Int J Sports Med 2018; 39(12): 916-923
DOI: 10.1055/a-0660-0031
Training & Testing
© Georg Thieme Verlag KG Stuttgart · New York

Peak Fat Oxidation is not Independently Related to Ironman Performance in Women

Stine Dahl Vest
1  X-lab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
,
Jacob Frandsen*
1  X-lab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
,
Steen Larsen
1  X-lab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
3  Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland
,
Flemming Dela
1  X-lab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
2  Department of Geriatrics, Bispebjerg University Hospital, Copenhagen, Denmark
,
Jørn Wulff Helge
1  X-lab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
› Author Affiliations
Further Information

Publication History



accepted 06 July 2018

Publication Date:
18 September 2018 (online)

Abstract

The aim of the present study was to investigate if peak fat oxidation rate (PFO) is related to Ironman performance in female athletes. Thirty-six female Ironman athletes (age: 34±1 yrs, [21–45 yrs.] SEM [Range]) with a BMI of 22.1±2.0 kg/m2 [18.8–28.4 kg/m2], a body fat percentage of 24.8±1.0% [9.0–37.0%] and a V̇O2peak of 53.0±1.3 ml/min/kg [36.5–70.5 ml/min/kg] were tested in the laboratory prior to the Ironman Copenhagen 2017. Race time ranged from 9:17:07 to 15:23:48 with mean race time being 11:57:26 h:min:s (717 min). By simple linear regression analyses we found associations between race time and P FO (r2=0.22, p<0.005), V̇O2peak (r2=0.65, p<0.0001) and the relative exercise intensity eliciting PFO (Fatmax) (r2=0.35, p=0.0001). Furthermore, associations were found between race time and body fat percentage (r2=0.44, p<0.0001) and age (r2=0.16, p<0.05). By means of multiple regression analysis, V̇O2peak was the only statistically significant variable explaining 64% of the variation in race time (adj. r2=0.64, p<0.005). In conclusion, these results demonstrate that PFO is not independently related to Ironman performance in a heterogeneous group of female athletes. Interestingly, V̇O2peak alone was able to predict 64% of the variation in Ironman race times.

* Shared first authorship.