High-intensity interval training for adolescents with asthma: effective at increasing aerobic fitness but no influence on arterial stiffness or clustered cardiometabolic risk
Two studies from researchers at the Asthma UK Centre for Applied Research have found that high-intensity interval training was well-tolerated by adolescents with asthma but did not influence the firming of the walls of the arteries
Publications in the Journal of Sport and Health Science and the European Journal of Applied Physiology describe studies that evaluated the effectiveness of a 6-month high-intensity interval training (HIIT) intervention. The studies investigated the effect of the intervention on those with and without asthma, and its effect on their cardiometabolic risk (the risk of having cardiovascular events such as a heart attack or stroke) and arterial stiffness.
Both studies involved participants from the X4A trial: eXercise for Asthma with Commando Joe’s.
Effectiveness of HIIT training
This trial was the first to evaluate the effectiveness of a 6-month field-based HIIT intervention in adolescents with asthma compared with their healthy peers. It involved a total of 616 adolescents, including 155 with asthma, who were recruited from 5 schools as part of a randomised controlled trial. The 221 intervention participants completed three 30-minute sessions per week. The participants were measured before, during and immediately and 3 months after the intervention for:
- 20-metre shuttle run
- Body mass index (BMI)
- Lung function
- Paediatric Quality of Life Inventory
- Paediatric Asthma Quality of Life Questionnaire
- Asthma Control Questionnaire
Those with asthma did not have any differences in their aerobic fitness compared to those without asthma at any point during the study, but they did tend to have a higher BMI. The intervention improved the maximal aerobic fitness for all participants, but there was no change in lung function or quality of life, irrespective of participants’ asthma status.
The BMI of the intervention group was maintained through the six-month trial. The control group BMI, for those both with and without asthma, increased during the intervention. At the three-month follow-up, all groups (intervention, control, asthma, no asthma) had a significantly greater BMI than before the intervention began.
Cardiometabolic risk or arterial stiffness
The second study involved 65 of the participants from the previous trial, including 31 with asthma. It investigated the effect of six months of HIIT on the stiffness of their arteries and on their risk of having an issue with their heart (cardiometabolic risk).
Arterial stiffness, or how rigid the walls of the arteries are, has been suggested as a powerful tool to indicate structural changes in the arterial system. Asthma is increasingly reported to be associated with a higher arterial stiffness in children and traditional aerobic exercise can improve children’s arterial stiffness. This is the first study to examine whether HIIT has an effect on clustered cardiometabolic risk and arterial stiffness in adolescents with asthma and their healthy counterparts.
This study has found that the cardiometabolic health of adolescents is not influenced by asthma status. Instead, it is dependent on seven clusters of factors:
- blood pressure/stroke volume
- markers of adiposity (being severely overweight or obese)
- hemodynamic/arterial stiffness
- wave reflection
The participants’ asthma status did not influence the cardiometabolic response to the HIIT intervention.
These studies demonstrate that HIIT may be an effective tool for increasing peak aerobic fitness and preventing an increase in BMI in adolescents, irrespective of asthma. They also show that adolescents with controlled, mild asthma do not demonstrate any discernible differences in arterial stiffness compared to their healthy peers.
They also indicate that asthma does not influence aerobic fitness or trainability in young people, hopefully decreasing the stigmatization of those with asthma.
Professor Melitta McNarry, a member of the Centre who is based at Swansea University, was the Principle Investigator for both of these studies. She said:
“These studies highlight the need for more research into the most effective strategies to sustainably maintain aerobic fitness and health through the promotion of physical activity and exercise, and avoidance of prolonged periods spent sedentary, in youth with asthma. Importantly, these studies suggest that asthma status should not be a reason for exclusion from exercise-based interventions for those with well-controlled, mild asthma.”
Dr Charles Winn, a former PhD student with the Centre, was involved in these studies, and these publications were outputs from his thesis. Read more about Charles’ PhD project.
Read these papers
- Charles O.N. Winn, Kelly A. Mackintosh, William T.B. Eddolls, Gareth Stratton, Andrew M. Wilson, Melitta A. McNarry**, Gwyneth A. Davies**. Effect of high-intensity interval training in adolescents with asthma: The eXercise for Asthma with Commando Joe's® (X4ACJ) trial. Journal of Sport and Health Science. Volume 10, Issue 4, 2021, Pages 488-498, ISSN 2095-2546, doi: 10.1016/j.jshs.2019.05.009.
**Joint last authors
- McNarry, M.A., Lester, L., Ellins, E.A. et al. Asthma and high-intensity interval training have no effect on clustered cardiometabolic risk or arterial stiffness in adolescents. Eur J Appl Physiol 121, 1967–1978 (2021). doi: 10.1007/s00421-020-04590-4