Individual responses for a) change in exercise HR and b) lipid oxidation in response to 12 wk of high-volume interval training.

<p>Individual responses for a) change in exercise HR and b) lipid oxidation in response to 12 wk of high-volume interval training.</p

Individual responses for a) change in exercise HR and b) lipid oxidation in response to 2 wk of low-volume interval training.

<p>Individual responses for a) change in exercise HR and b) lipid oxidation in response to 2 wk of low-volume interval training.</p

Individual responses in VO₂max, exercise HR, and fat oxidation to high-volume HIT in sedentary women.

<p>R = responder; NR = non-responder; eHR = exercise heart rate; note that the columns refer to individual participants.</p><p>High volume HIT = 12 weeks of 3 sessions/wk of 6–10 1-min bouts @ 60–90% W_max.</p

High-Intensity Interval Training Elicits Higher Enjoyment than Moderate Intensity Continuous Exercise

<div><p>Exercise adherence is affected by factors including perceptions of enjoyment, time availability, and intrinsic motivation. Approximately 50% of individuals withdraw from an exercise program within the first 6 mo of initiation, citing lack of time as a main influence. Time efficient exercise such as high intensity interval training (HIIT) may provide an alternative to moderate intensity continuous exercise (MICT) to elicit substantial health benefits. This study examined differences in enjoyment, affect, and perceived exertion between MICT and HIIT. Twelve recreationally active men and women (age = 29.5 ± 10.7 yr, VO₂max = 41.4 ± 4.1 mL/kg/min, BMI = 23.1 ± 2.1 kg/m²) initially performed a VO₂max test on a cycle ergometer to determine appropriate workloads for subsequent exercise bouts. Each subject returned for two additional exercise trials, performing either HIIT (eight 1 min bouts of cycling at 85% maximal workload (Wmax) with 1 min of active recovery between bouts) or MICT (20 min of cycling at 45% Wmax) in randomized order. During exercise, rating of perceived exertion (RPE), affect, and blood lactate concentration (BLa) were measured. Additionally, the Physical Activity Enjoyment Scale (PACES) was completed after exercise. Results showed higher enjoyment (p = 0.013) in response to HIIT (103.8 ± 9.4) versus MICT (84.2 ± 19.1). Eleven of 12 participants (92%) preferred HIIT to MICT. However, affect was lower (p<0.05) and HR, RPE, and BLa were higher (p<0.05) in HIIT versus MICT. Although HIIT is more physically demanding than MICT, individuals report greater enjoyment due to its time efficiency and constantly changing stimulus.</p><p><b><i>Trial Registration</i>:</b><a href="https://clinicaltrials.gov/ct2/show/NCT:02981667" target="_blank">NCT:02981667</a>.</p></div

Physical characteristics of participants (N = 12).

<p>Physical characteristics of participants (N = 12).</p

Flow chart describing participant recruitment.

<p>Flow chart describing participant recruitment.</p