Low-frequency High-Intensity Interval Training in Overweight or Obese Young Adults

Purpose: In a sample of healthy adolescents, the authors aimed to investigate the effects of high-intensity interval exercise (HIIE) training and detraining on baroreflex sensitivity (BRS) and it’s vascular and autonomic components at rest. Methods: Nineteen volunteers were randomly allocated to (1) 4 weeks HIIE training performed 3 times per week or (2) a control condition with no intervention for the same duration as HIIE training. PRE, POST, and following 2 weeks of detraining resting supine heart rate and blood pressure were measured, and a cross-spectral method (integrated gain [gain in low frequency]) was used to determine BRS gain. Arterial compliance (AC) was assessed as the BRS vascular component. LFgain divided by AC (LFgain/AC) was used as the autonomic determinant of BRS. Results: The HIIE training was completed with 100% compliance. HIIE did not change resting gain in low frequency (LFgain) (P = .66; effect size = 0.21), AC (P = .44; effect size = 0.36), or LFgain/AC (P = .68; effect size = 0.19) compared to control. Conclusion: Four weeks of HIIE training does not change BRS and its autonomic and vascular determinant in a sample of healthy adolescents at rest.

Download Full-text

Short-Term, Equipment-Free High Intensity Interval Training Elicits Significant Improvements in Cardiorespiratory Fitness Irrespective of Supervision in Early Adulthood

Frontiers in Sports and Active Living ◽

10.3389/fspor.2021.697518 ◽

2021 ◽

Vol 3 ◽

Author(s):

Tanvir S. Sian ◽

Thomas Inns ◽

Amanda Gates ◽

Brett Doleman ◽

Nima Gharahdaghi ◽

...

Keyword(s):

Young Adults ◽

Blood Glucose ◽

Cardiorespiratory Fitness ◽

High Intensity ◽

Plasma Insulin ◽

Interval Training ◽

Cardiometabolic Health ◽

Control Group ◽

High Intensity Interval Training ◽

High Intensity Interval

Introduction: Serious health implications from having low levels of cardiorespiratory fitness (CRF) and being overweight in young adulthood are carried forward into later life. High-intensity interval training (HIIT) is a time-effective, potent stimulus for improving CRF and indices of cardiometabolic health. To date, few studies have investigated the use of equipment-free HIIT or the impact of supervision for improving CRF via HIIT.Methods: Thirty healthy young adults (18–30 y) were randomised to 4 weeks (12 sessions) equipment-free, bodyweight based supervised laboratory HIIT (L-HIIT), unsupervised home HIIT (H-HIIT) or no-intervention (CON). Utilised exercises were star jumps, squats and standing sprints. Measurements of CRF (anaerobic threshold (AT) and VO2peak), blood pressure (BP), body mass index (BMI), blood glucose and plasma insulin by oral glucose tolerance test (OGTT), and muscle architecture were performed at baseline and after the intervention.Results: When compared to the control group, both HIIT protocols improved CRF (AT: L-HIIT mean difference compared to the control group (MD) +2.1 (95% CI: 0.34–4.03) ml/kg/min; p = 0.02; H-HIIT MD +3.01 (1.17–4.85) ml/kg/min; p = 0.002), VO2peak: L-HIIT (MD +2.94 (0.64–5.25) ml/kg/min; p = 0.01; H-HIIT MD +2.55 (0.34–4.76) ml/kg/min; p = 0.03), BMI (L-HIIT MD −0.43 (−0.86 to 0.00) kg/m2; p = 0.05; H-HIIT: MD −0.51 (−0.95 to −0.07) kg/m2; p = 0.03) and m. vastus lateralis pennation angle (L-HIIT MD 0.2 (0.13–0.27)°; p < 0.001; H-HIIT MD 0.17 (0.09 to 0.24)°; p < 0.001). There was no significant change in BP, blood glucose or plasma insulin in any of the groups.Conclusions: Four weeks time-efficient, equipment-free, bodyweight-based HIIT is able to elicit improvements in CRF irrespective of supervision status. Unsupervised HIIT may be a useful tool for counteracting the rise of sedentary behaviours and consequent cardiometabolic disorders in young adults.

Download Full-text

Comparing the Impact of Heart Rate-Based In-Game Adaptations in an Exergame-Based Functional High-Intensity Interval Training on Training Intensity and Experience in Healthy Young Adults

Frontiers in Psychology ◽

10.3389/fpsyg.2021.572877 ◽

2021 ◽

Vol 12 ◽

Author(s):

Anna Lisa Martin-Niedecken ◽

Tiziana Schwarz ◽

Alexandra Schättin

Keyword(s):

Heart Rate ◽

Young Adults ◽

High Intensity ◽

Interval Training ◽

Whole Body ◽

Intensity Level ◽

High Intensity Interval Training ◽

Individual Parameter ◽

High Intensity Interval ◽

The Impact

Physical inactivity remains one of the biggest societal challenges of the 21st century. The gaming industry and the fitness sector have responded to this alarming fact with game-based or gamified training scenarios and thus established the promising trend of exergaming. Exergames—games played with the (whole) body as physical input—have been extolled as potential attractive and effective training tools. Simultaneously, researchers and designers are still exploring new approaches to exploit the full potential of this innovative and enjoyable training method. One way to boost the attractiveness and effectiveness of an exergame is to individualize it with game adaptations. A physiological parameter that is often used to balance the physical challenge and intensity of exergames to the player’s fitness skills is the heart rate (HR). Therefore, researchers and designers often rely on age-based, maximum HR (HRmax) formulas originating from performance diagnostics. In combination with the player’s assessed real-time HR during an exergame session, the pre-determined HRmax is used to adapt the game’s challenge to reach a pre-defined HR and physical intensity level (in-exergame adaptations), respectively. Although the validity and reliability of these age-based HRmax formulas were proven in heterogeneous target populations, their use is still often criticized as HR is an individual parameter that is affected by various internal and external factors. So far, no study has investigated whether the formula-based pre-calculated HRmax compared to a standardized individually pre-assessed HRmax elicits different training intensities, training experiences, and flow feelings in an exergame. Therefore, we compared both variants for in-exergame adaptation with the ExerCube – a functional high-intensity interval training exergame – in healthy young adults. Comparing the results of the two conditions, no significant differences were found for HR parameters and perceived physical and cognitive exertion, nor for overall flow feelings and physical activity enjoyment. Thus, the formula-based in-exergame adaptation approach was suitable in the presented study population, and the ExerCube provided an equally reliable in-exergame adaptation and comparable exergame play experiences. We discuss our findings in the context of related work on exergame adaptation approaches and draw out some implications for future adaptive exergame design and research topics.

Download Full-text