p < .05). Conclusions: Our novel findings suggest that HIIT is enjoyable and has high unsupervised adherence rates in overweight and obese adults. However, HIIT may be associated with an increase in inflammation with short-term exercise in this population.

The Decremental Protocol as an Alternative Protocol to Measure Maximal Oxygen Consumption in Athletes

PURPOSE To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample. METHODS Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05. RESULTS There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg-1 · min-1) and decremental (60.82 ± 8.49 mL · kg-1 · min-1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials. CONCLUSIONS The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.

Efficacy of High-intensity Interval Training on Exercise Enjoyment, Adherence and Cardiometabolic Health in Overweight Adults: 2133 Board #285 June 2, 3: 30 PM - 5: 00 PM.

CONCLUSION: Baseline scores for BID suggest women in this study were generally unsatisfied with their overall body image (BASS < 3.0, BSQ > 80). In general, BT and ATRT produced similar responses; exercise reduced CBS—thereby reducing the difference between CBS and IBS—improving overall body satisfaction regardless of changes in body composition. Supported by the Robert and Patricia Hines Endowment in Kinesiology.