Fat Oxidation Rate Research Articles

Effects of the Aerobic Exercise Types of the Same Amount of Exercise on the Energy Metabolism During Exercise and Recovery Phase

OBJECTIVES The purpose of this study was to investigate the effects of aerobic exercise types on energy metabolism during and after exercise under the same exercise volume conditions.METHODS Ten healthy men were randomly assigned to interval(IV), intermittent(IM), and continuous(CO) exercise, and the experiment was conducted at intervals of one week and consumed 300 kcal. The data were verified by repeated measurement one-way ANOVA, and contrast was conducted. The statistical significance level was set at α=0.05.RESULTS As a result of the study, first, among the energy metabolism variables during exercise, oxygen intake(VO2) was statistically significantly higher in the IM and CO exercise than in the IV exercise(p<0.001). The respiratory exchange rate(RER, p<0.001), energy consumption per minute(ECM, p<0.001), and carbohydrate consumption amount(CCA, p=0.013) were significantly higher in the IM exercise, but there was no statistically significant difference in the fat oxidation rate(FOR), fat consumption amount(FCA), and carbohydrate consumption rate(CCR). Second, there were statistically significant differences in EPOC(p<0.001), RER(p<0.001), and ECM(p<0.001) in the post-exercise recovery phase, among them, the highest in the IM exercise. In terms of FOR(p=0.002) and FCA(p=0.007), IV and CO exercise were significantly higher than IM exercise, and on the contrary, in terms of CCR(p=0.002) and CCA(p<0.001), IM exercise was higher than IV and CC exercise.CONCLUSIONS In conclusion, considering not only during exercise but also the recovery period after exercise, the intermittent exercise seems to have an advantage in increasing energy consumption while having a shorter exercise time than the other two under the condition of the same exercise amount.

The Effect of Pre-Exercise Caffeine and Glucose Ingestion on Endurance Capacity in Hypoxia: A Double-Blind Crossover Trial.

The impact of caffeine and glucose supplementation in a hypoxic environment on endurance exercise performance remains inconclusive. The current study examined the effect of pre-exercise carbohydrate and caffeine supplementation on endurance exercise performance in an acute hypoxic environment. Eight healthy active young males participated in this double-blind, within-subjects crossover study. Participants ingested the test drink 60 min before exercising at 50% Wmax for 90 min on a cycle ergometer (fatiguing preload); there followed an endurance performance test at 85% Wmax until exhaustion in a hypoxic chamber (~15%O2). Participants completed four experimental trials in a randomized order: caffeine (6 mg·kg-1; Caff), glucose (1 g·kg-1; CHO), caffeine (6 mg·kg-1) + glucose (1 g·kg-1; Caff-CHO), and taste- and color-matched placebo with no caffeine or CHO (PLA). Blood samples were collected during fasting, pre-exercise, every 30 min throughout the exercise, and immediately after exhaustion. The caffeine and glucose trials significantly enhanced endurance capacity in hypoxic conditions by Caff, 44% (68.8-31.5%, 95% confidence interval), CHO, 31% (44.7-15.6%), and Caff-CHO, 46% (79.1-13.2%). Plasma-free fatty-acid and glycerol concentrations were higher in Caff and PLA than in CHO and Caff-CHO (p < 0.05). The estimated rate of fat oxidation was higher in Caff and PLA than in CHO and Caff-CHO (p < 0.05). There were no significant differences in ratings of perceived exertion between trials. In conclusion, the ingestion of caffeine, glucose, or caffeine + glucose one hour before exercising in hypoxic conditions significantly improved 85% Wmax endurance performance after prolonged exercise.

The Rate of Leg Fat Oxidation Is Not Attenuated During Incremental Intensity One-Leg Knee Extensor Exercise.

It is not clear if fat oxidation is attenuated at higher exercise intensities, when exercising with a small muscle mass, and therefore, we studied leg fat oxidation during graded one-leg exercise. Ten males (age: 27 ± 2 years, body mass: 82 ± 3 kg, BMI: 24 ± 1 kg m-2, V̇O2max: 49 ± 2 mL min-1 kg-1) performed one-leg exercise at 25% of maximal workload (Wmax) for 30 min, followed by 120-min exercise at 55% Wmax with the contralateral leg, and finally 30-min exercise at 85% Wmax with the first leg. Blood was sampled from an artery and both femoral veins, and blood flow was determined using Doppler ultrasound. Muscle biopsies were obtained before and after 30 min at each workload. One-way RM ANOVA was applied to determine the impact of exercise intensity. Data are expressed as mean ± SEM. From rest through exercise average blood flow (0.4 ± 0.1, 2.1 ± 0.1, 2.6 ± 0.2, 3.7 ± 0.2 L min-1) and oxygen uptake across the leg (0.03 ± 0.01, 0.23 ± 0.02, 0.35 ± 0.03, 0.53 ± 0.04 L min-1) increased with exercise intensity (p < 0.001). Leg RQ (0.76 ± 0.04, 0.86 ± 0.02,0.87 ± 0.01, 0.92 ± 0.01, p < 0.001), leg plasma FA uptake (2 ± 2, 46 ± 8,83 ± 9, 114 ± 16 μmol min-1; p < 0.001) and rate of leg fat oxidation (0.016 ± 0.005, 0.062 ± 0.012, 0.075 ± 0.011, 0.084 ± 0.018 g min-1, p < 0.007) increased with exercise intensity. Muscle-free carnitine content was unchanged from rest at 25% Wmax and decreased after 30 min exercise at 55% and 85% Wmax (17.4 ± 1.6, 16.6 ± 0.7, 14.5 ± 1.2, 10.5 ± 1.0 mmol/kg dry muscle, respectively; p < 0.006). During incremental one-leg exercise, the rate of leg fat oxidation was not attenuated with increasing exercise intensity, probably due to an insufficient muscle metabolic stress response.

The acute effect of time-restricted feeding (12 & 16 h) and varying exercise intensities on fat-oxidation rate in inactive young adults – a randomized control trial

Background and purposeTime-restricted feeding (TRF) is a dietary pattern that alternates between periods of fasting and feeding, which has gained significant attention in recent years. The 16/8 approach consists of fasting for 16 h and feeding for an 8-h window, while the 12/12 method consists of fasting for 12 h and a 12-h feeding window. Limited research exists comparing the effects of these methods coupled with physical activity (PA). The aim of this investigation was to examine the acute effects between conditions of varying TRF durations (12 and 16 h) and PA intensities on the fat oxidation rate (FOR). It was hypothesized that i) the TRF16 conditions would exhibit higher FORmax and that PA would enhance these effects, and ii) High Intensity Interval Training (HIIT) would result in greater effects on FORmax compared to Low-Moderate Intensity Steady State Continuous Training (MICT) PA.Methods and resultsEighteen young adults (age: 23 ± 2.0 yrs., body mass index: 23.5 ± 2.8 kg·m−2) were recruited and participated in the supervised intervention. The discrete component open circuit spirometry system was used to measure oxygen consumption (VO2), and Frayne’s equation was used to determine the FOR plus FORmax. ANOVA was used to determine pre/post-intervention differences in FORmax. The FORmax for the TRF16 + HIIT intervention was significantly higher than the TRF12 (mean difference = 0.099 g·min-1, p = 0.011, 95% CI 0.017 to 0.180) and TRF16 fast alone (mean difference = 0.093 g·min-1, p = 0.002, 95% CI 0.027 to 0.159). The FORmax for TRF12 + HIIT intervention was significantly higher than the TRF12 fast alone (mean difference = 0.070 g·min−1, p = 0.023, 95% CI 0.007 to 0.134). The TRF16 + HIIT intervention was also significantly higher than the TRF12 fast alone (mean difference = 0.099 g·min−1, p = 0.011, 95% CI 0.017 to 0.180).ConclusionThis study contributes to the ever-growing body of literature on the acute effects of TRF and PA on young adult males and females. The findings suggest that the TRF16 + HIIT PA intervention results in the highest FORmax. Trial registrationRetrospective Registration ISRCTN # 10076373 (October 6, 2023).

The Chemical Quality of Beef Se'i with Different Marination Length Using Evaporated Rosela (Hibiscus sabdariffa Linn) Extract

Experiment was conducted to determine the effect of marination length of beef se’i with the added of evaporated rosela extract (Hibiscus sabdariffa Linn). The completly randomized design (CRD) with 4 treatments and 4 replication was applied in this experiment. Those treatments were P0 marination length of 12 hours without roselle extract; P1 marination length 6 hours with 5% roselle extract; P2 marination length 12 hours with 5% roselle extract, and P3 marination length 18 hours with 5% roselle extract. The parameters measured were fat content, fat oxidation and antioxidant activity. Data compilled were analyzed using variance analysis and Duncan’s further test. The result of analysis showed that the addition of roselle extract had significant effect (P&lt;0.05) on antioxidant Activity but no significant effect (P&gt;0.05) on fat content and fat oxidation. The use of 5% roselle extract with a marination time of 6 to 18 hours tends to reduce fat content, slow down the rate of fat oxidation and strengthen antioxidant activity, suggesting that roselle extract is likely to extend the shelf life of beef se’i. It was concluded that the addition of 5% evaporated roselle extract followed by marination for 6 to 18 hours is likely to result in a longer shelf life of sei.

Influence of the CYP1A2 c.-163A > C polymorphism in the effect of caffeine on fat oxidation during exercise: a pilot randomized, double-blind, crossover, placebo-controlled trial.

The aim of this study was to determine the influence of the CYP1A2 c.-163A > C (rs762551) polymorphism on the effect of oral caffeine intake on fat oxidation during exercise. Using a pilot randomized, double-blind, crossover, placebo-controlled trial, 32 young and healthy individuals (women = 14, men = 18) performed an incremental test on a cycle ergometer with 3-min stages at workloads from 30 to 70% of maximal oxygen uptake (VO2max). Participants performed this test after the ingestion of (a) placebo; (b) 3mg/kg of caffeine; (c) 6mg/kg of caffeine. Fat oxidation rate during exercise was measured by indirect calorimetry. The influence of the CYP1A2 c.-163A > C polymorphism in the effect of caffeine on fat oxidation rates during exercise was established with a three-way ANOVA (substance × genotype × intensity). Eight participants were genotyped as AA, 18 participants were CA heterozygotes, and 6 participants were CC. There was a main effect of substance (F = 3.348, p = 0.050) on fat oxidation rates during exercise with no genotype effect (F = 0.158, p = 0.959). The post hoc analysis revealed that, in comparison to the placebo, 3 and 6mg/kg of caffeine increased fat oxidation at 40-50% VO2max in AA (all p < 0.050) and 50-60% VO2max in CA and CC participants (all p < 0.050). Oral intake of 3 and 6mg/kg of caffeine increased fat oxidation rate during aerobic exercise in individuals with AA, CA and CC genotypes. This suggests that the effect of caffeine to enhance fat oxidation during exercise is not influenced by the CYP1A2 c.-163A > C polymorphism. The study was registered on clinicaltrials.gov with ID: NCT05975489.

The impact of short-term eucaloric low- and high-carbohydrate diets on liver triacylglycerol content in males with overweight and obesity: a randomized crossover study

BackgroundIntrahepatic triacylglycerol (liver TG) content is associated with hepatic insulin resistance and dyslipidemia. Liver TG content can be modulated within days under hypocaloric conditions. ObjectivesWe hypothesized that 4 d of eucaloric low-carbohydrate/high-fat (LC) intake would decrease liver TG content, whereas a high-carbohydrate/low-fat (HC) intake would increase liver TG content, and further that alterations in liver TG would be linked to dynamic changes in hepatic glucose and lipid metabolism. MethodsA randomized crossover trial in males with 4 d + 4 d of LC and HC, respectively, with ≥2 wk of washout. 1H-magnetic resonance spectroscopy (1H-MRS) was used to measure liver TG content, with metabolic testing before and after intake of an LC diet (11E% carbohydrate corresponding to 102 ± 12 {mean ± standard deviation [SD]) g/d, 70E% fat} and an HC diet (65E% carbohydrate corresponding to 537 ± 56 g/d, 16E% fat). Stable [6,6-2H2]-glucose and [1,1,2,3,3-D5]-glycerol tracer infusions combined with hyperinsulinemic-euglycemic clamps and indirect calorimetry were used to measure rates of hepatic glucose production and lipolysis, whole-body insulin sensitivity and substrate oxidation. ResultsEleven normoglycemic males with overweight or obesity (BMI 31.6 ± 3.7 kg/m2) completed both diets. The LC diet reduced liver TG content by 35.3% (95% confidence interval: −46.6, −24.1) from 4.9% [2.4–11.0] (median interquartile range) to 2.9% [1.4–6.9], whereas there was no change after the HC diet. After the LC diet, fasting whole-body fat oxidation and plasma beta-hydroxybutyrate concentration increased, whereas markers of de novo lipogenesis (DNL) diminished. Fasting plasma TG and insulin concentrations were lowered and the hepatic insulin sensitivity index increased after LC. Peripheral glucose disposal was unchanged. ConclusionsReduced carbohydrate and increased fat intake for 4 d induced a marked reduction in liver TG content and increased hepatic insulin sensitivity. Increased rates of fat oxidation and ketogenesis combined with lower rates of DNL are suggested to be responsible for lowering liver TG. This trial was registered at clinicaltrials.gov as NCT04581421.

Different coating application methods: Zein-based edible coating containing Heracleum persicum essential oil for shelf-life enhancement of whey-less cheese.

In this research, the efficiency of brushing (Br), dipping (Di), spraying (S), and enrobing (En) methods was compared in three concentrations of 10%, 15%, and 20% of corn zein (Z) edible coating containing 0.5% of Heracleum persicum essential oil (HEO) in the shelf-life improvement of whey-less cheese during 56 days of cold storage. The results of the photography and colorimetric (L*, a*, and b* parameters) of the samples showed that the En method in 20% of Z created a uniform, brilliant, and attractive surface on the cheese pieces compared to the other groups during the storage period, and the S, Br, and Di methods were in the next categories, respectively. The findings of the texture analysis of the samples showed that all of the treatments significantly (p ≤ .05) preserved the hardness of the cheese samples compared to the control group, and the En method containing Z 20% and HEO was the most effective treatment in preventing the hardness loss of the samples during the 56-day storage period. In all treatments, the growth of aerobic mesophilic bacteria, psychrotrophic bacteria, enterobacteriaceae, molds, and yeasts was significantly (p ≤ .05) reduced in comparison with the control sample, and the En method containing HEO and Z 20% was the most efficient in preventing the microbial growth. The rate of moisture loss, fat oxidation, and pH values of the studied samples significantly (p ≤ .05) decreased in the coated treatments containing a higher concentration of Z and HEO compared with other treatments during the storage period. According to the findings of this study, it can be concluded that the En technique containing Z20% and HEO0.5% was the most effective treatment in the shelf-life improvement of whey-less cheese during 56 days of the refrigerated storage period, and the S, Br, and Di methods were in the next ranks, respectively.

Timing matters: diurnal variation of maximal fat oxidation and substrate oxidation rates in metabolic syndrome-a randomized crossover study.

The aim of this study was to investigate if diurnal oscillation in maximal fat oxidation (MFO) and substrate oxidation rates during exercise exists in subjects with metabolic syndrome (MetS). In a randomized crossover design, 14 MetS patients were assigned to two graded exercise tests conditions performed in the morning (between 7:00 and 9:00 a.m) and in the afternoon (between 4:00 and 5:00 p.m). MFO was defined as the highest absolute value of fat oxidation obtained from the average of last 2-min stages during an indirect calorimetry test. MFO increased by 20.6% from morning to afternoon (p = 0.0002, Cohen's d = 0.52). There was a significant time of day, (p < 0.0001, η2p = 0.76) and intensity effect (p = 0.002, η2p = 0.32) in fat oxidation (Fatox) rates indicating that Fatox was higher in the afternoon than in the morning. Our study extends previous findings on the existence of diurnal variation in maximal fat oxidation to MetS patients, highlighting the afternoon as a more favorable time for fat utilization during exercise. These findings have practical implications for optimizing training timing in MetS patients. PACTR202306776991260.

Impact of date-based energy bar intake on postprandial appetite, metabolism and thermogenesis

Research studies suggest that date-palm (Phoenix dactylifera L.) fruits provide a superior nutritional and health benefits, compared to other fruits (1). They are rich source of many essential nutrients including carbohydrates, dietary fibre, vitamins, minerals, phytochemicals, and antioxidants. The date palm fruits are produced in many countries around the world and about 10-15% of the total production is lost or sold extremely at low prices (2, 3). Despite these, date fruits have been rarely used as an ingredient in commercially available energy bars. The aim of this study is to investigate the impact of newly formulated date-based energy bar (DBEB) (4) intake on subjective appetite, postprandial metabolism, energy substrate oxidation and diet-induced thermogenesis (DIT).Twenty-seven healthy male adults (mean ± SD, aged 20.8 ± 3.5 years with body weight of 66 ± 8 kg) participated in a randomised crossover design study. Each participant conducted two experimental arms and was investigated prior to (baseline) and for three-hours after consumption of either a date- based energy bar (DBEB) or an isocaloric and macronutrient matched mixed fruit-based energy bar (FBEB) as control arm. The DBEB contained significantly less fructose and glucose, but more sucrose and fibre than FBEB. Both experimental arms involved blood sampling, subjective appetite, and indirect calorimetry measurements. At the end of each experiment, an ad libitum buffet meal was provided. Data analysis used descriptive statistics, paired t-test, and two-way ANOVA.Time-averaged composite appetite and satiety scores were not significantly different between control (FBEB) and DBEB arms. Energy intake during ad libitum buffet was also not different between arms. Metabolic rate measured at baseline and during post-ingestion of the bars were not significantly different between FBEB and DBEB arms (arm effect, P&gt;0.05). Thermic effect of bars calculated as percentage increase in metabolic rate above RMR during whole postprandial duration was (mean ± SE) 9.5 ± 1.6 % in DBEB arm and 8.7 ± 1.3 % in the FBEB arm (arm effect, P&gt;0.05). Rates of carbohydrate and fat oxidation were also not different between the two arms (arm effect, P&gt;0.05) Time-averaged concentrations of blood glucose, insulin and triglycerides were similar between the study arms.The obtained results suggest that energy bars based on dates or mixed fruits produce similar effects on postprandial appetite, fat and carbohydrate oxidation, thermic effect and cardiometabolic risk factors. Date fruits can be used as rich source for carbohydrate and energy. However, future research should investigate the impact of date-based energy bars on antioxidant capacity and other health related markers.

Evaluation of metabolic changes in clinic attendees with therapeutic carbohydrate restriction

Background: Obesity and related metabolic health disorders are major clinical problems that have become increasingly prevalent worldwide.Aim: This before-after study examined the impact of therapeutic carbohydrate restriction (TCR) in managing metabolic health and promoting weight loss in a clinical setting using indirect calorimetry (IC).Setting: Data were collected from medical records obtained from a specialised allied health clinic focusing on metabolic health.Methods: The study analysed retrospective data from 202 overweight or obese participants (77% female, mean age 47.3) who received TCR as part of a behavioural modification programme involving multiple visits where their lifestyle, body composition and respiratory quotient (RQ), a key indicator of fat oxidation were recorded.Results: The study found that TCR improved fat oxidation in 84% of participants at short term visit (around 2 weeks), with an average weight loss of 1.8 kg. At medium term visit (around 12 weeks), 82% of participants maintained an increase in fat oxidation rate, with an average weight loss of 3.9 kg. In addition, among those with recorded body composition and waist circumference, 71% of weight lost was from fat, with an average reduction of 4.9 cm in waist measurements.Conclusion: This real-world study suggests that personalised TCR guided by IC can be an effective strategy for improving metabolic flexibility to help manage excess weight and related co-morbidities in a free-living population. Further research is needed to examine the long-term effects of TCR using this approach.Contribution: The utilisation of IC allows for the examination of individual shifts and improvements in metabolism among patients undergoing TCR.

A Dose-Response Study to Examine Paraxanthine’s Impact on Energy Expenditure, Hunger, Appetite, and Lipolysis

This study investigated if paraxanthine (PX) impacts energy expenditure, lipolysis and perceptual responses. In a randomized, double-blind, placebo-controlled, crossover fashion, 21 adults (13 M, 8 F; 26.0 ± 6.4 years, 174.9 ± 11.5 cm, 81.0 ± 15.7 kg body mass, 26.3 ± 3.4 kg/m2) consumed a placebo (PLA), 100 mg (PX100), 200 mg (PX200), and 300 mg of PX (PX300, enfinity®, Ingenious Ingredients, L.P. Lewisville, TX, USA). Venous blood was collected 0, 30, 60, 90, 120 and 180 min (min) after ingestion and analyzed for glycerol and free fatty acids. Resting hemodynamics, metabolic rate and perceptual indicators of hunger, appetite and anxiety were evaluated. Mixed factorial analysis of variance were used to evaluate changes time within and between groups. Heart rate decreased in PX100 compared to PLA 60 (p = .022) and 180 min (p = .001). Blood pressure did not change. Hunger ratings in PLA increased 30 (p = .05), 60 (p = .04), 90 (p = .02), and 180 min (p = .05) after ingestion when compared to PX200. PX200 increased energy expenditure (all p < .05) when compared to PLA. Rates of fat oxidation tended to increase 90 (p = .056) and 120 min (p = .066) in PX200 compared to PLA. Free fatty acids increased in PX300 compared to PLA (p = .002). Glycerol did not change. Ingestion of PX200 augmented energy expenditure and hunger ratings when compared to PLA without impacting hemodynamics or lipolysis.

Lipolysis and fat oxidation decrease during postprandial lactatemia

Circulating glycerol ([glycerol]) and free fatty acid ([FFA]) concentrations decrease and lactate concentration ([lactate]) increases in response to oral glucose consumption, but the effect of increased [lactate] on the rate of lipolysis is not known. We hypothesized that whole-body lipolytic (i.e., glycerol rate of appearance, Ra) and fat oxidation (FOx) rates would decrease following oral glucose consumption and inversely correlate with an increase in [lactate] above baseline levels (i.e., lactatemia) during both enteric (0–30 min) and systemic (60–120 min) phases of the postprandial lactate shuttle (PLS). Young, healthy men and women (n=15) reported to the lab following a 12-hour overnight fast and had the forearm vein catheterized for primed continuous infusion of [1,1,2,3,3-2H]glycerol. The contralateral hand vein was warmed and catheterized for arterialized blood sampling. After a 90-min equilibration period, participants underwent a 75 g oral glucose tolerance test (OGTT). Glycerol Ra was significantly lower at 5 min (1.92 ± 0.12 μmol·kg−1·min−1) and 30–120 min during the OGTT compared to baseline (2.06 ± 0.12 μmol·kg−1·min−1). [Glycerol] was significantly lower from baseline (69.19 ± 2.50 μM) at 30 min (50.58 ± 3.01 μM) after glucose consumption, then continued to decline thereafter. Similarly, [FFA] was significantly lower from baseline (464.71 ± 27.01 μM) at 30 min (247.14 ± 32.78 μM), then continued to decline. FOx was significantly lower from baseline (0.89 ± 0.05 kcal∙min−1) at 60 min (0.58 ± 0.05 kcal∙min−1) and remained steady from then on. Concurrently, [lactate] increased from baseline (0.59 ± 0.06 mM) and was significantly higher at 5 min (0.71 ± 0.06 mM) after glucose consumption, peaked at 15 min (1.09 ± 0.01 mM), reached a nadir at 30 min, then continued to rise thereafter. There was an overall inverse correlation (r = -0.71, p = 0.07) between glycerol Ra and [lactate] during the OGTT that was also present during the enteric phase (r = -0.45, p = 0.55). Similarly, there was overall an inverse correlation between FOx and [lactate] (r = -0.57, p = 0.17), but it was not present during the enteric phase (r = 0.93, p = 0.07). However, the correlations of both glycerol Ra and FOx with [lactate] approached linearity during the systemic phase (r = 0.99, p = 0.06). The reduction in glycerol Ra at 5 min indicates a rapid decrease in the rate of lipolysis following oral glucose consumption. The correlations suggest that lactatemia may influence both glycerol Ra and FOx by exerting an inhibitory effect, particularly during the systemic phase of the PLS. However, the lag in the decrease in FOx and opposing responses of glycerol Ra and [lactate] at 5 min suggests that lactatemia may have a greater role in inhibiting whole-body lipolysis in the postprandial period. Supported by NIH grant R01 AG059715 to GAB. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Exogenous erythropoietin increases hematological status, fat oxidation, and aerobic performance in males following prolonged strenuous training.

This study investigated the effects of EPO on hemoglobin (Hgb) and hematocrit (Hct), time trial (TT) performance, substrate oxidation, and skeletal muscle phenotype throughout 28 days of strenuous exercise. Eight males completed this longitudinal controlled exercise and feeding study using EPO (50 IU/kg body mass) 3×/week for 28 days. Hgb, Hct, and TT performance were assessed PRE and on Days 7, 14, 21, and 27 of EPO. Rested/fasted muscle obtained PRE and POST EPO were analyzed for gene expression, protein signaling, fiber type, and capillarization. Substrate oxidation and glucose turnover were assessed during 90-min of treadmill load carriage (LC; 30% body mass; 55 ± 5% V̇O2peak) exercise using indirect calorimetry, and 6-6-[2H2]-glucose PRE and POST. Hgb and Hct increased, and TT performance improved on Days 21 and 27 compared to PRE (p < 0.05). Energy expenditure, fat oxidation, and metabolic clearance rate during LC increased (p < 0.05) from PRE to POST. Myofiber type, protein markers of mitochondrial biogenesis, and capillarization were unchanged PRE to POST. Transcriptional regulation of mitochondrial activity and fat metabolism increased from PRE to POST (p < 0.05). These data indicate EPO administration during 28 days of strenuous exercise can enhance aerobic performance through improved oxygen carrying capacity, whole-body and skeletal muscle fat metabolism.

Enhancing bighead carp cutting: Chilled storage insights and machine vision-based segmentation algorithm development

To enhance market demand and fish utilization, cutting processing is essential for fish. Bighead carp were cut into four primary cuts: head, dorsal, belly, and tail, collectively accounting for 77.03% of the fish's total weight. These cuts were refrigerated at 4 °C for 10 days, during which the muscle from each cut was analyzed. Pseudomonas.fragi proliferated most rapidly and was most abundant in eye muscle (EM), while Aeromonas.sobria showed similar growth patterns in tail muscle (TM). Notably, EM exhibited the highest rate of fat oxidation. TM experienced the most rapid protein degradation. Furthermore, to facilitate the cutting applied in mechanical processing, a machine vision-based algorithm was developed. This algorithm utilized color threshold and morphological parameters to segment image background and divide bighead carp region. Consequently, each cut of bighead carp had a different storage quality and the machine vision-based algorithm proved effective for processing bighead carp.

Algorithm for personalization of diet therapy in patients with atrial fibrillation and obesity based on metabolic status assessment

Aim: To develop an algorithm for personalizing the diet therapy of patients with obesity and atrial fibrillation (AF) based on the assessment of the metabolic status.Material and Methods. The study included 100 patients with grade III obesity and paroxysmal AF. All subjects had nonvalvular AF. Anthropometric parameters, actual nutrition, bioimedance analysis of body composition, basal metabolic rate (BMR) were assessed.Results. Changes in basal metabolism by gender were identified. In women – a decrease in the rate of carboydrate oxidation (CHO) (by 27 ± 12.2%, p &lt; 0.05), an increase in fat oxidation (by 48,58 ± 14.6%, p &lt; 0.01). In men – a decrease in BMR (by 26,23 ± 13.6%, p &lt; 0.05), CHO (by 57,18 ± 18.1%, p &lt; 0.01) and protein (by 28,06 ± 12.9%, p &lt; 0.05), increased rate of fat oxidation (by 31,42 ± 10.0%, p &lt;0.05). A hyperphagic pattern of actual nutrition has been established: excess daily energy intensity (by 16–44%), excess of daily intake of proteins (by 34–54%), fats (by 17% in women) and carbohydrates (by 57–72%, p &lt; 0.05). An excessive amount of saturated fat, cholesterol, and added sugar was revealed in the diet. A deficiency in vitamin D intake was found (by 8–16%, p &lt; 0.05). The maximum daily energy requirement for 95% of women is within 2250 kcal/day, for men – 2950 kcal/day.Conclusion. Metabolic status disorders serve as factors of hemodynamic overload, humoral and electrical dysfunction of the heart. Diet therapy is a powerful component in the treatment and prevention of AF. It is advisable to carry out an algorithm for individual correction of the chemical composition and energy value of diet therapy taking into account the optimal metabolic corridor of needs, enriching the diet with vitamin D, eliminating added sugar, cholesterol, sodium, phosphorus, and sources of vitamin K.

Exercise snacks are a time-efficient alternative to moderate-intensity continuous training for improving cardiorespiratory fitness but not maximal fat oxidation in inactive adults: a randomized controlled trial.

The aims of this study were (1) to determine how stair-climbing-based exercise snacks (ES) compared to moderate-intensity continuous training (MICT) for improving cardiorespiratory fitness (CRF), and (2) to explore whether ES could improve maximal fat oxidation rate (MFO) in inactive adults. Healthy, young, inactive adults (n:42, age: 21.6±2.3 years, BMI: 22.5±3.6kg·m-2, peak oxygen uptake (VO2peak): 33.6±6.3mL·kg-1·min-1) were randomly assigned to ES, MICT, or Control. ES (n=14) and MICT (n=13) groups performed three sessions per week over 6 weeks, while the control group (n=15) maintained their habitual lifestyle. ES involved 3 × 30s "all-out" stair-climbing (6 flight, 126 steps, and 18.9m total height) bouts separated by>1 h rest, and MICT involved 40min×60%-70% HRmax stationary cycling. A significant group×time interaction was found for relative VO2peak (p<0.05) with ES significantly increasing by 7% compared to baseline (MD=2.5mL·kg-1·min-1 (95% CI=1.2, 3.7), Cohen's d=0.44), while MICT had no significant effects (MD=1.0mL·kg-1·min-1 (-1.1, 3.2), Cohen's d=0.17), and Control experienced a significant decrease (MD = -1.7mL·kg-1·min-1 (-2.9, -0.4), Cohen's d=0.26). MFO was unchanged among the three groups (group×time interaction, p>0.05 for all). Stair climbing-based ES are a time-efficient alternative to MICT for improving CRF among inactive adults, but the tested ES intervention appears to have limited potential to increase MFO.

Peak fat oxidation, peak oxygen uptake, and running performance increase during pre-season in sub-elite male football players.

In Football, the high-intensity running bouts during matches are considered decisive. Interestingly, recent studies showed that peak fat oxidation rates (PFO) are higher in football players than other athletes. This study aimed to investigate whether PFO increases following a pre-season. Secondarily, and due to COVID-19, we investigated whether PFO is related to the physical performance in a subgroup of semi-professional male football players. Before and after 8 weeks of pre-season training, 42 sub-elite male football players (18 semi-professionals and 24 non-professionals) had a dual-energy x-ray absorptiometry scan and performed a graded exercise test on a treadmill for the determination of PFO, the exercise intensity eliciting PFO (Fatmax) and peak oxygen uptake (V̇O2peak). Additionally, the semi-professional players performed a Yo-Yo Intermittent Recovery Test level 2 (YYIR2) before and after pre-season training to determine football-specific running performance. PFO increased by 11 ± 10% (mean ± 95% CI), p = 0.031, and V̇O2peak increased by 5 ± 1%, p < 0.001, whereas Fatmax was unchanged (+12 ± 9%, p = 0.057), following pre-season training. PFO increments were not associated with increments in V̇O2peak (Pearson's r2 = 0.00, p = 0.948) or fat-free mass (FFM) (r2 = 0.00, p = 0.969). Concomitantly, YYIR2 performance increased in the semi-professional players by 39 ± 17%, p < 0.001, which was associated with changes in V̇O2peak (r2 = 0.35, p = 0.034) but not PFO (r2 = 0.13, p = 0.244). PFO, V̇O2peak, and FFM increased following pre-season training in sub-elite football players. However, in a subgroup of semi-professional players, increments in PFO were not associated with improvements in YYIR2 performance nor with increments in V̇O2peak and FFM.

Power output at the moderate-to-heavy intensity transition decreases in a non-linear fashion during prolonged exercise

PurposeThe aims of this study were to: (i) describe the time course of the decrease in power output at the moderate-to-heavy intensity transition during prolonged exercise; (ii) investigate the association between durability of the moderate-to-heavy intensity transition and exercise capacity; and (iii) explore physiological correlates of durability of the moderate-to-heavy intensity transition.MethodsTwelve trained cyclists (age: 40 ± 8 y, V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\ ext{V}}$$\\end{document}O2peak: 52.3 ± 5.2 mL·min−1·kg−1) performed an exhaustive cycling protocol involving alternating incremental exercise tests to determine power output at the moderate-to-heavy intensity transition via the first ventilatory threshold (VT1), and 30-min bouts at 90% of the power output at the previously estimated VT1 in the rested state. The individual time course of VT1 was modelled using linear and second-order polynomial functions, and time to a 5% decrease in VT1 (Δ5%VT1) was estimated using the best-fitting model.ResultsPower output at VT1 decreased according to a second-order polynomial function in 11 of 12 participants. Time-to-task failure (234 ± 66 min) was correlated with Δ5%VT1 (139 ± 78 min, rs = 0.676, p = 0.016), and these were strongly correlated with absolute and relative rates of fat oxidation at specific exercise intensities measured during the incremental test performed in the rested state.ConclusionsThese data: (i) identify a non-linear time course of decreases in the moderate-to-heavy intensity transition during prolonged exercise; (ii) support the importance of durability of the moderate-to-heavy intensity transition in prolonged exercise capacity; and (iii) suggest durability of the moderate-to-heavy intensity transition is related to fat oxidation rates.

Substrate utilization and durability during prolonged intermittent exercise in elite road cyclists

PurposeThis study investigated the effects of prolonged intermittent cycling exercise on peak power output (PPO) and 6-min time-trial (6 min-TT) performance in elite and professional road cyclists. Moreover, the study aimed to determine whether changes in performance in the fatigued state could be predicted from substrate utilization during exercise and laboratory measures obtained in a fresh state.MethodsTwelve cyclists (age: 23 years [21;25]; body mass: 71.5 kg [66.7;76.8]; height: 181 cm [178;185]; V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2peak: 73.6 ml kg−1 min−1 [71.2;76.0]) completed a graded submaximal cycling test to determine lactate threshold (LT1), gross efficiency (GE), and maximal fat oxidation (MFO) as well as power output during a maximal 6 min-TT (MPO6 min) in a fresh condition. On a separate day, the cyclists completed a 4-h intermittent cycling protocol with a high CHO intake (100 g h−1). Substrate utilization and PPO was measured hourly during the protocol, which was followed by another 6 min-TT.ResultsMPO6 min and PPO was reduced by 10% [4;15] and 6% [0;6], respectively, after the cycling protocol. These reductions were accompanied by reductions in the anaerobic energy contribution and V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2peak, whereas the average V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2 during the 6 min-TT was unchanged. Correlation analyses showed no strong associations between reductions in MPO6 min and PPO and laboratory measures (i.e., LT1, GE, MFO, V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2peak) obtained in the fresh condition. Additionally, fat oxidation rates during the cycling protocol were not related to changes in neither PPO nor MPO6 min.ConclusionPPO and MPO6 min were reduced following prolonged intermittent cycling, but the magnitude of these reductions could not be predicted from laboratory measures obtained in the fresh condition.