scholarly journals β-Hydroxybutyrate Oxidation in Exercise Is Impaired by Low-Carbohydrate and High-Fat Availability

2021 ◽  
Vol 8 ◽  
Author(s):  
David J. Dearlove ◽  
David Holdsworth ◽  
Tom Kirk ◽  
Leanne Hodson ◽  
Evelina Charidemou ◽  
...  

Purpose: In this study, we determined ketone oxidation rates in athletes under metabolic conditions of high and low carbohydrate (CHO) and fat availability.Methods: Six healthy male athletes completed 1 h of bicycle ergometer exercise at 75% maximal power (WMax) on three occasions. Prior to exercise, participants consumed 573 mg·kg bw−1 of a ketone ester (KE) containing a 13C label. To manipulate CHO availability, athletes undertook glycogen depleting exercise followed by isocaloric high-CHO or very-low-CHO diets. To manipulate fat availability, participants were given a continuous infusion of lipid during two visits. Using stable isotope methodology, β-hydroxybutyrate (βHB) oxidation rates were therefore investigated under the following metabolic conditions: (i) high CHO + normal fat (KE+CHO); (ii) high CHO + high fat KE+CHO+FAT); and (iii) low CHO + high fat (KE+FAT).Results: Pre-exercise intramuscular glycogen (IMGLY) was approximately halved in the KE+FAT vs. KE+CHO and KE+CHO+FAT conditions (both p < 0.05). Blood free fatty acids (FFA) and intramuscular long-chain acylcarnitines were significantly greater in the KE+FAT vs. other conditions and in the KE+CHO+FAT vs. KE+CHO conditions before exercise. Following ingestion of the 13C labeled KE, blood βHB levels increased to ≈4.5 mM before exercise in all conditions. βHB oxidation was modestly greater in the KE+CHO vs. KE+FAT conditions (mean diff. = 0.09 g·min−1, p = 0.03; d = 0.3), tended to be greater in the KE+CHO+FAT vs. KE+FAT conditions (mean diff. = 0.07 g·min−1; p = 0.1; d = 0.3) and were the same in the KE+CHO vs. KE+CHO+FAT conditions (p < 0.05; d < 0.1). A moderate positive correlation between pre-exercise IMGLY and βHB oxidation rates during exercise was present (p = 0.04; r = 0.5). Post-exercise intramuscular βHB abundance was markedly elevated in the KE+FAT vs. KE+CHO and KE+CHO+FAT conditions (both, p < 0.001; d = 2.3).Conclusion: βHB oxidation rates during exercise are modestly impaired by low CHO availability, independent of circulating βHB levels.

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2496 ◽  
Author(s):  
Emily E. Howard ◽  
Lee M. Margolis

Interest in low-carbohydrate, high-fat (LCHF) diets has increased over recent decades given the theorized benefit of associated intramuscular adaptations and shifts in fuel utilization on endurance exercise performance. Consuming a LCHF diet during exercise training increases the availability of fat (i.e., intramuscular triglyceride stores; plasma free fatty acids) and decreases muscle glycogen stores. These changes in substrate availability increase reliance on fat oxidation for energy production while simultaneously decreasing reliance on carbohydrate oxidation for fuel during submaximal exercise. LCHF diet-mediated changes in substrate oxidation remain even after endogenous or exogenous carbohydrate availability is increased, suggesting that the adaptive response driving changes in fat and carbohydrate oxidation lies within the muscle and persists even when the macronutrient content of the diet is altered. This narrative review explores the intramuscular adaptations underlying increases in fat oxidation and decreases in carbohydrate oxidation with LCHF feeding. The possible effects of LCHF diets on protein metabolism and post-exercise muscle remodeling are also considered.


Nutrients ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1339 ◽  
Author(s):  
Qingyi Huang ◽  
Sihui Ma ◽  
Takaki Tominaga ◽  
Katsuhiko Suzuki ◽  
Chunhong Liu

A low-carbohydrate, high-fat ketogenic diet (KD) is a nutritional approach ensuring that the body utilizes lipids. In our previous study, we found that an eight-week ketogenic high-fat, low-carbohydrate diet increased the capacity of endurance exercise in mice without aggravated muscle injury, despite the decrease of absolute muscle volume. The potential mechanism is most possibly to be enhanced capacity to mobilize and utilize fat. In the present study, we investigated whether a ketogenic diet influences post-exercise recovery by measuring blood biomarkers, muscle and liver oxidative state as well as fatigue recovery 24 h post exercise by employing an open-field locomotion test. Several biochemistry markers indicating exercise-induced injury after exhaustive exercise were improved by KD, followed by a 24-h rest with free feed access, including lactate. No aggravated hepatic oxidative damage was observed, whereas muscular oxidative stress was increased by KD. Accelerated recovery induced by exhaustive exercise was also observed from blood biomarkers of injury. For fatigue recovery, lactate concentration, a marker often employed as exhaustion index was lowered by KD, whereas an open field test showed that KD application contributed to increased locomotion after exhaustive exercise, followed by a 24-h rest. These results suggest that KD has the potential to be used as a fatigue-preventing and/or recovery-promoting diet approach in endurance athletes.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 723-P
Author(s):  
LINGWANG AN ◽  
DANDAN WANG ◽  
XIAORONG SHI ◽  
CHENHUI LIU ◽  
KUEICHUN YEH ◽  
...  

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1944
Author(s):  
Parker N. Hyde ◽  
Teryn N. Sapper ◽  
Richard A. LaFountain ◽  
Madison L. Kackley ◽  
Alex Buga ◽  
...  

Background. Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. Objective. We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. Methods. We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based ‘Run-In’ diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. Results. Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. Conclusions. These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.


2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Madis Jaagura ◽  
Ene Viiard ◽  
Kätrin Karu‐Lavits ◽  
Kaarel Adamberg

2020 ◽  
Vol 16 (5) ◽  
pp. 371-376
Author(s):  
B. Taati ◽  
H. Rohani

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.


1989 ◽  
Vol 66 (6) ◽  
pp. 2710-2716 ◽  
Author(s):  
J. Chwalbinska-Moneta ◽  
R. A. Robergs ◽  
D. L. Costill ◽  
W. J. Fink

The purpose of this study was to investigate the relationship between muscle and blood lactate concentrations during progressive exercise. Seven endurance-trained male college students performed three incremental bicycle ergometer exercise tests. The first two tests (tests I and II) were identical and consisted of 3-min stage durations with 2-min rest intervals and increased by 50-W increments until exhaustion. During these tests, blood was sampled from a hyperemized earlobe for lactate and pH measurement (and from an antecubital vein during test I), and the exercise intensities corresponding to the lactate threshold (LT), individual anaerobic threshold (IAT), and onset of blood lactate accumulation (OBLA) were determined. The test III was performed at predetermined work loads (50 W below OBLA, at OBLA, and 50 W above OBLA), with the same stage and rest interval durations of tests I and II. Muscle biopsies for lactate and pH determination were taken at rest and immediately after the completion of the three exercise intensities. Blood samples were drawn simultaneously with each biopsy. Muscle lactate concentrations increased abruptly at exercise intensities greater than the “below-OBLA” stage [50.5% maximal O2 uptake (VO2 max)] and resembled a threshold. An increase in blood lactate and [H+] also occurred at the below-OBLA stage; however, no significant change in muscle [H+] was observed. Muscle lactate concentrations were highly correlated to blood lactate (r = 0.91), and muscle-to-blood lactate ratios at below-OBLA, at-OBLA, and above-OBLA stages were 0.74, 0.63, 0.96, and 0.95, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


1994 ◽  
Vol 76 (6) ◽  
pp. 2570-2577 ◽  
Author(s):  
C. K. Sen ◽  
T. Rankinen ◽  
S. Vaisanen ◽  
R. Rauramaa

The association between exercise intensity and related oxidative stress was investigated in nine men who exercised for 30 min at their aerobic (AeT) and anaerobic (AnaeT) thresholds. We also tested the effect of oral N-acetylcysteine (NAC) on exercise-associated rapid blood glutathione (GSH) oxidation in subjects performing two identical maximal bicycle ergometer exercise (Max) tests. Before the second test (Max with NAC supplementation [Max(NAC)]), the men took 200 x 4 mg/day of NAC tablets for 2 days and an additional 800 mg on the test morning. Blood samples were drawn before, immediately after, and 24 h after the tests. Total and oxidized GSH levels in blood were determined. Plasma thiobarbituric acid-reactive substances and net peroxyl radical scavenging capacity (PSC) were assayed. Exercise-associated damage in leukocyte DNA was estimated by fluorometric analysis of DNA unwinding. A single bout of exercise at Max, AeT, and AnaeT resulted in a significant increase in blood GSH oxidation but did not influence net PSC of plasma. Although an association between a single bout of exercise and leukocyte DNA damage was apparent, this study suggests that the parameter may not serve as a sensitive index to assess the role of exercise intensity in the extent of exercise-associated oxidative stress. Plasma thiobarbituric acid-reactive substances did not change after either Max or Max(NAC) tests. NAC supplementation resulted in an increase in preexercise PSC, indicating a higher net antioxidant capacity of the plasma, but did not affect blood GSH.(ABSTRACT TRUNCATED AT 250 WORDS)


1999 ◽  
Vol 87 (3) ◽  
pp. 947-954 ◽  
Author(s):  
Kathleen J. Melanson ◽  
Margriet S. Westerterp-Plantenga ◽  
L. Arthur Campfield ◽  
Wim H. M. Saris

Regulatory functions of glycogen stores and blood glucose on human appetite, particularly relating to exercise, are not fully understood. Ten men (age 20–31 yr) performed glycogen-depleting exercise in an evening, ate a low-carbohydrate dinner, and stayed overnight in the laboratory. The next day, blood glucose was monitored continuously for 517 ± 23 (SE) min. Subjects had access to high-fat and high-carbohydrate foods after baseline glucose and respiratory quotient were determined. In the afternoon, 1 h of moderate exercise was performed. Baseline respiratory quotient was 0.748 ± 0.008, plasma free fatty acids were 677 ± 123 μmol/l, insulin was 4.8 ± 0.5 μU/ml, and leptin was 1.9 ± 0.3 ng/ml. Postabsorptively, 8 of 10 meals were initiated during stability in blood glucose. Postprandially, the association between meal initiation and blood glucose declines became significant (χ2 = 7.82). During moderate exercise, blood glucose initially decreased but recovered before completion. When the glycogen buffer is depleted, meal initiation can occur during blood glucose stability; the relationship between blood glucose declines and meal initiation reestablishes with refeeding.


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