Abstract
Data obtained in primarily Caucasian (C) and African American adults show that ethnicity does not mediate responsiveness to exercise training. It is unknown if Hispanics (H), who face elevated health risks and are less active than C, exhibit a similar response to exercise training. This study compared cardiorespiratory and hemodynamic responses to high intensity interval training (HIIT) between C and H women. Twelve C and ten H women ages 19–35 yr who were non-obese and inactive completed nine sessions of HIIT over a 3 wk period. Maximal oxygen uptake (VO2max) was assessed twice at baseline during which thoracic impedance was used to evaluate heart rate (HR), stroke volume (SV) and cardiac output (CO). Habitual physical activity was assessed using accelerometry. Results showed a significant main effect of training for VO2max in C and H (F = 13.97, p = 0.001) and no group by training interaction (p = 0.65). There was a main effect of training for CO and SV in C and H (F = 7.57, p = 0.01; F = 7.16, p = 0.02), yet post hoc analyses revealed significant increases were only exhibited in C. There was a tendency for a group by training interaction for a-VO2diff (F = 1.32, p = 0.054), and a large effect size was seen in H (d = 1.02). Overall, data show no effect of ethnicity on changes in VO2max with low-volume HIIT, yet C and H may achieve this outcome differently. Longer studies in similar populations are needed to verify this result.
Highlights
About 25% of adults meet the current Physical Activity Guidelines which suggest a minimum of 150 minutes of moderate intensity continuous training (MICT), 75 minutes of vigorous exercise, or a combination of both to achieve various health benefits [1]
An alternative to MICT is high intensity interval training (HIIT), defined as repeated, brief, and intense exercise bouts separated by active recovery
The average peak heart rate during training was equal to 164.6 ± 9.9 b/min (89.8% of HRmax), which verifies the intensity of HIIT (Fig 2)
Summary
About 25% of adults meet the current Physical Activity Guidelines which suggest a minimum of 150 minutes of moderate intensity continuous training (MICT), 75 minutes of vigorous exercise, or a combination of both to achieve various health benefits [1]. Lack of physical activity increases risk of heart disease, stroke, type-2 diabetes, and certain cancers which increase morbidity and all-cause mortality [2]. Despite these well-documented benefits of MICT, many individuals express a perceived lack of time as a primary barrier to regular physical activity [3]. Compared to MICT, increases in VO2max are frequently superior [6, 7] in response to HIIT despite the lower training volume. Enjoyment is a multifactorial outcome, this characteristic of HIIT is critical to broaden its application to the general population, as exercise adherence is related to enjoyment [10]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call