Search Results

You are looking at 1 - 5 of 5 items for :

Clear All
Restricted access

Julia Zakrzewski and Keith Tolfrey

Consensus on the exercise protocol used to measure Fatmax (exercise intensity corresponding to maximum fat oxidation (MFO)) in children has not been reached. The present study compared Fatmax estimated using the 3 min incremental cycling protocol (3-INC) and a protocol consisting of several 10 min constant work rate exercise bouts (10-CWR) in 26 prepubertal children. Group Fatmax values were the same for 3-INC and 10-CWR (55% VO2peak) and 95% limits of agreement (LoA) were ± 7% VO2peak. Group MFO values were similar between protocols, although 95% LoA were -94 to 113 mg·min−1. While 3-INC provides a valid estimation of Fatmax compared with 10-CWR, caution should be exercised when estimating MFO in prepubertal children.

Restricted access

Francisco J. Amaro-Gahete, Lucas Jurado-Fasoli, Alejandro R. Triviño, Guillermo Sanchez-Delgado, Alejandro De-la-O, Jørn W. Helge and Jonatan R. Ruiz

Purpose: To analyze the diurnal variation of maximal fat oxidation (MFO) and the intensity that elicits MFO (Fatmax) in trained male athletes. Methods: A total of 12 endurance-trained male athletes age 24.7 (4.1) y participated in the study. The authors measured MFO, Fatmax, maximum oxygen uptake (VO2max), and VO2 percentage at ventilatory threshold 2 with a graded exercise protocol performed on 2 days separated by 1 wk. One test was performed in the morning and the other in the afternoon. The authors assessed the participants’ chronotype using the HÖME questionnaire. Results: MFO and Fatmax were greater in the afternoon than in the morning (Δ = 13%, P < .001 and Δ = 6%, P = .001, respectively), whereas there were similar VO2max and ventilatory threshold 2 in the morning, than in the afternoon test (Δ = 0.2%, P = .158 and Δ = 7%, P = .650, respectively). There was a strong positive association between VO2max and MFO in both morning and afternoon assessments (R 2 = .783, P = .001 and R 2 = .663, P < .001, respectively). Similarly, there was a positive association between VO2max and Fatmax in both morning and afternoon assessments (R 2 = .406, P = .024 and R 2 = .414, P = .026, respectively). Conclusion: MFO and Fatmax may partially explain some of the observed diurnal variation in the performance of endurance sports.

Restricted access

Andrés Pérez, Domingo J. Ramos-Campo, Cristian Marín-Pagan, Francisco J. Martínez-Noguera, Linda H. Chung and Pedro E. Alcaraz

0.2 −0.8 0.4  Fat max 48.8 7.8 47.4 6.8 0.17 .470 −1.4 −5.4 −2.6  %Fat fatmax 35.5 19.6 43.1 16.1 0.36 .171 7.5 −3.5 18.6 Threshold group  MFO, g/min 0.44 0.17 0.50 0.24 0.56 .404 0.6 −0.8 0.2  MFO FFM , mg/kg/min 7.3 2.5 8.0 3.7 0.45 .513 0.8 −1.6 3.1  V MFO 7.2 2.3 8.4 3.7 0.45 .328 1.1 −3.5 1

Restricted access

Ulrika Andersson-Hall, Stefan Pettersson, Fredrik Edin, Anders Pedersen, Daniel Malmodin and Klavs Madsen

.05). Table 1 Data From Incremental Fat Oxidation Tests CON PLA PRO CHO Test 1 Test 2 Test 2 Test 2 Maximal fat oxidation (g·min −1 ) 0.28 ± 0.08 0.57 ± 0.13 1 0.52 ± 0.08 1 0.44 ± 0.12 1,2 Fatmax (% of VO 2max ) 41 ± 7 54 ± 4 1 55 ± 6 1 50 ± 8 1,2,3 RER at fatmax 0.87 ± 0.04 0.80 ± 0.02 1 0.82 ± 0.02 1 0

Restricted access

∶1 glucose-fructose ratio), followed by 60 min distance test. Total oxidation rates were calculated from breath-by-breath V ˙ O 2 and V ˙ CO 2 measurements. Results.— Maximum fat oxidation (Fatmax) during IET was (mean) 68 (95% CI: 61–74)% V ˙ O 2 max. The cessation of fat oxidation (Fatmin) occurred