The long-term effect of an exercise and diet intervention in asthma patients: a 1-year follow-up on a randomised controlled trial

BACKGROUND: In the EFFORT (Effects of Exercise and Diet in Nonobese Asthma Patients – A Randomized Controlled Trial) study, maximum exercise capacity (V′(O(2))(max)) increased significantly within a 2-month high-intensity spinning period. Furthermore, the study concluded that only the combined exercise and diet intervention improved asthma control, significantly. This study examined whether original improvements in V′(O(2))(max) and asthma control were present 1 year after intervention completion. METHOD: In the original trial, 149 patients were randomised into four study groups. Participants were assessed with an incremental cycle ergometer test and the Asthma Control Questionnaire (ACQ). Of the 149 patients, 66 accepted the follow-up invitation. Participants were distributed in their original groups: exercise group (n=18), diet group (n=117), combined diet and exercise group (n=115) and the control group (n=110). Patients were assessed with original procedures. Though, upon measuring V′(O(2))(max), the original four study groups were merged into one spinning group (n=127) and one nonspinning group (n=133). RESULTS: Comparing the spinning and nonspinning group, there was no significant between-group difference in V′(O(2))(max), at 1-year follow-up (p=0.3). In addition, there was no significant between-group difference in ACQ score (p=0.6). Hence, in the combined group, the initial improvement in the ACQ score had regressed to pre-intervention values within 1 year from study completion. CONCLUSION: There were no measurable long-lasting effects on V′(O(2))(max) 1 year after the intervention was completed. Furthermore, there was no long-lasting effect of the combined intervention on asthma control.