Co-ingestion Of Carbohydrate Research Articles

Acute Ingestion of a Ketone Monoester without Co-ingestion of Carbohydrate Improves Running Economy in Male Endurance Runners.

Acute ingestion of a ketone monoester, with and without co-ingestion of carbohydrate, was investigated for effects on running economy (RE), time to exhaustion (TTE), and other related indices of endurance running performance. Using a three condition, placebo-controlled, randomized crossover design, 11 male middle- and long-distance runners ran at five submaximal speeds (10-14 km·h -1 ) on a motorized treadmill for 8 min each, immediately followed by a ramp test to volitional exhaustion. Participants consumed either a 10% carbohydrate solution (CHO), a 10% carbohydrate solution with 750 mg·kg -1 body mass of an ( R )-3-hydroxybutyl ( R )-3-hydroxybutyrate ketone monoester (CHO + KE), or 750 mg·kg -1 body mass of the ketone monoester in flavored water (KE) before (two-thirds of the dose) and during (one-third of the dose) exercise. β-hydroxybutyrate concentration averaged 1.8 ± 0.3 and 2.1 ± 0.3 mM during exercise in CHO + KE and KE, respectively. RE was lower at each submaximal running speed (effect size = 0.48-0.98) by an average of 4.1% in KE compared with CHO, but not between CHO + KE and CHO. TTE did not differ between CHO (369 ± 116 s), CHO + KE (342 ± 99 s), or KE (333 ± 106 s) ( P = 0.093). Acute ingestion of a ketone monoester without carbohydrate, but not when coingested with carbohydrate, improved RE in middle- and long-distance runners at a range of submaximal running speeds and did not alter TTE in a short-duration ramp test to volitional exhaustion. Further investigation is required to examine if these differences translate into positive performance outcomes over longer durations of exercise.

Effect Of Co-ingestion Of Carbohydrate With Milk Post-exercise In Women By Menstrual Cycle Phase

PURPOSE: The effect of the post-exercise milk ingestion or co-ingestion of carbohydrate with milk contributes to the recovery of substrate and exercise capacity. However, little information exists on the effect of post-exercise milk consumption on substrate responses and subsequent performance in women. Estrogen, levels of which change with the menstrual cycle, increases fat metabolism. Therefore, one must consider the menstrual cycle when examining the effect of post-exercise milk ingestion in women. Here we aimed to assess the effects of a milk-based beverage on substrate recovery and subsequent exercise performance in women by menstrual cycle phase. METHODS: Twelve women with regular menstrual cycles participated (age, 22.2 ± 2.0 years; height, 1.59 ± 0.55 m; weight, 55.1 ± 6.0 kg; body mass index, 21.7 ± 1.9 kg/m2). The subjects performed glycogen-depleting exercise in the early follicular phase (EF) or late follicular phase (LF), followed by a 240-min recovery period, during which they ingested a carbohydrate beverage (control [CON] group) or carbohydrate dissolved in milk (MILK group). After 240 min, the subjects completed a performance test to exhaustion at 90% maximal workload capacity. Baseline blood samples were taken for the analysis of estradiol and progesterone levels. At t = 0, 120, and 240 min post-exercise, blood samples were taken for the determination of blood glucose, lactate, free fatty acid (FFA), and insulin levels. RESULTS: Serum estradiol levels were significantly higher in the LF (CON and MILK) than in the EF (CON and MILK) (p < 0.01). Serum progesterone levels were not significantly in each group at baseline (p = 0.054). The area under the curve (AUC) of FFA from t = 120 to t = 240 was significantly greater in the MILK (EF and LF) than in the CON (EF and LF) group (12.9 ± 2.3, 13.3 ± 3.6, 18.9 ± 5.5, 18.7 ± 5.6 for the EF + CON, LF + CON, EF + MILK, and LF + MILK, respectively; p < 0.05). There was a significant positive correlation between performance test completion and the AUC of FFA from t = 0 to t = 240 in each group (EF + CON, r = 0.69, p < 0.05; LF + CON, r = 0.59, p < 0.05; EF + MILK, r = 0.83, p < 0.01; LF + MILK, r = 0.65, p < 0.05). CONCLUSION: Our results suggest that circulating substrate and hormone levels during the short post-exercise recovery period may be affected by differences in beverage intake but not the menstrual cycle.

Acute effects of prior dietary fat ingestion on postprandial metabolic responses to protein and carbohydrate co-ingestion in overweight and obese men: A randomised crossover trial

Obesity and insulin resistance are associated with an impaired sensitivity to anabolic stimuli such as dietary protein (anabolic resistance). Omega-3 polyunsaturated fatty acids (n-3 PUFA) may be protective against the deleterious effects of saturated fatty acids (SFA) on insulin resistance. However, the contribution of excess fat consumption to anabolic and insulin resistance and the interaction between SFA and n-3 PUFA is not well studied. The primary aim of this study was to investigate the effects of an oral fat pre-load, with or without the partial substitution of SFA with fish oil (FO)-derived n-3 PUFA, on indices of insulin and anabolic sensitivity in response to subsequent dietary protein and carbohydrate (dextrose) co-ingestion. Eight middle-aged males with overweight or obesity (52.8±2.0yr, BMI 31.8±1.4kg·m-2) ingested either an SFA, or isoenergetic SFA and FO emulsion (FO), or water/control (Con), 4h prior to a bolus of milk protein and dextrose. Lipid ingestion (in particular FO) impaired the early postprandial uptake of branched chain amino acids (BCAA) into the skeletal muscle in response to protein and dextrose, and attenuated the peak glycaemic response, but was not accompanied by differences in whole body (Matsuda Index: Con: 4.66±0.89, SFA: 5.10±0.94 and FO: 4.07±0.59) or peripheral (forearm glucose netAUC: Con: 521.7±101.7; SFA: 470.2±125.5 and FO: 495.3±101.6μmol·min-1·100g lean mass·min [t=240-420min]) insulin sensitivity between visits. Postprandial whole body fat oxidation was affected by visit (P=0.024) with elevated rates in SFA and FO, relative to Con (1.85±0.55; 2.19±0.21 and 0.65±0.35kJ·h-1·kg-1 lean body mass, respectively), however muscle uptake of free fatty acids (FFA) was unaffected. Oral lipid preloads, consisting of SFA and FO, impair the early postprandial BCAA uptake into skeletal muscle, which occurs independent of changes in insulin sensitivity. ClinicalTrials.gov Identifier NCT03146286.

The Effect of Co-Ingestion of Carbohydrate with Milk after Exercise in Healthy Women: Study Considering the Menstrual Cycle.

This study aimed to assess the effects of co-ingestion of carbohydrate with milk (MILK) and isocaloric carbohydrate beverage (CHO) on post-exercise recovery and subsequent exercise capacity, considering the menstrual cycle. This study included 12 women with regular menstrual cycles who completed four test days, which started with glycogen-depleting exercise using a cycle ergometer in the early follicular phase (EF) and late follicular phase (LF), followed by 240 min of recovery from the ingestion of 200 mL of CHO or MILK every 30 min immediately after the exercise (POST0) until 210 min post-exercise. After 240 min, participants performed an exercise capacity test. Blood samples and breathing gas samples were collected before the exercise (PRE), POST0, and 120 (POST120) and 240 min after the end of exercise (POST240) to determine the concentrations of estradiol, progesterone, blood glucose, blood lactate, free fatty acid (FFA), and insulin and the respiratory exchange ratio, fat oxidation, and carbohydrate oxidation. The exercise time at exercise capacity test was not significantly different in terms of menstrual cycle phases and recovery beverages ingested. However, there was a significant positive correlation between the exercise capacity test and area under the curve (AUC) of FFA concentrations from POST0 to POST240 in each group (EF + CHO, p < 0.05; LF + CHO, p < 0.05; EF + MILK, p < 0.01; and LF + MILK, p < 0.05). The AUC of FFA from POST120 to POST240 showed no difference between EF (CHO and MILK) and LF (CHO and MILK). However, the AUC of FFA concentrations from POST120 to POST240 was significantly greater in MILK (EF and LF) than that in CHO (EF and LF) (p < 0.05). In active women, circulating substrates and hormone concentrations during short recovery post-exercise are not affected by the menstrual cycle. However, MILK may affect circulating substrates during recovery and the exercise capacity after recovery.

Coingestion of Carbohydrate and Protein on Muscle Glycogen Synthesis after Exercise: A Meta-analysis.

Evidence suggests that carbohydrate and protein (CHO-PRO) ingestion after exercise enhances muscle glycogen repletion to a greater extent than carbohydrate (CHO) alone. However, there is no consensus at this point, and results across studies are mixed, which may be attributable to differences in energy content and carbohydrate intake relative to body mass consumed after exercise. The purpose of this study was determine the overall effects of CHO-PRO and the independent effects of energy and relative carbohydrate content of CHO-PRO supplementation on postexercise muscle glycogen synthesis compared with CHO alone. Meta-analysis was conducted on crossover studies assessing the influence of CHO-PRO compared with CHO alone on postexercise muscle glycogen synthesis. Studies were identified in a systematic review from PubMed and Cochrane Library databases. Data are presented as effect size (95% confidence interval [CI]) using Hedges' g. Subgroup analyses were conducted to evaluate effects of isocaloric and nonisocaloric energy content and dichotomized by median relative carbohydrate (high, ≥0.8 g·kg-1⋅h-1; low, <0.8 g·kg-1⋅h-1) content on glycogen synthesis. Twenty studies were included in the analysis. CHO-PRO had no overall effect on glycogen synthesis (0.13, 95% CI = -0.04 to 0.29) compared with CHO. Subgroup analysis found that CHO-PRO had a positive effect (0.26, 95% CI = 0.04-0.49) on glycogen synthesis when the combined intervention provided more energy than CHO. Glycogen synthesis was not significant (-0.05, 95% CI = -0.23 to 0.13) in CHO-PRO compared with CON when matched for energy content. There was no statistical difference of CHO-PRO on glycogen synthesis in high (0.07, 95% CI = -0.11 to 0.22) or low (0.21, 95% CI = -0.08 to 0.50) carbohydrate content compared with CHO. Glycogen synthesis rates are enhanced when CHO-PRO are coingested after exercise compared with CHO only when the added energy of protein is consumed in addition to, not in place of, carbohydrate.

Co-ingestion of carbohydrate and whey protein induces muscle strength and myofibrillar protein accretion without a requirement of satellite cell activation.

Muscle development is controlled by the balance between muscle protein synthesis and protein degradation. Protein supplementation has been widely known to enhance muscle protein synthesis, and carbohydrate supplementation may attenuate protein degradation. The purpose of this study was to compare the effects of whey protein plus carbohydrate (CP), whey protein (WP), and placebo (PLA) supplements on resistance training adaptations. Two-month old rats were trained by ladder climbing every 3 days for 8 weeks. PLA, WP, or CP was given immediately after each exercise session. Non-exercise rats were used as a sedentary control (SED). Total body composition was assessed and blood samples were collected before, middle, and end of training. The flexor hallucis longus (FHL) was excised 24 h after the last exercise session. Following training, maximal carrying capacity was significantly greater in CP than PLA and WP. This improved training performance in CP paralleled an increase in total muscle and myofibrillar protein content. Muscle and fiber cross sectional areas (CSA) were significantly increased by exercise training, with a concomitant increase in myonuclear domain. CP significantly elevated IGF-1 protein expression over SED, but there were no significant differences in myostatin, Pax7, MyoD, or myogenin across treatment groups. There was also no difference in the number of total nuclei in each fiber CSA among groups. Corticosterone levels were significantly elevated in PLA and WP over 8 weeks of training, whereas this change in corticosterone over time was not observed in the CP group. The results suggest that the greater improvement of maximal caring capacity for CP compared with PLA and WP was associated with a greater increase in myofibrillar protein content. Satellite cell activation did not appear to contribute to the observed gains in muscle hypertrophy and strength.

Maximizing Post-exercise Anabolism: The Case for Relative Protein Intakes.

Maximizing the post-exercise increase in muscle protein synthesis, especially of the contractile myofibrillar protein fraction, is essential to facilitate effective muscle remodeling, and enhance hypertrophic gains with resistance training. MPS is the primary regulated variable influencing muscle net balance with dietary amino acid ingestion representing the single most important nutritional variable enhancing post-exercise rates of muscle protein synthesis. Dose-response studies in average (i.e., ~80 kg) males have reported an absolute 20 g dose of high quality, rapidly digested protein maximizes mixed, and myofibrillar protein synthetic rates. However, it is unclear if these absolute protein intakes can be viewed in a “one size fits all” solution. Re-analysis of published literature in young adults suggests a relative single meal intake of ~0.31 g/kg of rapidly digested, high quality protein (i.e., whey) should be considered as a nutritional guideline for individuals of average body composition aiming to maximize post-exercise myofibrillar protein synthesis while minimizing irreversible amino acid oxidative catabolism that occurs with excessive intakes of this macronutrient. This muscle-specific bolus intake is lower than that reported to maximize whole body anabolism (i.e., ≥0.5 g/kg). Review of the available literature suggests that potential confounders such as the co-ingestion of carbohydrate, sex, and amount of active muscle mass do not represent significant barriers to the translation of this objectively determined relative protein intake. Additional research is warranted to elucidate the effective dose for proteins with suboptimal amino acid compositions (e.g., plant-based), and/or slower digestion rates as well as whether recommendations are appreciably affected by other physiological conditions such endurance exercise, high habitual daily protein ingestion, aging, obesity, and/or periods of chronic negative energy balance.

Carbohydrate and Caffeine Improves High-Intensity Running of Elite Rugby League Interchange Players During Simulated Match Play.

Clarke, JS, Highton, J, Close, GL, and Twist, C. Carbohydrate and caffeine improves high-intensity running of elite rugby league interchange players during simulated match play. J Strength Cond Res 33(5): 1320-1327, 2019-The study examined the effects of carbohydrate and caffeine ingestion on simulated rugby league interchange performance. Eight male elite rugby league forwards completed 2 trials of a rugby league simulation protocol for interchange players 7 days apart in a randomized crossover design, ingesting either carbohydrate (CHO; 40 g·h) or carbohydrate and caffeine (CHO-C) (40 g·h + 3 mg·kg) drink. Movement characteristics, heart rate, ratings of perceived exertion (RPE), and countermovement jump (CMJ) height were measured during the protocol. CHO-C resulted in likely to very likely higher mean running speeds (effect size [ES] 0.43-0.75), distance in high-intensity running (ES 0.41-0.64), and mean sprint speeds (ES 0.39-1.04) compared with CHO. Heart rate was possibly to very likely higher (ES 0.32-0.74), and RPE was likely to very likely lower (ES -0.53 to 0.86) with CHO-C. There was a likely trivial to possibly higher CMJ in CHO-C compared with CHO (ES 0.07-0.25). The coingestion of carbohydrate with caffeine has an ergogenic effect to reduce the sense of effort and increase high-intensity running capability that might be used to enhance interchange running performance in elite rugby league players.

Myofibrillar and Mitochondrial Protein Synthesis Rates Do Not Differ in Young Men Following the Ingestion of Carbohydrate with Whey, Soy, or Leucine-Enriched Soy Protein after Concurrent Resistance- and Endurance-Type Exercise

ABSTRACTBackgroundProtein ingestion during recovery from resistance-type exercise increases postexercise muscle protein synthesis rates. Whey protein has been reported to have greater anabolic properties than soy protein, an effect which may be attributed to the higher leucine content of whey.ObjectiveThe objective of this study was to compare postprandial myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis rates after ingestion of carbohydrate with whey, soy, or soy protein enriched with free leucine (to match the leucine content of whey) during recovery from a single bout of concurrent resistance- and endurance-type exercise in young healthy men.MethodsIn a randomized, double-blind, parallel-group design, 36 healthy young recreationally active men (mean ± SEM age: 23 ± 0.4 y) received a primed continuous infusion of l-[ring-13C6]-phenylalanine and l-[ring-3,5-2H2]-tyrosine and ingested 45 g carbohydrate with 20 g protein from whey (WHEY), soy (SOY), or leucine-enriched soy (SOY + LEU) after concurrent resistance- and endurance-type exercise. Blood and muscle biopsies were collected over a 360 min postexercise recovery period to assess MyoPS and MitoPS rates, and associated signaling through the mammalian target of rapamycin complex 1 (mTORC1).ResultsPostprandial peak plasma leucine concentrations were significantly higher in WHEY (mean ± SEM: 322 ± 10 μmol/L) and SOY + LEU (328 ± 14 μmol/L) compared with SOY (216 ± 6 μmol/L) (P < 0.05). Despite the apparent differences in plasma leucinemia, MyoPS (WHEY: 0.054 ± 0.002; SOY: 0.053 ± 0.004; SOY + LEU: 0.056 ± 0.004%·h−1; P = 0.83), and MitoPS (WHEY: 0.061 ± 0.004; SOY: 0.061 ± 0.006; SOY + LEU: 0.063 ± 0.004%·h−1; P = 0.96) rates over the entire 360 min recovery period did not differ between treatments. Similarly, signaling through mTORC1Ser2448, p70S6kThr389, 4E-BP1Thr37/46, and rpS6Ser235/236 was similar between treatments.ConclusionPostexercise MyoPS and MitoPS rates do not differ after co-ingestion of carbohydrate with 20 g protein from whey, soy, or leucine-enriched soy protein during 360 min of recovery from concurrent resistance- and endurance-type exercise in young, recreationally active men. This trial was registered at Nederlands Trial Register as NTR5098.

Effect of carbohydrate and protein solutions consumed during a moderate-intensity exercise on post-exercise appetite

This study aimed to investigate whether co-ingestion of carbohydrate and protein during exercise affect the post-exercise ad libitum food intake. Twelve healthy active male participants (mean±SD, age: 20±1; height: 176±6cm; weight: 63.6±5.3kg; VO2peak: 51.2±7.1ml/kg/min) completed three main experimental trials in a randomized cross-over design. In each trial, the participants completed 1h of ergometer cycling at 60% VO2peak, followed by 2h recovery. The participants were required to consume one of three solutions every 15min during exercise: distilled water (DW), carbohydrate-electrolyte solution (CE), and carbohydrate-electrolyte-protein solution (CEP). The energy was matched between the two latter solutions. The CHO-to-protein ratio in CEP was 2:1. At the end of recovery period, participants were provided with pizza lunch ad libitum, and the amount consumed was recorded. Several subjective feelings, appetite scores and blood glucose were determined during the experimental trials. No differences were found in either the amount of consumed pizza (DW vs. CE vs. CEP: 607±128 vs. 592±119 vs. 599±125g, P=0.845) or the appetite score before pizza was consumed (DW vs. CE vs. CEP: 14±9 vs. 12±14 vs. 14±10, P=0.357) among the three trials. The blood glucose concentrations during exercise were higher in the CE and CEP trials than in the DW trial. In conclusion, different solutions consumed during a 1h moderate-intensity exercise in the present study did not affect post-exercise appetite.

Co-ingestion of carbohydrate and whey protein increases fasted rates of muscle protein synthesis immediately after resistance exercise in rats.

The objective of the study was to investigate whether co-ingestion of carbohydrate and protein as compared with protein alone augments muscle protein synthesis (MPS) during early exercise recovery. Two months old rats performed 10 repetitions of ladder climbing with 75% of body weight attached to their tails. Placebo (PLA), whey protein (WP), or whey protein plus carbohydrate (CP) was then given to rats by gavage. An additional group of sedentary rats (SED) was used as controls. Blood samples were collected immediately and at either 1 or 2 h after exercise. The flexor hallucis longus muscle was excised at 1 or 2 h post exercise for analysis of MPS and related signaling proteins. MPS was significantly increased by CP compared with PLA (p<0.05), and approached significance compared with WP at 1 h post exercise (p = 0.08). CP yielded a greater phosphorylation of mTOR compared with SED and PLA at 1 h post exercise and SED and WP at 2 h post exercise. CP also increased phosphorylation of p70S6K compared with SED at 1 and 2 h post exercise. 4E-BP1 phosphorylation was inhibited by PLA at 1 h but elevated by WP and CP at 2 h post exercise relative to SED. The phosphorylation of AMPK was elevated by exercise at 1 h post exercise, and this elevated level was sustained only in the WP group at 2 h. The phosphorylation of Akt, GSK3, and eIF2Bε were unchanged by treatments. Plasma insulin was transiently increased by CP at 1 h post exercise. In conclusion, post-exercise CP supplementation increases MPS post exercise relative to PLA and possibly WP, which may have been mediated by greater activation of the mTOR signaling pathway.

Muscle Carnosine Concentration with the Co-Ingestion of Carbohydrate with β-alanine in Male Rats

ABSTRACTMuscle carnosine is an intracellular buffer. The intake of β-alanine, combined with carbohydrate and protein, enhanced carnosine loading in human muscle. The aim of the present study was to examine if muscle carnosine loading was enhanced by β-alanine intake and co-ingestion of glucose in male rats. Thirty-six male rats were divided into three groups and supplemented for four weeks: β-alanine (βA group, 1.8% β-alanine in drinking water), β-alanine and glucose (βAGL group, 1.8% β-alanine and 5% glucose in drinking water), and control (C group, drinking water). During the supplementation period, rats were exercised (20 m·min−1, 10 min·day−1, 4 days·week−1 for 4 weeks). Muscle carnosine concentration was quantified in soleus (n = 12) and rectus femoris (n = 6) muscles using high-performance liquid chromatography. In soleus muscle, carnosine concentration was 2.24 ± 1.10, 6.12 ± 1.08, and 6.93 ± 2.56 mmol/kg dw for control, βA, and βAGL, respectively. In rectus femoris, carnosine concentration was 2.26 ± 1.31, 7.90 ± 1.66, and 8.59 ± 2.33 mmol/kg dw for control, βA, and βAGL respectively. In each muscle, βA and βAGL resulted in similar carnosine increases compared to the control. In conclusion, β-alanine intake for four weeks, either alone or with glucose co-ingestion, equally increased muscle carnosine content. It appears that the potential insulin response to fluid glucose intake does not affect muscle carnosine loading in male rats.

Co-ingestion of carbohydrate with leucine-enriched essential amino acids does not augment acute postexercise muscle protein synthesis in a strenuous exercise-induced hypoinsulinemic state.

Strenuous exercise following overnight fasting increases fat oxidation during exercise, which can modulate training adaptation. However, such exercise induces muscle protein catabolism by decreasing blood insulin concentrations and increasing amino acid oxidation during the exercise. Leucine-enriched essential amino acids (LEAAs) enhance muscle protein synthesis (MPS) at rest and after exercise. However, it remains to be clarified if the co-ingestion of carbohydrate with LEAAs induces an additional increase in MPS, particularly in a hypoinsulinemic state induced by strenuous exercise. Eight-week-old male Sprague–Dawley rats were made to perform strenuous jump exercise (height 35 cm, 200 jumps, 3-s intervals), after which they ingested distilled water and 1 g/kg LEAAs with or without 1 g/kg of glucose. The fractional synthesis rate was determined by measuring the incorporation of l-[ring-2H5]-phenylalanine into skeletal muscle protein. Immediately after the exercise, plasma insulin concentration was significantly lower than that at the basal level. Co-ingestion of glucose with LEAAs alleviated the reduction in plasma insulin concentration, while LEAA ingestion alone did not. LEAA administration with or without glucose led to a higher MPS compared with water administration (P < 0.05). However, the co-ingestion of glucose with LEAAs did not induce further increases in MPS compared with LEAA ingestion alone. Thus, the co-ingestion of glucose with LEAAs does not additionally increase MPS under a strenuous exercise–induced hypoinsulinemic state when glucose is co-ingested with a dose of LEAAs that maximally stimulates MPS.

Effects Of A Nutritive Administration Of Carbohydrates And Protein By Food On Skeletal Muscle Inflammation And Damage After Acute Endurance Exercise

: Scientific Background: Protein ingestion has been recently described to enhance the effects of carbohydrate drinks on skeletal muscle recovery. The aim of this study was to investigate the beneficial effects of a co-ingestion of carbohydrate and protein by food in amateur sportsmen. METHODS: 16 male subjects performed a 10km run at 80% of individual ANS. Immediately after exercise subjects ingest either nothing (control), carbohydrates by eating white bread, or a combination of carbohydrates and protein by eating white bread and a sour milk cheese. Blood samples were taken at different time points. Serum glucose, serum insulin, serum creatine kinase (CK) and the serum levels of IL6, IL 10, MIF and TNF alpha were determined. RESULTS: Blood glucose was increased by endurance exercise. Blood glucose levels decreased rapidly after exercise, here the strongest decrease could be observed in the bread/cheese group. Food uptake results in strong increase of serum insulin not differing between bread and bread/cheese. CK serum levels as a marker for skeletal muscle damage strongly increased 24h after exercise in the control and bread group but not in the bread cheese group. Exercise resulted in an increase of serum IL 6 and MIF which was reduced in the bread/cheese group. Serum IL 10 was increased by bread/cheese ingestion. TNF alpha serum concentration was decreased by exercise. This decrease was antagonized by bread/cheese ingestion. CONCLUSION: Our data demonstrate that uptake of a combination of protein and carbohydrate by food immediately after endurance exercise effect’s physiological responses like blood glucose levels of the individual’s and antagonize the induction of serum CK, a marker of skeletal muscle damage. Moreover this nutritive carbohydrate/protein uptake seems to influence the inflammatory response of the skeletal muscle indicated by reduced concentrations of proinflammatory markers and an increase of anti-inflammatory markers.

Editorial: Post-Exercise Recovery: Fundamental and Interventional Physiology.

Editorial: Post-Exercise Recovery: Fundamental and Interventional Physiology.

The acute effects of green tea and carbohydrate coingestion on systemic inflammation and oxidative stress during sprint cycling.

Green tea (Camellia sinensis) has anti-oxidative and anti-inflammatory effects, which may be beneficial to athletes performing high-intensity exercise. This study investigated the effects of carbohydrate and green tea coingestion on sprint cycling performance and associated oxidative stress and immunoendocrine responses to exercise. In a crossover design, 9 well-trained male cyclists completed 3 sets of 8 repetitions of 100-m uphill sprint cycling while ingesting green tea and carbohydrate (TEA) (22 mg/kg body mass catechins, 6 mg/kg body mass caffeine, 230 mg/kg glucose, and 110 mg/kg fructose) or carbohydrate only (CHO) (230 mg/kg body mass glucose and 110 mg/kg body mass fructose) during each 10-min recovery period between sets. Blood samples were collected before exercise, 10 min after exercise, and 14 h after exercise. There was no effect of acute TEA ingestion on cycling sprint performance (p = 0.29), although TEA maintained postexercise testosterone and lymphocyte concentrations, which decreased significantly in the CHO group (p < 0.001). While there was a trend for lower postexercise neutrophil count with TEA (p = 0.05), there were no significant differences between TEA and CHO for circulating cytokines (p > 0.20), markers of oxidative stress and antioxidant capacity (p > 0.17), adiponectin concentration (p = 0.60), or muscle damage markers (p > 0.64). While acute green tea ingestion prevents the postexercise decrease in testosterone and lymphocytes, it does not appear to benefit cycling sprint performance or reduce markers of oxidation and inflammation when compared with carbohydrate alone.

Impact of the Macronutrient Composition of a Nutritional Supplement on Muscle Protein Synthesis Rates in Older Men: A Randomized, Double Blind, Controlled Trial.

An impaired muscle protein synthetic response to feeding likely contributes to muscle loss with aging. There are few data available on the effect of the macronutrient composition of clinical supplements on the postprandial muscle protein synthetic response in older subjects. The objective of the study was to determine the impact of the macronutrient composition of a nutritional supplement on the postprandial muscle protein synthetic response in older men. A total of 45 nonsarcopenic older men (aged 69 ± 1 y; body mass index 25.7 ± 0.3 kg/m(2)) were randomly assigned to ingest 21 g of leucine-enriched whey protein with carbohydrate (9 g) and fat (3 g) (Pro-En), an isonitrogenous amount of 21 g of leucine-enriched whey protein without carbohydrate and fat (Pro), or an isocaloric mixture (628 kJ) containing carbohydrate and fat only (En). Stable isotope tracer methodology was applied to assess the basal as well as the postprandial muscle protein synthesis rates in the three groups. Ingestion of protein in the Pro-En and Pro groups significantly increased muscle protein synthesis rates when compared with the basal rates (from 0.032 ± 0.003%/h to 0.05%/h 3 ± 0.004%/h and 0.040%/h ± 0.003%/h to 0.049%/h ± 0.003%/h, respectively; P < .05), whereas ingestion of carbohydrate and fat did not increase muscle protein synthesis rates in the En group (from 0.039%/h ± 0.004%/h to 0.040%/h ± 0.003%/h; P = .60). Despite the greater postprandial rise in circulating insulin concentration in the Pro-En group, no significant differences were observed in postprandial muscle protein synthesis rates between the Pro-En and Pro groups (P = .32). Postprandial muscle protein synthesis rates were higher in the Pro-En vs En group (P = .01). The ingestion of a nutritional supplement containing 21 g of leucine-enriched whey protein significantly raises muscle protein synthesis rates in nonsarcopenic older men, but coingestion of carbohydrate and fat does not modulate the postprandial muscle protein synthetic response to protein ingestion in older men.

Co-ingestion of carbohydrate with branched-chain amino acids or L-leucine does not preferentially increase serum IGF-1 and expression of myogenic-related genes in response to a single bout of resistance exercise.

The purpose of this study was to determine if the co-ingestion of carbohydrate (CHO) with branched-chain amino acids (BCAA) or L-leucine (LEU) preferentially affected serum IGF-1 and the expression of myogenic-related genes in response to resistance exercise (RE). Forty-one college-age males were randomly assigned to 1 of 4 groups: CHO, CHO-BCAA, CHO-LEU, or placebo (PLC). Resistance exercise consisted of 4 sets of 10 repetitions of leg press and leg extension at 80 % 1RM. Supplements were ingested peri-exercise, and venous blood and muscle biopsies were obtained pre-exercise (PRE), and at 30, 120, and 360 min post-exercise. Serum IGF-1 was determined with ELISA, and skeletal muscle mRNA expression of myostatin, ACTRIIB, p21kip, p27kip, CDK2, cyclin B1, cyclin D1, Myo-D, myogenin, MRF-4, and myf5 was determined using real-time PCR. Results were analyzed by two-way ANOVA for serum IGF-1 and two-way MANOVA for mRNA expression. Serum IGF-1 in CHO + BCAA was greater than PLC (p < 0.05) but was not affected by RE (p > 0.05). A significant group × time interaction was located for cylin D1 (p < 0.05), but not for any other genes. However, significant time effects were noted for cyclin B1 and p21cip (p < 0.05). At 30, 120 and 360 min post-exercise, p21cip was significantly less than PRE. Cyclin D1 was greater than PRE and 30 min post-exercise at 120 and 360 min post-exercise, whereas cyclin B1 was significantly greater than PRE at 120 min post-exercise (p < 0.05). Unlike the co-ingestion of CHO with either BCAA or L-leucine in conjunction with RE, the expression of various myogenically related genes were up-regulated with RE.

Co-ingestion of carbohydrate and pea protein does not enhance muscle recovery after strenuous exercise

OBJECTIVE: To assess the influence of carbohydrate and added pea protein concentrate supplementation on muscle recovery after a military operation called Leader's Reaction Test. METHODS: Twenty-four soldiers from the Brazilian Army were divided into three equal groups (n=8). They received either carbohydrate (0.8.g/kg body weight/h), carbohydrate+carbohydrate (1.0.g/kg body weight/h), or carbohydrate+protein (0.8 g/kg body weight/h of carbohydrate + 0.2 g/kg body weight/h of protein), immediately, 60, and 120 minutes after the Leader’s Reaction Test. Prior, immediately after and 24 hours after the Leader’s Reaction Test, maximal isometric strength and body composition were assessed. Blood samples were also collected for later analysis of concentrations of lactate dehydrogenase and creatine kinase. RESULTS: Twenty-four hours after the Leader's Reaction Test, maximal creatine kinase levels were significantly lower than its levels immediately after (501.00 ± 422.09 versus 275.29 ± 242.08 U/L (carbohydrate); 616.88 ± 291.45 versus 334.57 ± 191.61 U/L (carbohydrate+carbohydrate); and 636.75 ± 340.67 versus 382.88 ± 234.42 U/L (carbohydrate+protein), p=0.004). The maximal isometric strength and lactate dehydrogenase levels were not significantly different during the time trials. CONCLUSION: The present findings suggest that carbohydrate+protein co-ingestion did not improve the recovery of muscle function nor did it attenuate post-exercise muscle damage markers over carbohydrate alone.

Carbohydrate Coingestion Delays Dietary Protein Digestion and Absorption but Does Not Modulate Postprandial Muscle Protein Accretion

Dietary protein digestion and absorption is an important factor modulating muscle protein accretion. However, there are few data available on the effects of coingesting other macronutrients with protein on digestion and absorption kinetics and the subsequent muscle protein synthetic response. The objective of the study was to determine the impact of carbohydrate coingestion with protein on dietary protein digestion and absorption and muscle protein accretion in healthy young and older men. Twenty-four healthy young (aged 21± 1 y, body mass index 21.8 ±0.5 kg/m(2)) and 25 older (aged 75 ± 1 y, body mass index 25.4 ± 0.6 kg/m(2)) men received a primed continuous L-[ring-(2)H5]-phenylalanine and L-[ring-3,5-(2)H2]-tyrosine infusion and ingested 20 g intrinsically L-[1-(13)C]-phenylalanine-labeled protein with (Pro+CHO) or without (Pro) 60 g carbohydrate. Plasma samples and muscle biopsies were collected in a postabsorptive and postprandial state. Carbohydrate coingestion delayed the appearance of exogenous phenylalanine in the circulation (P = .001). Dietary protein-derived phenylalanine availability over the 5-hour postprandial period was lower in the older (62 ± 2%) when compared with the young subjects (74 ± 2%; P = .007), with no differences between conditions (P = .20). Carbohydrate coingestion did not modulate postprandial muscle protein synthesis rates (0.035 ± 0.003 vs 0.043 ± 0.004 and 0.033 ± 0.002 vs 0.035 ± 0.003%/h after Pro vs Pro+CHO in the young and older group, respectively). In accordance, no differences in muscle protein-bound L-[1-(13)C]-phenylalanine enrichments were observed between conditions (0.020 ± 0.002 vs 0.020 ± 0.002 and 0.019 ± 0.003 vs 0.022 ± 0.004 mole percent excess after Pro vs Pro+CHO in the young and older subjects, respectively). Carbohydrate coingestion with protein delays dietary protein digestion and absorption but does not modulate postprandial muscle protein accretion in healthy young or older men.