CHO Supplementation Research Articles

Trehalose Improved 20-min Cycling Time-Trial Performance After 100-min Cycling in Amateur Cyclists.

Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a standard high GI CHO. This study investigated the ergogenic and metabolic effects of CHO supplementation with distinct GIs, namely, (a)trehalose (30g/hr), (b)isomaltulose (30g/hr), (c)maltodextrin (60g/hr), and (d)placebo (water). In this double-blind, crossover, counterbalanced, placebo-controlled study, 13 male cyclists cycled a total of 100min at varied exercise intensity (i.e.,10-min stages at 1.5, 2.0, and 2.5W/kg; repeated three times plus two 5-min stages at 1.0W/kg before and after the protocol), followed by a 20-min time trial on four separated occasions. Blood glucose and lactate (every 20min), heart rate, and ratings of perceived exertion were collected throughout, and muscle biopsies were taken before and immediately after exercise. The results showed that trehalose improved time-trial performance compared with placebo (total work done 302 ± 39 vs. 287 ± 48kJ; p = .01), with no other differences between sessions (all p ≥ .07). Throughout the 100-min protocol, blood glucose was higher with maltodextrin compared with the other supplements at all time points (all p < .05). Heart rate, ratings of perceived exertion, muscle glycogen content, blood glucose, and lactate were not different between conditions when considering the 20-min time trial (all p > .05). Trehalose supplementation throughout endurance exercise improved cycling performance and appears to be an appropriate CHO source for exercise tasks up to 2hr. No ergogenic superiority between the different types of CHO was established.

Protective effect of cholecalciferol against cobalt-induced neurotoxicity in rats: ZO-1/iFABP, ChAT/AchE and antioxidant pathways as potential therapeutic targets.

Cobalt (Co) toxicity has been reported to produce central nervous system and gastrointestinal abnormalities. This study assessed the therapeutic effect of cholecalciferol (Cho) supplementation against damages caused by sub-acute (14-day) cobalt chloride (CoCl2) exposure in the brain and intestines. Thirty-five male Wistar rats were divided equally into five groups: Group I (control) received no treatment; Group II received oral CoCl2 (100 mg/kg) only; Groups III, IV, and V received 1000, 3000 and 6000 IU/kg of cholecalciferol, respectively by oral gavage, and concurrently with CoCl2. Cobalt-treated rats showed neuronal vacuolation and presence of pyknotic nuclei in the cerebral cortex and hippocampus, depletion of Purkinje cells in the cerebellum, as well as inflammation and congestion in the intestinal mucosa. Cobalt also increased brain and intestinal hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, while simultaneously reducing glutathione (GSH) content, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities. Further, CoCl2 induced increases in brain acetylcholinesterase (AchE) activity and serum zonulin (ZO-1) levels. Conversely, Cho administration suppressed CoCl2-induced damages in the brain and intestines by reducing lipid peroxidation and increasing the activities of antioxidant enzymes. Remarkably, Cho produced stimulation of brain choline acetyltransferase (ChAT) and suppression of AchE activity, along with dose-dependent reduction in serum levels of ZO-1, intestinal fatty acid-binding protein (iFABP) and nitric oxide. In conclusion, the protective role of cholecalciferol against cobalt-induced toxicity occurred via modulation of cholinergic, intestinal permeability and antioxidant pathways. The results may prove significant in the context of the role of gut-brain connections in neuroprotection.

Effects of In-Exercise Carbohydrate Supplementation on Prolonged High-Intensity Exercise Performance in Oral Contraceptive Users.

To examine the impact of oral contraceptive (OC) phases on performance, physiological, and subjective responses to prolonged, intensive exercise when carbohydrate (CHO) stores are reduced. Ten well-trained female cyclists using monophasic OC completed 4 identical trials (>150min) under conditions of in-trial 60-g·h-1 CHO supplementation (CHO+) or placebo (CHO-) during the sugar- (SUG) and active-pill (ACT) phases of their OC cycle. Each trial comprised two 400-kcal time trials (TT) separated by 1hour of submaximal cycling at first ventilatory threshold. Change in completion time from TT1 to TT2 was minimized in CHO+ compared with CHO- (4.06 [2.55] vs 6.08 [5.33]min; P = .019, effect size = -0.36). An interaction effect of OC and CHO was observed for time to complete TT (P = .006), mean TT power (P = .002), mean TT heart rate (P = .002), and posttrial emotional balance (P = .020) and negative emotional state (P = .033). In ACT, mean TT power and heart rate were higher in CHO+ when compared with CHO-, resulting in faster TTs in CHO+ and improved posttrial emotional well-being. When CHO was not supplemented, TT power and heart rate were higher in SUG when compared with ACT, resulting in faster TTs in SUG and improved posttrial emotional balance. CHO depletion during ACT negatively influenced TT performance and emotional well-being when compared with SUG. Irrespective of OC pill phase, CHO supplementation should be prioritized to sustain performance and improve postexercise recovery-stress balance.

Ketone Monoester Followed by Carbohydrate Ingestion after Glycogen-Lowering Exercise Does Not Improve Subsequent Endurance Cycle Time Trial Performance.

Relative to carbohydrate (CHO) alone, exogenous ketones followed by CHO supplementation during recovery from glycogen-lowering exercise have been shown to increase muscle glycogen resynthesis. However, whether this strategy improves subsequent exercise performance is unknown. The objective of this study was to assess the efficacy of ketone monoester (KME) followed by CHO ingestion after glycogen-lowering exercise on subsequent 20 km (TT20km) and 5 km (TT5km) best-effort time trials. Nine recreationally active men (175.6 ± 5.3 cm, 72.9 ± 7.7 kg, 28 ± 5 y, 12.2 ± 3.2% body fat, VO2max = 56.2 ± 5.8 mL· kg BM-1·min-1; mean ± SD) completed a glycogen-lowering exercise session, followed by 4 h of recovery and subsequent TT20km and TT5km. During the first 2 h of recovery, participants ingested either KME (25 g) followed by CHO at a rate of 1.2 g·kg-1·h-1 (KME + CHO) or an iso-energetic placebo (dextrose) followed by CHO (PLAC + CHO). Blood metabolites during recovery and performance during the subsequent two-time trials were measured. In comparison to PLAC + CHO, KME + CHO displayed greater (p < 0.05) blood beta-hydroxybutyrate concentration during the first 2 h, lower (p < 0.05) blood glucose concentrations at 30 and 60 min, as well as greater (p < 0.05) blood insulin concentration 2 h following ingestion. However, no treatment differences (p > 0.05) in power output nor time to complete either time trial were observed vs. PLAC + CHO. These data indicate that the metabolic changes induced by KME + CHO ingestion following glycogen-lowering exercise are insufficient to enhance subsequent endurance time trial performance.

Metabolic status, reproductive, and productive performances of transition dairy cows as affected by dietary rumen-protected choline supplementation.

Research articles about the effects of rumen-protected choline (RPC) supplementation on metabolic response, and reproductive and productive performances in transitional dairy cows were reviewed and presented. Analysis was conducted on 32 research papers that were published. The papers examined treatments without RPC supplementation and RPC supplementation levels varying from 10 to 100 gm/day. The feeding duration of RPC started from 40 to 140 days prepartum and continued until 20 to 140 days postpartum in multiparous dairy cows. Studies indicated that adding herbal choline (Cho) to the diet of transition dairy cows resulted in increased milk production and improved milk quality, leading to enhanced energy balance and reduced oxidative stress. The concentration and yield of IgG in colostrum provide passive immunity to dairy newborns and can be enhanced by dietary Cho supplementation. The inconsistent effects of RPC supplementation on reproduction may be due to several factors such as heat stress, genetics, and management. RPC supplementation improved the transition dairy cows' milk yield and quality, but dosage response was not observed as in the prior publication. Remarkably, the length of RPC supplementation had a positive correlation with an increase in milk yield. Based on this review, 45-50 gm/day dietary RPC supplementation between 3 weeks pre-calving to 8 weeks post-calving is suggested to increase at least 10% milk yield in dairy cows.

Preoperative Oral Carbohydrate (CHO) Supplementation Is Beneficial for Clinical and Biochemical Outcomes in Patients Undergoing Elective Cesarean Delivery under Spinal Anaesthesia-A Randomized Controlled Trial.

Preoperative fasting and surgery cause metabolic stress, insulin resistance with ketosis, and postoperative nausea and vomiting (PONV). Oral carbohydrate loading strategy (CHO) improves outcomes in labor and general surgery. We aimed to compare the effectiveness of CHO with standard fasting in patients undergoing elective cesarean delivery (CD) under spinal anesthesia. A single-center, parallel, prospective randomized controlled trial (RCT) was conducted in a tertiary university obstetrics department at Pomeranian Medical University in Szczecin, Poland. Patients were randomly assigned (1:1 ratio) to the CHO group (oral carbohydrate 2 h before elective CD, n = 75) or the SF group (control-standard fasting, n = 73). The main outcome measures were incidence and severity of PONV at 6 and 24 h after CD, time to the first peristalsis, time to first bowel movement, and biochemical parameters indicating ketosis in mothers and their children. A total of 148 adult females with singleton pregnancies undergoing elective CD under spinal anesthesia (ASA I and II) were included in the final analysis. At 24 h after CD, 8.0% from the CHO group vs. 20.55% reported three or more episodes of vomiting or dry retching as compared to patients in the SF group (p = 0.041). Preoperative CHO supplementation decreased preoperative feelings of hunger (p < 0.001) and thirst (p < 0.001). Laboratory results in the CHO group showed higher plasma pH (p = 0.001) and glucose (p < 0.001), lower F2-isoprostane in plasma (p = 0.049) and urine (p = 0.018), lower urine F2-isoprostane/creatinine ratio (p = 0.045) than in the SF group. HOMA-IR (p < 0.001) and lactate (p < 0.001) were higher in the CHO group than in the control group. There was no significant difference in the incidence or severity of early PONV at 6 h. The incidence of vomiting or dry retching at 24 h after cesarean delivery was lower in the CHO group as compared to standard starvation, but the combined results of PONV frequency and severity on the Wengritzky scale did not differ between the two study groups. Preoperative CHO supplementation decreased preoperative feelings of hunger and thirst, enhancing the comfort of pregnant women. ClinicalTrials.gov identifier: NCT04069806.

Carbohydrate intake before and during high intensity exercise with reduced muscle glycogen availability affects the speed of muscle reoxygenation and performance.

Muscle glycogen state and carbohydrate (CHO) supplementation before and during exercise may impact responses to high-intensity interval training (HIIT). This study determined cardiorespiratory, substrate metabolism, muscle oxygenation, and performance when completing HIIT with or without CHO supplementation in a muscle glycogen depleted state. On two occasions, in a cross-over design, eight male cyclists performed a glycogen depletion protocol prior to HIIT during which either a 6% CHO drink (60g.hr-1) or placebo (%CHO, PLA) was consumed. HIIT consisted of 5 × 2min at 80% peak power output (PPO), 3 × 10-min bouts of steady-state (SS) cycling (50, 55, 60% PPO), and a time-to-exhaustion (TTE) test. There was no difference in SS [Formula: see text], HR, substrate oxidation and gross efficiency (GE %) between CHO and PLA conditions. A faster rate of muscle reoxygenation (%. s-1) existed in PLA after the 1st (Δ-0.23 ± 0.22, d = 0.58, P < 0.05) and 3rd HIIT intervals (Δ-0.34 ± 0.25, d = 1.02, P < 0.05). TTE was greater in CHO (7.1 ± 5.4min) than PLA (2.5 ± 2.3min, d = 0.98, P < 0.05). CHO consumption before and during exercise under reduced muscle glycogen conditions did not suppress fat oxidation, suggesting a strong regulatory role of muscle glycogen on substrate metabolism. However, CHO ingestion provided a performance benefit under intense exercise conditions commenced with reduced muscle glycogen. More research is needed to understand the significance of altered muscle oxygenation patterns during exercise.

Carbohydrate Considerations for Athletes with a Spinal Cord Injury.

The Paralympic movement is growing in popularity, resulting in increased numbers of athletes with a spinal cord injury (SCI) competing in various sport disciplines. Athletes with an SCI require specialized recommendations to promote health and to maximize performance, as evidenced by their metabolic and physiological adaptations. Nutrition is a key factor for optimal performance; however, scientifically supported nutritional recommendations are limited. This review summarizes the current knowledge regarding the importance of carbohydrates (CHO) for health and performance in athletes with an SCI. Factors possibly affecting CHO needs, such as muscle atrophy, reduced energy expenditure, and secondary complications are analyzed comprehensively. Furthermore, a model calculation for CHO requirements during an endurance event is provided. Along with assessing the effectiveness of CHO supplementation in the athletic population with SCI, the evaluation of their CHO intake from the available research supplies background to current practices. Finally, future directions are identified. In conclusion, the direct transfer of CHO guidelines from able-bodied (AB) athletes to athletes with an SCI does not seem to be reasonable. Based on the critical role of CHOs in exercise performance, establishing recommendations for athletes with an SCI should be the overall objective for prospective research.

English

Background: Long distance practice running are growing and nutritional ergogenic are commonly used as a potential aid in final training and competition performance. Caffeine (CAF) and carbohydrates (CHO) are among the most commonly used supplements due to their expected ergogenic properties that can optimize energetic systems. The objective of this study was to examine potential changes in 10-km running performance with acute isolated and combined CAF and CHO supplementation. Material and method: Fifteen recreational endurance-trained runners performed four 10-km running performance on an official athletic track (400 m) under four supplementation conditions: placebo and placebo (PLA+PLA), placebo and caffeine (PLA+CAF), placebo and carbohydrates (PLA+CHO), caffeine and carbohydrates (CAF+CHO). CAF and CHO supplementation consisted of capsules of 6 mg·kg-1 and 8% CHO solution (1 g·kg-1) respectively, ingested 60 and 30 minutes before the performance tests. Placebo was obtained through empty capsules for CAF and juice for CHO without sugar (Clight®). During each trial running speed to calculate 10-km mean velocity (MV) and maximum heart rate (HRmax) were analyzed. Results: There was a difference in the pacing strategy adopted by the runners with higher MV during the initial phase for PLA+CAF and CAF+CHO groups and in the final phase for PLA+ CHO. However, there was no statistically significant difference in 10-km running performance between the conditions, as well as for HRmax. Conclusions: The use of acute, isolated and combined CAF+CHO supplementation had influence in the pacing strategy, but no in 10- km final performance, of recreational runners.

The effect of choline availability from gestation to early development on brain and retina functions and phospholipid composition in a male mouse model

ABSTRACT Objectives Although choline is essential for brain development and neural function, the effect of choline on retina function is not well understood. This study examined the effects of choline on neural tissues of brain and retina, and membrane phospholipid (PL) composition during fetal development. Methods Pregnant C57BL/6 mice were fed one of 4 choline modified diets: i) control (Cont, 2.5g/kg), ii) choline deficient (Def, 0g/kg), iii) supplemented with choline chloride (Cho, 10g/kg) and iv) supplemented with egg phosphatidylcholine (PC, 10g/kg). At postnatal day (PD) 21, pups were weaned onto their mothers’ respective diets until PD 45. Spatial memory was measured using the Morris Water Maze; retina function by electroretinogram (ERG); and PL composition with nuclear magnetic resonance spectroscopy. Results Cho and PC supplementation enhanced cued learning and spatial memory abilities, respectively (p Def > PC > Cho, with no statistically significant alterations in cone-driven responses. There were no differences in the composition of major PLs in the brain and retina. In the brain, subclasses of ether PL, alkyl acyl- phosphatidylethanolamine (PEaa) and phosphatidylcholine (PCaa) were significantly greater among the PC supplemented group in comparison to the Def group. Discussion These results indicate that while choline supplementation during gestation to an early developmental period is beneficial for spatial memory, contributions to retina function are minor. Assessment with a larger sample size of retinas could warrant the essentiality of choline for retina development.

Pre-Sleep Low Glycemic Index Modified Starch Does Not Improve Next-Morning Fuel Selection or Running Performance in Male and Female Endurance Athletes

To determine the effects of pre-sleep supplementation with a novel low glycemic index (LGI) carbohydrate (CHO) on next-morning substrate utilization, gastrointestinal distress (GID), and endurance running performance (5-km time-trial, TT). Using a double-blind, randomized, placebo (PLA) controlled, crossover design, trained participants (n = 14; 28 ± 9 years, 8/6 male/female, 55 ± 7 mL/kg/min) consumed a LGI, high glycemic index (HGI), or 0 kcal PLA supplement ≥ 2 h after their last meal and <30 min prior to sleep. Upon arrival, resting energy expenditure (REE), substrate utilization, blood glucose, satiety, and GID were assessed. An incremental exercise test (IET) was performed at 55, 65, and 75% peak volume of oxygen consumption (VO2peak) with GID, rating of perceived exertion (RPE) and substrate utilization recorded each stage. Finally, participants completed the 5-km TT. There were no differences in any baseline measure. During IET, CHO utilization tended to be greater with LGI (PLA, 56 ± 11; HGI, 60 ± 14; LGI, 63 ± 14%, p = 0.16, η2 = 0.14). GID was unaffected by supplementation at any point (p > 0.05). Performance was also unaffected by supplement (PLA, 21.6 ± 9.5; HGI, 23.0 ± 7.8; LGI, 24.1 ± 4.5 min, p = 0.94, η2 = 0.01). Pre-sleep CHO supplementation did not affect next-morning resting metabolism, BG, GID, or 5-km TT performance. The trend towards higher CHO utilization during IET after pre-sleep LGI, suggests that such supplementation increases morning CHO availability.

Acute carbohydrate loading on anaerobic threshold and VO2 max in active college aged individuals

Carbohydrate (CHO) loading is believed to be an ergogenic dietary asset for aerobic performance by maximizing CHO oxidation and to combat glycogen depletion within the working muscle cells. However, evidence-based research has displayed that an increase in fat metabolism, subsequently lower CHO oxidation, may provide sufficient energy during submaximal and maximal exertion through beta oxidation.​​For this reason, active volunteers were recruited to undergo a double-blind study to determine if an acute carbohydrate loading dietary supplement was effective in enhancing performance on a maximal oxygen uptake (VO2) test.​​Eleven college aged (22.09​±1.3) students ​(male n=8, female n=3) participated in this double-blind randomized study. Subjects consumed either a CHO (1g/kg body weight) or placebo supplement followed by a 12 hour fast. Following this fast, first testing session consisted of a seven-point skin caliper for body composition (% body fat), fasting blood glucose as measured by point of care finger stick method using Abbott Precision blood glucose meter (mg/dL), and a VO2 max test (mL/kg/min) measured by a modified Tread Sport Treadmill Protocol. Prior to the second test date, the subject consumed either CHO supplement or placebo, followed by 12 hour fast. Second test day consisted of fasting blood glucose, and VO2​ max test. Protocols were matched for the second bout of testing.​​A paired samples t-test (SPSS v.26) was conducted to determine significance (​p≤0.05​) on each of the four variables: VO2 max, fasting blood glucose (GLU), anaerobic threshold (AT), and respiratory quotient (RQ). No significant differences were found when comparing groups on all variables (VO2 ​p=0.923​,GLU ​p​=0.099​,AT ​p=0.641, ​RQ ​p=0.372​).​​ Acute CHO loading has no significant impact on performance variables as defined by AT, RQ, and VO2 max.

The Performance Effect of Scheduled Carbohydrate and Caffeine Intake during Simulated Team Sport Match-Play.

The aim of the current investigation was to identify the effects of scheduled carbohydrate (CHO) and caffeine (CAF) supplementation on simulated team sport match-play performance. Ten male hurling players completed three hurling match-play simulation protocols (HSP) performed 7 days apart in a double-blind, randomized design. Supplementation included CHO, CHO + CAF, and placebo (PLA). In a randomized order, participants ingested either a 6% CHO solution, a PLA solution of similar taste, or a combined intake of 6% CHO solution + 200 mg CAF capsule. At specific time points (Pre-0 min; half time (HT)-30 min; full time (FT)-60 min), participants completed a repeated sprint protocol (RAST; 12 × 20 m). Physiological [% maximal oxygen uptake (%VO2max), % mean oxygen uptake (%VO2mean), % maximal heart rate (%HRmax), % mean heart rate (%HRmean), respiratory exchange ratio (RER), and blood lactate (BLa)] and performance [(best sprint time (RSAbest), mean sprint time (RSAmean), and rate of perceived exertion (RPE)] variables were monitored throughout each simulation. Non-significant differences were observed between supplement trials (CHO, CHO + CAF, and PLA) for BLa (η2 = 0.001, small), %VO2max (η2 = 0.001, small), %VO2mean (η2 = 0.004, small), %HRmax (η2 = 0.007, small), %HRmean (η2 = 0.018, small), RER (η2 = 0.007, small), RPE (η2 = 0.007, small), and RSAbest (η2 = 0.050, small). RSAmean performance significantly improved in CHO + CAF trials compared to PLA, with sprint times significantly improved from Pre to FT also (η2 = 0.135, medium). A significant difference was observed in BLa between time points (Pre, HT, and FT) (η2 = 0.884, large) in % HRmax (η2 = 0.202, medium), %HRmean (η2 = 0.477, large), and RER (η2 = 0.554, large) across halves and in RPE across time points (η2 = 0.670, large). Our data provide novel data regarding the effects of CHO and CAF supplementation on team sport performance, with co-ingestion of CHO + CAF reducing the decrement in repeated sprint performance compared to PLA.

Carbohydrate supplementation and psychophysiological responses during moderate exercise in hypoxia

BackgroundRating of Perceived Exertion (RPE) is a subjective scale to monitor overload and fatigue during exercise. Hypoxia may worsen the perception of fatigue, compromising the self-reported perception of effort and increasing RPE. The objective was to evaluate the effects of carbohydrate (CHO) supplementation on RPE during exercise in hypoxia simulating 4200 m.MethodsEight male physically active volunteers performed two exercises at 50% VO2peak and 1% slope: exercise in hypoxia + placebo or exercise in hypoxia + CHO (6% maltodextrin) with supplementation at 20, 40, and 60 min during exercise. Oxygen Saturation (SaO2%) was assessed at baseline and after exercise, while RPE and HR were measured each 10 min during the trial.ResultsSaO2% decreased after exercise in both conditions of hypoxia compared to rest. The RPE did not differ between groups. However, the RPE increased in hypoxia after 20 min of exercise in relation to 10 min. The Area Under the Curve (AUC) of RPE was lower in hypoxia + CHO compared to hypoxia. The AUC of the HR/RPE ratio in the hypoxia + CHO group was higher in relation to hypoxia.ConclusionsOur results indicate that CHO supplementation does not change RPE induced by 60 min of exercise at 50% VO2peak in hypoxia equivalent to 4200 m at the different times analyzed. However, in hypoxia + CHO the (AUC)-60 min of total RPE decreased during exercise, while the heart rate/RPE ratio improved, indicating lower RPE in the hypoxic environment.

Supplement with whey protein hydrolysate in contrast to carbohydrate supports mitochondrial adaptations in trained runners

BackgroundProtein supplementation has been suggested to augment endurance training adaptations by increasing mixed muscle and myofibrillar protein synthesis and lean body mass. However, a potential beneficial effect on mitochondrial adaptations is yet to be clarified.The aim of the present study was to investigate the effect of consuming whey protein hydrolysate before and whey protein hydrolysate plus carbohydrate (PRO-CHO) after each exercise session during a six-week training period compared to similarly timed intake of isocaloric CHO supplements on biomarkers of mitochondrial biogenesis, VO2max and performance in trained runners.MethodsTwenty-four trained runners (VO2max 60.7 ± 3.7 ml O2 kg− 1 min1) completed a six-week block randomized controlled intervention period, consisting of progressive running training. Subjects were randomly assigned to either PRO-CHO or CHO and matched in pairs for gender, age, VO2max, training and performance status. The PRO-CHO group ingested a protein beverage (0.3 g kg− 1) before and protein-carbohydrate beverage (0.3 g protein kg− 1 and 1 g carbohydrate kg− 1) after each exercise session. The CHO group ingested an energy matched carbohydrate beverage. Resting muscle biopsies obtained pre and post intervention were analyzed for mitochondrial specific enzyme activity and mitochondrial protein content. Subjects completed a 6 K time trial (6 K TT) and a VO2max test pre, midway (only 6 K TT) and post intervention.ResultsFollowing six weeks of endurance training Cytochrome C (Cyt C) protein content was significantly higher in the PRO-CHO group compared to the CHO group (p < 0.05), with several other mitochondrial proteins (Succinate dehydrogenase (SDHA), Cytochrome C oxidase (COX-IV), Voltage-dependent anion channel (VDAC), Heat shock protein 60 (HSP60), and Prohibitin (PHB1)) following a similar, but non-significant pattern (p = 0.07–0.14). β-hydroxyacyl-CoA dehydrogenase (HAD) activity was significantly lower after training in the CHO group (p < 0.01), but not in the PRO-CHO group (p = 0.24). VO2max and 6 K TT was significantly improved after training with no significant difference between groups.ConclusionIntake of whey PRO hydrolysate before and whey PRO hydrolysate plus CHO after each exercise session during a six-week endurance training period may augment training effects on specific mitochondrial proteins compared to intake of iso-caloric CHO but does not alter VO2max or 6 K TT performance.Trial registrationclinicaltrials.gov, NCT03561337. Registered 6 June 2018 – Retrospectively registered.

The Effect of Carbohydrate Ingestion Following Eccentric Resistance Exercise on AKT/mTOR and ERK Pathways: A Randomized, Double-Blinded, Crossover Study.

To determine the acute effects of carbohydrate (CHO) ingestion following a bout of maximal eccentric resistance exercise on key anabolic kinases of mammalian target of rapamycin and extracellular signal-regulated kinase (ERK) pathways. The authors' hypothesis was that the activation of anabolic signaling pathways known to be upregulated by resistance exercise would be further stimulated by the physiological hyperinsulinemia resulting from CHO supplementation. Ten resistance-trained men were randomized in a crossover, double-blind, placebo (PLA)-controlled manner to ingest either a noncaloric PLA or 3g/kg of CHO beverage throughout recovery from resistance exercise. Muscle biopsies were collected at rest, immediately after a single bout of intense lower body resistance exercise, and after 3hr of recovery. CHO ingestion elevated plasma glucose and insulin concentrations throughout recovery compared with PLA ingestion. The ERK pathway (phosphorylation of ERK1/2 [Thr202/Tyr204], RSK [Ser380], and p70S6K [Thr421/Ser424]) was markedly activated immediately after resistance exercise, without any effect of CHO supplementation. The phosphorylation state of AKT (Thr308) was unchanged postexercise in the PLA trial and increased at 3hr of recovery above resting with ingestion of CHO compared with PLA. Despite stimulating-marked phosphorylation of AKT, CHO ingestion did not enhance resistance exercise-induced phosphorylation of p70S6K (Thr389) and rpS6 (Ser235/236 and Ser240/244). CHO supplementation after resistance exercise and hyperinsulinemia does not influence the ERK pathway nor the mTORC1 target p70S6K and its downstream proteins, despite the increased AKT phosphorylation.

Effects of carbohydrate and glutamine supplementation on cytokine production by monocytes after exercise in hypoxia: A crossover, randomized, double-blind pilot study.

The aim of this study was to evaluate the combined effects of carbohydrate (CHO) and glutamine (Gln) supplementation on cytokine production by monocytes after exercise until exhaustion performed in hypoxia. Fifteen physically active men underwent three exercises until exhaustion with an intensity of 70% maximal oxygen intake at a simulated height of 4500 m under the following supplementation: placebo, CHO (maltodextrin 8%/200 mL for 20 min), and CHO + Gln (Gln 20 g/d for 6 d and maltodextrin 8%/200 mL for 20 min) during exercise and for 2 h of recovery. Analysis of variance for repeated measures followed by the Tukey's post hoc test was realized and P < 0.05 was considered statistically significant. Oxygen saturation of arterial blood (SaO2%) decreased in the three trials compared with baseline. Two hours post-exercise, the SaO2% was high in CHO + Gln condition compared with placebo. Two hours after exercise, interleukin (IL)-1β decreased compared with post-exercise in placebo and was lower compared with baseline in the CHO + Gln condition. Tumor necrosis factor-α decreased 2 h after exercise compared with baseline and pre-exercise in the CHO + Gln condition. No changes were observed in myeloperoxidase or IL-6 production. Two hours after exercise, Gln decreased compared with baseline and post-exercise in placebo and decreased 2 h after exercise in relation to post-exercise in the CHO condition. Gln increased post-exercise compared with pre-exercise in the CHO + Gln condition. Although erythropoietin did not change in this condition, it was high post-exercise and 2 h after exercise in the placebo condition compared with baseline and 2 h after exercise compared with baseline and pre-exercise in the CHO condition. Gln supplementation for 6 d before exercise, associated with CHO supplementation during exercise, was able to revert Gln reduction after exercise and after 2 h of recovery and may have contributed to reducing tumor necrosis factor-α production, suggesting a possible anti-inflammatory effect of supplementation.

Glucose Ingestion Inhibits Endurance Exercise-Induced IL-6 Producing Macrophage Infiltration in Mice Muscle.

Background: Carbohydrate (CHO) supplementation during exercise attenuates exercise-induced increases in plasma Interleukin (IL)-6 concentration. However, the effects of CHO supplementation on muscle IL-6 production during endurance exercise is controversial. The purpose of this study was to investigate the effects of CHO supplementation on muscle IL-6 production during endurance exercise with a special focus on the IL-6 producing cells. Methods: C57BL/6J mice were divided into three groups—sedentary with water ingestion group as the control (Con; n = 10), exercise with water ingestion group (Ex; n = 10), and exercise with 6% glucose ingestion group (Ex + glucose; n = 10). The Ex and Ex + glucose groups completed 3 h of treadmill running (24 m/min, 7% incline) and were sacrificed immediately after exercise. Results: The exercise-induced increases of plasma IL-6 concentration and gastrocnemius IL-6 gene expression were attenuated by glucose ingestion. However, the increases of soleus IL-6 gene expression and gastrocnemius and soleus IL-6 protein expression were not attenuated by glucose ingestion. Furthermore, we observed that macrophages that infiltrated muscle produce IL-6 and glucose ingestion attenuated the infiltration of IL-6-producing macrophages. Conclusion: This study revealed that infiltrating macrophages may be one type of IL-6-producing cells during endurance exercise, and the infiltration of these cells in muscle was attenuated by glucose ingestion. However, the effects of glucose ingestion on muscle IL-6 production were limited.

Carbohydrate Effects on Post-Exercise Performance in Prepubescent Girls

Carbohydrate (CHO) consumption is a common practice during variable-intensity exercise (VIE) such as team sports. The effects of CHO on performance during VIE have been studied in adults; however, the effects are less defined in children and apparently not at all in prepubescent girls. PURPOSE: To investigate the effects of a 6% CHO drink on a one-minute performance test following 30-minutes of VIE in prepubescent girls. METHODS: Ten girls (10.4±0.7 yrs.) participated in this study. During the initial visit, maximal aerobic power was determined followed by a familiarization of the protocol used during the next two visits in which the child consumed either a CHO drink or an electrolyte-matched placebo (PL). The experimental protocol involved two 15-minute bouts of VIE (20, 55, 95% maximal aerobic power and 6-second maximal sprint); beverages were consumed prior to exercise and after each 15-minute segment. A one-minute performance trial was then completed at maximal effort. Measurements during VIE included heart rate (HR), rating of perceived exertion (RPE), sprint mean power (MP) and sprint peak power (PP). During the one-minute performance bout, HR, RPE, PP, total work (TW), and fatigue index (FI) were assessed. Data were analyzed using a 2-way ANOVA and paired t-tests. RESULTS: VO2max was 39.7±5.5 mL∙kg-1∙min-1 and HRmax was 196±11 bpm. During VIE, there were no interaction effects, no trial effects (p>0.05) for HR, %HRmax, RPE, sprint MP, sprint PP and no time effects (p>0.05) for HR, %HRmax, or MP. However, there were time effects (p<0.05) for RPE (VIE1<VIE2) and PP (VIE1>VIE2). No differences were found between trials (CHO vs. PL) for one-minute performance for HR (190±9 vs. 189±9 bpm), %HRmax (97.0±3.2 vs. 96.6±3.0 %), RPE (7.8±2.3 vs. 8.1±1.9), PP (238±70 vs. 235±60 W), FI (54.7±10.0 vs. 55.9±12.8 %), and TW (9.37±2.6 vs. 9.37±2.1 kJ). CONCLUSION: A 6% CHO drink is ineffective at improving one-minute performance following 30-minutes of VIE in pre-pubertal girls. Based upon the current findings, CHO supplementation does not appear to be beneficial with respect to improving performance for prepubescent children completing VIE activity lasting 30-minutes.

Different trophic groups of arboreal ants show differential responses to resource supplementation in a neotropical savanna.

Resource-ratio theory predicts that consumers should achieve optimal ratios of complementary nutrients. Accordingly, different trophic groups are expected to vary in their N-limitation depending on the extent to which they feed primarily on carbohydrate (CHO) or protein. Among arboreal ants, N-limitation ranges from high (for trophobiont tenders), intermediate (leaf foragers) and low (predators). We report results from a manipulative field experiment in a Brazilian savanna that tests the differential attractiveness of nitrogen and CHO to arboreal ants, as well as experimentally examines changes in broader ant foraging patterns in response to protein and CHO supplementation. Every tree within 32 20 × 20m plots were supplemented with either protein, CHO; protein + CHO or a water control (n = 8 in each case) for a 7-day period in each of the wet and dry seasons. As predicted, different trophic groups responded differentially to supplementation treatment according to the extent of their N-limitation. The richness and abundance of the most N-limited group (trophobiont tenders) was highest at protein supplements, whereas less N-limited trophic groups showed highest species richness (leaf foragers) or abundance (predators) at CHO supplements. Protein supplementation markedly increased the general foraging abundance of trophobiont tenders, but decreased the abundance of leaf foragers. We attribute the latter to increased competition from behaviorally dominant trophobiont tenders. Our study provides experimental evidence that nutrient availability is a major factor influencing arboreal ant communities, both directly through the provision of different resources, and indirectly through increased competitive pressure.