Inter-individual variability of aerobic capacity after rehabilitation exercise training in children with severe burn injury

Eric Rivas; Julia Kleinhapl; Oscar E Suman-Vejas

doi:10.1016/j.burns.2024.05.018

Inter-individual variability of aerobic capacity after rehabilitation exercise training in children with severe burn injury

Burns. 2024 Jun 10:S0305-4179(24)00173-6. doi: 10.1016/j.burns.2024.05.018. Online ahead of print.

Authors

Eric Rivas¹, Julia Kleinhapl², Oscar E Suman-Vejas³

Affiliations

¹ Microgravity Research, Axiom Space, Houston, TX 77058, USA. Electronic address: ericrivas.phd@gmail.com.
² Department of Surgery, Division of Surgical Science, University of Texas Medical Branch, Galveston, TX 77555, USA; Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, Graz, Austria.
³ Department of Surgery, Division of Surgical Science, University of Texas Medical Branch, Galveston, TX 77555, USA.

PMID: 39353796
DOI: 10.1016/j.burns.2024.05.018

Abstract

Introduction: Severe burn trauma damages resting and exercise cardiac function that may affect long term cardiovascular health. The implementation of rehabilitation exercise training (RET) soon after hospital discharge improves cardiorespiratory fitness; however, it does not fully restore aerobic capacity and presents large inter-individual variability. We tested the hypothesis that the inter-individual variability of aerobic capacity for responders (R) compared to nonresponders (NR) would differ for exercise frequency and intensity.

Methods: Thirty-three children (11 female, [mean±SD] 12 ± 3 years, 145 ± 18 cm, 40 ± 11 kg, 49 ± 31 BMI percentile) with severe burns (49 ± 15 % total body surface area burned, with 35 ± 22 % third-degree burns) completed a 6-week RET program. Cardiorespiratory fitness (peak VO₂) was measured before and after RET. Frequency (session days/week), intensity (% peak heart rate), time (min/session), and volume (min/week) were compared between responders and non-responders. Significance was set at p < 0.05.

Results: Sixty-four percent of the study population improved peak VO2 after RET whereas 36 % showed no improvements. Using a 2-way factorial ANOVA (group [G] × week [WK]), we found that exercise frequency and session time were similar and increased slightly over 6 weeks between R and NR (main effect for WK; P < 0.002). Exercise volume was significantly lower on week 2 for NR compared to R (G × WK interaction, P < 0.028). Exercise intensity over 6-weeks was significantly lower in the NR compared to the R group (G × WK interaction, P < 0.022).

Conclusions: Exercise intensity and volume may be important contributors for improving the interindividual response to exercise training for peak VO₂. These data suggest that the appropriate dose-response requirement for exercise intensity may be > 80 % peak heart rate and exercise volume of > 150 min per week. Further understanding of the exercise prescription will provide insights important for cardiovascular rehabilitation in children with severe burns.

Subject code: Inter-individual Variability, Exercise, Pediatrics, Exercise Training.

Keywords: Cardiovascular; Exercise response; Pediatric burns.