Evaluation of a graded exercise test to determine peak fat oxidation in individuals with low cardiorespiratory fitness

2018 ◽  
Vol 43 (12) ◽  
pp. 1288-1297 ◽  
Author(s):  
Oliver J. Chrzanowski-Smith ◽  
Robert M. Edinburgh ◽  
James A. Betts ◽  
Keith A. Stokes ◽  
Javier T. Gonzalez
Keyword(s):  
Steady State ◽  
Gas Exchange ◽  
Test Validity ◽  
Endurance Performance ◽  
Fat Oxidation ◽  
Peak Oxygen Consumption ◽  
Intraindividual Variation ◽  
Exercise Tests ◽  
Oxidation Rates ◽  
Ultra Endurance

The maximal capacity to utilise fat (peak fat oxidation, PFO) may have implications for health and ultra-endurance performance and is commonly determined by incremental exercise tests employing 3-min stages. However, 3-min stages may be insufficient to attain steady-state gas kinetics, compromising test validity. We assessed whether 4-min stages produce steady-state gas exchange and reliable PFO estimates in adults with peak oxygen consumption < 40 mL·kg−1·min−1. Fifteen participants (9 females) completed a graded test to determine PFO and the intensity at which this occurred (FATMAX). Three short continuous exercise sessions (SCE) were then completed in a randomised order, involving completion of the graded test to the stage (i) preceding, (ii) equal to (SCEequal), or (iii) after the stage at which PFO was previously attained, whereupon participants then continued to cycle for 10 min at that respective intensity. Expired gases were sampled at minutes 3–4, 5–6, 7–8, and 9–10. Individual data showed steady-state gas exchange was achieved within 4 min during SCEequal. Mean fat oxidation rates were not different across time within SCEequal nor compared with the graded test at FATMAX (both p > 0.05). However, the graded test displayed poor surrogate validity (SCEequal, minutes 3–4 vs. 5–6, 7–8, and 9–10) and day-to-day reliability (minutes 3–4, SCEequal vs. graded test) to determine PFO, as evident by correlations (range: 0.47–0.83) and typical errors and 95% limits of agreement (ranges: 0.03–0.05 and ±0.09–0.15 g·min−1, respectively). In conclusion, intraindividual variation in PFO is substantial despite 4-min stages establishing steady-state gas exchange in individuals with low fitness. Individual assessment of PFO may require multiple assessments.

Higher baseline fat oxidation promotes gynoid fat mobilization in response to a 12-week exercise intervention in sedentary, obese black South African women

2020 ◽  
Vol 45 (3) ◽  
pp. 327-335 ◽  
Author(s):  
Louise D. Clamp ◽  
Amy E. Mendham ◽  
Jacolene Kroff ◽  
Julia H. Goedecke
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
South African ◽  
Fat Mass ◽  
Exercise Intervention ◽  
Fat Oxidation ◽  
Peak Oxygen Consumption ◽  
Black South African ◽  
Oxidation Rates ◽  
Gynoid Fat

This 12-week exercise intervention study assessed changes in cardiorespiratory fitness (CRF), energy expenditure (EE), and substrate utilisation at rest and during exercise in obese, black South African (SA) women and explored associations with changes in body composition. Black SA women (body mass index: 30–40 kg·m−2, age: 20–35 years) were randomised into control (CTL; n = 15, maintaining usual activity) or exercise (EXE; n = 20; 12 weeks, 4 days·week−1, 40–60 min·day−1 at >70% peak heart rate) groups. Pre- and post-intervention testing included peak oxygen consumption, resting and steady state (50% peak oxygen consumption) EE, respiratory exchange, and body composition (dual-energy X-ray absorptiometry). Dietary intake (4-day) and daily step-count (ActivPAL, activPAL3c; PAL Technologies Ltd, Glasgow, UK) was collected at pre-testing and at 4, 8, and 12 weeks. EXE increased peak oxygen consumption (24.9 ± 2.4 to 27.6 ± 3.4 mL·min−1·kg−1; p < 0.001) and steady state fat oxidation rates (7.5 ± 2.5 to 9.0 ± 2.7 mg·min−1·kg−1 fat-free soft tissue mass; p = 0.003) (same relative exercise intensity). CTL remained unchanged (p > 0.05). EXE reduced proportional gynoid fat mass (percentage total fat mass, p = 0.002). Baseline resting carbohydrate oxidation rates (p = 0.036) and steady state fat oxidation rates (p = 0.021) explained 60.6% of the variability in Δgynoid fat mass (p < 0.001) in EXE. This 12-week exercise intervention improved CRF and steady state fat oxidation rates. Greater reliance on fat oxidation at baseline promoted proportional reductions in gynoid, not visceral, fat mass in response to exercise training. Novelty Combined exercise training in obese black South African women increased cardiorespiratory fitness and rates of fat oxidation during steady state exercise. Exercise training reduced proportional gynoid, not visceral, fat, potentially representing an ethnic/sex-specific response. Baseline substrate utilisation (resting and steady state exercise (50% peak oxygen uptake)) predicted changes in gynoid fat mass.

scholarly journals Feeding Tolerance, Glucose Availability, and Whole-Body Total Carbohydrate and Fat Oxidation in Male Endurance and Ultra-Endurance Runners in Response to Prolonged Exercise, Consuming a Habitual Mixed Macronutrient Diet and Carbohydrate Feeding During Exercise

2022 ◽  
Vol 12 ◽  
Author(s):  
Christopher E. Rauch ◽  
Alan J. McCubbin ◽  
Stephanie K. Gaskell ◽  
Ricardo J. S. Costa
Keyword(s):  
Steady State ◽  
Exercise Test ◽  
Fat Oxidation ◽  
Incremental Exercise ◽  
Whole Body ◽  
Oxidation Rates ◽  
Incremental Exercise Test ◽  
Carbohydrate Feeding ◽  
Endurance Runners ◽  
Ultra Endurance

Using metadata from previously published research, this investigation sought to explore: (1) whole-body total carbohydrate and fat oxidation rates of endurance (e.g., half and full marathon) and ultra-endurance runners during an incremental exercise test to volitional exhaustion and steady-state exercise while consuming a mixed macronutrient diet and consuming carbohydrate during steady-state running and (2) feeding tolerance and glucose availability while consuming different carbohydrate regimes during steady-state running. Competitively trained male endurance and ultra-endurance runners (n = 28) consuming a balanced macronutrient diet (57 ± 6% carbohydrate, 21 ± 16% protein, and 22 ± 9% fat) performed an incremental exercise test to exhaustion and one of three 3 h steady-state running protocols involving a carbohydrate feeding regime (76–90 g/h). Indirect calorimetry was used to determine maximum fat oxidation (MFO) in the incremental exercise and carbohydrate and fat oxidation rates during steady-state running. Gastrointestinal symptoms (GIS), breath hydrogen (H2), and blood glucose responses were measured throughout the steady-state running protocols. Despite high variability between participants, high rates of MFO [mean (range): 0.66 (0.22–1.89) g/min], Fatmax [63 (40–94) % V̇O2max], and Fatmin [94 (77–100) % V̇O2max] were observed in the majority of participants in response to the incremental exercise test to volitional exhaustion. Whole-body total fat oxidation rate was 0.8 ± 0.3 g/min at the end of steady-state exercise, with 43% of participants presenting rates of ≥1.0 g/min, despite the state of hyperglycemia above resting homeostatic range [mean (95%CI): 6.9 (6.7–7.2) mmol/L]. In response to the carbohydrate feeding interventions of 90 g/h 2:1 glucose–fructose formulation, 38% of participants showed breath H2 responses indicative of carbohydrate malabsorption. Greater gastrointestinal symptom severity and feeding intolerance was observed with higher carbohydrate intakes (90 vs. 76 g/h) during steady-state exercise and was greatest when high exercise intensity was performed (i.e., performance test). Endurance and ultra-endurance runners can attain relatively high rates of whole-body fat oxidation during exercise in a post-prandial state and with carbohydrate provisions during exercise, despite consuming a mixed macronutrient diet. Higher carbohydrate intake during exercise may lead to greater gastrointestinal symptom severity and feeding intolerance.

scholarly journals Maximal Fat Oxidation is Related to Performance in an Ironman Triathlon

2017 ◽  
Vol 38 (13) ◽  
pp. 975-982 ◽  
Author(s):  
Jacob Frandsen ◽  
Stine Vest ◽  
Steen Larsen ◽  
Flemming Dela ◽  
Jørn Helge
Keyword(s):  
Body Fat ◽  
Oxidation Rate ◽  
Endurance Performance ◽  
Fat Oxidation ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Race Time ◽  
Maximal Fat Oxidation ◽  
Ultra Endurance ◽  
Ironman Triathlon

AbstractThe aim of the present study was to investigate the relationship between maximal fat oxidation rate (MFO) measured during a progressive exercise test on a cycle ergometer and ultra-endurance performance. 61 male ironman athletes (age: 35±1 yrs. [23–47 yrs.], with a BMI of 23.6±0.3 kg/m2 [20.0–30.1 kg/m2], a body fat percentage of 16.7±0.7% [8.4–30.7%] and a VO2peak of 58.7±0.7 ml/min/kg [43.9–72.5 ml/min/kg] SEM [Range]) were tested in the laboratory between 25 and 4 days prior to the ultra-endurance event, 2016 Ironman Copenhagen. Simple bivariate analyses revealed significant negative correlations between race time and MFO (r2=0.12, p<0.005) and VO2peak (r2=0.45, p<0.0001) and a positive correlation between race time and body fat percentage (r2=0.27, p<0.0001). MFO and VO2peak were not correlated. When the significant variables from the bivariate regression analyses were entered into the multiple regression models, VO2peak and MFO together explained 50% of the variation observed in race time among the 61 Ironman athletes (adj R2=0.50, p<0.001). These results suggests that maximal fat oxidation rate exert an independent influence on ultra-endurance performance (>9 h). Furthermore, we demonstrate that 50% of the variation in Ironman triathlon race time can be explained by peak oxygen uptake and maximal fat oxidation.

A single 1-h bout of evening exercise increases basal FFA flux without affecting VLDL-triglyceride and VLDL-apolipoprotein B-100 kinetics in untrained lean men

2007 ◽  
Vol 292 (6) ◽  
pp. E1568-E1574 ◽  
Author(s):  
Faidon Magkos ◽  
Bruce W. Patterson ◽  
B. Selma Mohammed ◽  
Bettina Mittendorfer
Keyword(s):  
Oxygen Consumption ◽  
Apolipoprotein B ◽  
Late Phase ◽  
Fat Oxidation ◽  
Peak Oxygen Consumption ◽  
Whole Body ◽  
Moderate Intensity ◽  
Oxidation Rates ◽  
Tracer Techniques ◽  
Vldl Triglyceride

Our group (Magkos F, Wright DC, Patterson BW, Mohammed BS, Mittendorfer B, Am J Physiol Endocrinol Metab 290: E355–E362, 2006) has recently demonstrated that a single, prolonged bout of moderate-intensity cycling (2 h at 60% of peak oxygen consumption) in the evening increases basal whole-body free fatty acid (FFA) flux and fat oxidation, decreases hepatic VLDL-apolipoprotein B-100 (apoB-100) secretion, and enhances removal efficiency of VLDL-triglyceride (TG) from the circulation the following day in untrained, healthy, lean men. In the present study, we investigated the effect of a single, shorter-duration bout of the same exercise (1 h cycling at 60% of peak oxygen consumption) on basal FFA, VLDL-TG, and VLDL-apoB-100 kinetics in seven untrained, healthy, lean men by using stable isotope-labeled tracer techniques. Basal FFA rate of appearance in plasma and plasma FFA concentration were ∼55% greater ( P < 0.05) the morning after exercise than rest, whereas resting metabolic rate and whole-body substrate oxidation rates were not different after rest and exercise. Exercise had no effect on plasma VLDL-TG and VLDL-apoB-100 concentrations, hepatic VLDL-TG and VLDL-apoB-100 secretion rates, and VLDL-TG and VLDL-apoB-100 plasma clearance rates (all P > 0.05). We conclude that in untrained, healthy, lean men 1) the exercise-induced changes in basal whole-body fat oxidation, VLDL-TG, and VLDL-apoB-100 metabolism during the late phase of recovery from exercise are related to the duration of the exercise bout; 2) single sessions of typical recreational activities appear to have little effect on basal, fasting plasma TG homeostasis; and 3) there is a dissociation between systemic FFA availability and VLDL-TG and VLDL-apoB-100 secretion by the liver.

The Effect of Acute Taurine Ingestion on Endurance Performance and Metabolism in Well-Trained Cyclists

2010 ◽  
Vol 20 (4) ◽  
pp. 322-329 ◽  
Author(s):  
Jane A. Rutherford ◽  
Lawrence L. Spriet ◽  
Trent Stellingwerff
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Endurance Performance ◽  
Fat Oxidation ◽  
Whole Body ◽  
Oxidation Rates ◽  
Acute Ingestion ◽  
Exercise Period ◽  
Expired Gas ◽  
Total Fat

This study examined whether acute taurine (T) ingestion before prolonged cycling would improve time-trial (TT) performance and alter whole-body fuel utilization compared with a control (CON) trial and a placebo (PL) trial in which participants were told they received taurine but did not. Eleven endurance-trained male cyclists (27.2 ± 1.5 yr, 74.3 ± 2.3 kg, 59.9 ± 2.3 ml · kg−1 · min−1; M ± SEM) completed 3 trials in a randomized, crossover, blinded design in which they consumed a noncaloric sweetened beverage with either 1.66 g of T or nothing added (CON, PL) 1 hr before exercise. Participants then cycled at 66.5% ± 1.9% VO2max for 90 min followed immediately by a TT (doing 5 kJ of work/kg body mass as fast as possible). Data on fluid administration, expired gas, heart rate, and ratings of perceived exertion were collected at 15-min intervals during the 90-min cycling ride, but there were no differences recorded between trials. There was no difference in TT performance between any of the 3 trials (1,500 ± 87 s). Average carbohydrate (T 2.73 ± 0.21, CON 2.88 ± 0.19, PL 2.89 ± 0.20 g/min) and fat (T 0.45 ± 0.05, CON 0.39 ± 0.04, PL 0.39 ± 0.05 g/min) oxidation rates were unaffected by T supplementation. T ingestion resulted in a 16% increase (5 g, ~84 kJ; p < .05) in total fat oxidation over the 90-min exercise period compared with CON and PL. The acute ingestion of 1.66 g of T before exercise did not enhance TT performance but did result in a small but significant increase in fat oxidation during submaximal cycling in endurance-trained cyclists.

Effects of Varying the Step Duration on the Determination of Lactate Thresholds in Elite Rowers

2018 ◽  
Vol 13 (6) ◽  
pp. 687-693 ◽  
Author(s):  
Pitre C. Bourdon ◽  
Sarah M. Woolford ◽  
Jonathan D. Buckley
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
Lactate Threshold ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Peak Oxygen Consumption ◽  
Maximal Lactate Steady State ◽  
Exercise Tests ◽  
Step Duration ◽  
Elite Rowers

This study aimed to identify the minimum increment duration required to accurately assess 2 distinct lactate thresholds. A total of 21 elite rowers (12 women and 9 men) participated in this study, and each performed 8 or 9 rowing tests comprising 5 progressive incremental tests (3-, 4-, 5-, 7-, or 10-min steps) and at least three 30-min constant-intensity maximal lactate steady-state assessments. Power output (PO) at lactate threshold 1 was higher in the 3- and 4-min incremental tests. No other measures were different for lactate threshold 1. The PO at the second lactate threshold was different between most tests and was higher than the PO at maximal lactate steady state, except for the 10-min incremental test. Lactate threshold 2 oxygen consumption was higher in the 3-, 4-, and 5-min tests, but heart rate (HR) and rating of perceived exertion were not different between tests. Peak PO in the incremental tests was inversely related to the step durations (r2 = .86, P ≤ .02). Peak oxygen consumption was higher in the shorter (≤5 min) than the longer (≥7 min) incremental tests, whereas peak HR was not different between tests. These data suggest that for the methods used in this study, incremental exercise tests with step durations ≤7 min overestimate maximal lactate steady-state exercise intensity, peak physiological values are best determined using incremental tests with step durations ≤4 min, and HR measures are not affected by step duration, and therefore, prescription of training HRs can be made using any of these tests.

Determinants of Peak Fat Oxidation Rates During Cycling in Healthy Men and Women

2021 ◽  
Vol 31 (3) ◽  
pp. 227-235
Author(s):  
Oliver J. Chrzanowski-Smith ◽  
Robert M. Edinburgh ◽  
Mark P. Thomas ◽  
Aaron Hengist ◽  
Sean Williams ◽  
...  
Keyword(s):  
Physical Activity ◽  
Fat Mass ◽  
Oxidation Rate ◽  
Fat Oxidation ◽  
Activity Level ◽  
Habitual Physical Activity ◽  
Fat Free Mass ◽  
Peak Oxygen Consumption ◽  
Oxidation Rates ◽  
Positive Coefficients

This study explored lifestyle and biological determinants of peak fat oxidation (PFO) during cycle ergometry, using duplicate measures to account for day-to-day variation. Seventy-three healthy adults (age range: 19–63 years; peak oxygen consumption ; n = 32 women]) completed trials 7–28 days apart that assessed resting metabolic rate, a resting venous blood sample, and PFO by indirect calorimetry during an incremental cycling test. Habitual physical activity (combined heart rate accelerometer) and dietary intake (weighed record) were assessed before the first trial. Body composition was assessed 2–7 days after the second identical trial by dual-energy X-ray absorptiometry scan. Multiple linear regressions were performed to identify determinants of PFO (mean of two cycle tests). A total variance of 79% in absolute PFO (g·min−1) was explained with positive coefficients for (strongest predictor), FATmax (i.e the % of that PFO occurred at), and resting fat oxidation rate (g·min−1), and negative coefficients for body fat mass (kg) and habitual physical activity level. When expressed relative to fat-free mass, 64% of variance in PFO was explained: positive coefficients for FATmax (strongest predictor), , and resting fat oxidation rate, and negative coefficients for male sex and fat mass. This duplicate design revealed that biological and lifestyle factors explain a large proportion of variance in PFO during incremental cycling. After accounting for day-to-day variation in PFO, and FATmax were strong and consistent predictors of PFO.

scholarly journals Effects of face masks on performance and cardiorespiratory response in well-trained athletes

2021 ◽  
Author(s):  
Florian Egger ◽  
Dominic Blumenauer ◽  
Patrick Fischer ◽  
Andreas Venhorst ◽  
Saarraaken Kulenthiran ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Minute Ventilation ◽  
Anaerobic Exercise ◽  
Peak Oxygen Consumption ◽  
Exercise Tests ◽  
Maximum Performance ◽  
Outdoor Sports ◽  
Cardiorespiratory Response ◽  
Individual Anaerobic Threshold ◽  
The Individual

Abstract Background During the COVID-19 pandemic, compulsory masks became an integral part of outdoor sports such as jogging in crowded areas (e.g. city parks) as well as indoor sports in gyms and sports centers. This study, therefore, aimed to investigate the effects of medical face masks on performance and cardiorespiratory parameters in athletes. Methods In a randomized, cross-over design, 16 well-trained athletes (age 27 ± 7 years, peak oxygen consumption 56.2 ± 5.6 ml kg−1 min−1, maximum performance 5.1 ± 0.5 Watt kg−1) underwent three stepwise incremental exercise tests to exhaustion without mask (NM), with surgical mask (SM) and FFP2 mask (FFP2). Cardiorespiratory and metabolic responses were monitored by spiroergometry and blood lactate (BLa) testing throughout the tests. Results There was a large effect of masks on performance with a significant reduction of maximum performance with SM (355 ± 41 Watt) and FFP2 (364 ± 43 Watt) compared to NM (377 ± 40 Watt), respectively (p < 0.001; ηp2 = 0.50). A large interaction effect with a reduction of both oxygen consumption (p < 0.001; ηp2 = 0.34) and minute ventilation (p < 0.001; ηp2 = 0.39) was observed. At the termination of the test with SM 11 of 16 subjects reported acute dyspnea from the suction of the wet and deformed mask. No difference in performance was observed at the individual anaerobic threshold (p = 0.90). Conclusion Both SM and to a lesser extent FFP2 were associated with reduced maximum performance, minute ventilation, and oxygen consumption. For strenuous anaerobic exercise, an FFP2 mask may be preferred over an SM.

The Effect of Nutritional Manipulation on Ultra-Endurance Performance: A Case Study

2005 ◽  
Vol 13 (3) ◽  
pp. 199-215 ◽  
Author(s):  
Anna L. Robins ◽  
Don M. Davies ◽  
Gareth E. Jones
Keyword(s):  
Endurance Performance ◽  
Ultra Endurance

Substrate oxidation during exercise in taekwondo athletes: impact of aerobic fitness status

2020 ◽  
Vol 16 (5) ◽  
pp. 371-376
Author(s):  
B. Taati ◽  
H. Rohani
Keyword(s):  
Aerobic Fitness ◽  
Oxidation Rate ◽  
Fat Oxidation ◽  
Potential Effect ◽  
Substrate Oxidation ◽  
Training Experience ◽  
Male Athletes ◽  
Fitness Level ◽  
Oxidation Rates ◽  
Maximal Fat Oxidation

The present study aimed to investigate the potential effect of different aerobic fitness levels on substrate oxidation in trained taekwondo athletes. 57 male athletes (age 21.10±7.79 years; VO2max 50.67±6.67 ml/kg/min) with regular weekly taekwondo training and training experience of at least three years completed a graded exercise test to exhaustion on a treadmill. Maximal fat oxidation (MFO), the exercise intensity related to MFO (Fatmax), and carbohydrate (CHO) oxidation rate were measured using indirect calorimetry methods. The athletes then were divided into a low (<50 ml/kg/min, n=18) and high (>50 ml/kg/min, n=39) VO2max group. The average MFO was higher in the high VO2max group than in the low VO2max group (0.46±0.19 vs 0.28±0.11 g/min; P<0.001). Although Fatmax tended toward higher values in the high VO2max group, no difference was observed between the groups (49.15±15.22 vs 42.42±12.37% of VO2max; P=0.18). It was also shown that the high VO2max group had a lower CHO oxidation rate and a higher fat oxidation rate at given exercise intensities. In conclusion, it seems that MFO and substrate oxidation rates in taekwondo athletes can be influenced by aerobic fitness level such that the athletes with higher VO2max appeared to use more fat as a fuel source for energy supply during a given exercise.

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