Work

Validity and reliability of V˙O2max determination immediately after a maximal fat oxidation assessment in pre-diabetes/type 2 Diabetes Mellitus population

Year: 2025

Type: article

Abstract: Background Measuring maximal fat oxidation (MFO) and maximal oxygen consumption ( V ˙ O 2max ) typically requires two separate days, which can be time-consuming. This study aimed to assess the validity and reliability of a single-day test for measuring MFO and V ˙ O 2max in individuals with pre-diabetes/type 2 diabetes (T2DM). Methods Twenty adults with pre-diabetes/T2DM (10 women; [53.1 ± 8.8] years) participated in this cross-sectional study. Participants underwent a single-day MFO- V ˙ O 2max protocol, followed by the traditional V ˙ O 2max test on a cycle ergometer 4–7 days later, with both assessments performed using indirect calorimetry . The single-day test commenced with the MFO test, involving 15 W per 3 min increments until the respiratory exchange rate reached 1.0. After a 5-minute (min) rest, the V ˙ O 2max test was conducted, starting at the last load and increasing by 15 W·min -1 until voluntary exhaustion. The traditional V ˙ O 2max test involved a 15 W·min -1 n incremental protocol until voluntary exhaustion, followed by a verification test at 110% of the previous maximum load. Results No significant differences were observed between MFO- V ˙ O 2max and traditional V ˙ O 2max protocol in V ˙ O 2max values ([2 099.4 ± 534.1] ml·min -1 vs. [2 119.1 ± 548.3] ml·min -1 , p = 0.715) or heart rate ([163.2 ± 18.2] beat/min vs. [164.5 ± 16.1] beat/min, p = 0.485). The MFO- V ˙ O 2max protocol test demonstrated excellent reliability (intraclass correlation coefficient = 0.957), limits of agreement ranging from 300.06 ml·min -1 to −306.77 ml·min -1 , and the standard error of measurement was 181.67 ml·min -1 . Conclusions Therefore, the single-day test is a valid and reliable method for assessing both MFO and V ˙ O 2max in men and women with pre-diabetes/T2DM. With a mean total duration of (34 ± 8) min, this test enhances clinical applicability by significantly reducing the time and cost associated with traditional assessments.

Source: Sports Medicine and Health Science

DOI: 10.1016/j.smhs.2025.02.004