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The Science Behind Carbofuel Energy

Cadence CarboFuel Energy has been formulated to provide the energy and nutrient requirements for athletes training and racing over a variety of distances, particularly in hot conditions where fluid and electrolyte losses are high.

STATEMENT

Optimal balance of maltodextrin and fructose (2:1). Numerous studies show that combining fructose with maltodextrin improves exercise performance, maximises gastric emptying rate and increases fluid absorption rate, delaying fatigue and delaying the onset of dehydration.

SCIENCE

Am J Physiol Gastrointest Liver Physiol. 2011 Jan; 300(1): G181-9

Fructose-maltodextrin ratio in a carbohydrate-electrolyte solution differentially affects exogenous carbohydrate oxidation rate, gut comfort, and performance.

O’Brien WJ, Rowlands DS.

School of Sport and Exercise, Massey University, Wellington, New Zealand.

Solutions containing multiple carbohydrates utilizing different intestinal transporters (glucose and fructose) show enhanced absorption, oxidation, and performance compared with single-carbohydrate solutions, but the impact of the ratio of these carbohydrates on outcomes is unknown. In a randomized double-blind crossover, 10 cyclists rode 150 min at 50% peak power, then performed an incremental test to exhaustion, while ingesting artificially sweetened water or one of three carbohydrate-salt solutions comprising fructose and maltodextrin in the respective following concentrations: 4.5 and 9% (0.5-Ratio), 6 and 7.5% (0.8-Ratio), and 7.5 and 6% (1.25-Ratio). The carbohydrates were ingested at 1.8 g/min and naturally (13)C-enriched to permit evaluation of oxidation rate by mass spectrometry and indirect calorimetry. Mean exogenous carbohydrate oxidation rates were 1.04, 1.14, and 1.05 g/min (coefficient of variation 20%) in 0.5-, 0.8-, and 1.25-Ratios, respectively, representing likely small increases in 0.8-Ratio of 11% (90% confidence limits; ± 4%) and 10% (± 4%) relative to 0.5- and 1.25-Ratios, respectively. Comparisons of fat and total and endogenous carbohydrate oxidation rates between solutions were unclear. Relative to 0.5-Ratio, there were moderate improvements to peak power with 0.8- (3.6%; 99% confidence limits ± 3.5%) and 1.25-Ratio (3.0%; ± 3.7%) but unclear with water (0.4%; ± 4.4%). Increases in stomach fullness, abdominal cramping, and nausea were lowest with the 0.8- followed by the 1.25-Ratio solution. At high carbohydrate-ingestion rate, greater benefits to endurance performance may result from ingestion of 0.8- to 1.25-Ratio fructose-maltodextrin solutions. Small perceptible improvements in gut comfort favor the 0.8-Ratio and provide a clearer suggestion of mechanism than the relationship with exogenous carbohydrate oxidation.

Scand J Med Sci Sports. 2010 Feb;20(1):112-21

Multiple transportable carbohydrates enhance gastric emptying and fluid delivery.

Jeukendrup AE, Moseley L.

Human Performance Laboratory, Department of Exercise Metabolism, School of Sport and Exercise Sciences, The University of Birmingham, Edgbaston, Birmingham, UK.

This study compared the effects of ingesting water (WATER), an 8.6% glucose solution (GLU) and an 8.6% glucose+fructose solution (2:1 ratio, GLU+FRU) on gastric emptying (GE), fluid delivery, and markers of hydration status during moderate intensity exercise. Eight male subjects (age=24 +/- 2 years, weight=74.5 +/- 1.2 kg, VO(2max)=62.6 +/- 2.5 mL/kg/min) performed three 120 min cycling bouts at 61% VO(2max)). Subjects ingested GLU, GLU+FRU (both delivering 1.5 g/min carbohydrate), or WATER throughout exercise, ingesting 2.1 L. Serial dye dilution measurements of GE were made throughout exercise and subjects ingested 5.00 g of D(2)O and 150 mg of (13)C-acetate at 60 min to obtain measures of fluid uptake and GE, respectively. GLU+FRU resulted in faster rates of deuterium accumulation, an earlier time to peak in the (13)C enrichment of expired air and a faster rate of GE compared with GLU. GLU+FRU also attenuated the rise in heart rate that occurred in GLU and WATER and resulted in lower ratings of perceived exertion. There was a greater loss in body weight with GLU corrected for fluid intake. These data suggest that ingestion of a combined GLU+FRU solution increases GE and “fluid delivery” compared with a glucose only solution.

J Appl Physiol. 2008 Jun;104(6):1709-19. Epub 2008 Mar 27.

Effect of graded fructose coingestion with maltodextrin on exogenous 14C-fructose and 13C-glucose oxidation efficiency and high-intensity cycling performance.

Rowlands DS, Thorburn MS, Thorp RM, Broadbent S, Shi X.

Institute of Food, Nutrition, and Human Health, Massey Univ., Wellington, New Zealand. d.s.rowlands@massey.ac.nz

The ingestion of solutions containing carbohydrates with different intestinal transport mechanisms (e.g., fructose and glucose) produce greater carbohydrate and water absorption compared with single-carbohydrate solutions. However, the fructose-ingestion rate that results in the most efficient use of exogenous carbohydrate when glucose is ingested below absorption-oxidation saturation rates is unknown. Ten cyclists rode 2 h at 50% of peak power then performed 10 maximal sprints while ingesting solutions containing (13)C-maltodextrin at 0.6 g/min combined with (14)C-fructose at 0.0 (No-Fructose), 0.3 (Low-Fructose), 0.5 (Medium-Fructose), or 0.7 (High-Fructose) g/min, giving fructose:maltodextrin ratios of 0.5, 0. 8, and 1.2. Mean (percent coefficient of variation) exogenous-fructose oxidation rates during the 2-h rides were 0.18 (19), 0.27 (27), 0.36 (27) g/min in Low-Fructose, Medium-Fructose, and High-Fructose, respectively, with oxidation efficiencies (=oxidation/ingestion rate) of 62-52%. Exogenous-glucose oxidation was highest in Medium-Fructose at 0.57 (28) g/min (98% efficiency) compared with 0.54 (28), 0.48 (29), and 0.49 (19) in Low-Fructose, High-Fructose, No-Fructose, respectively; relative to No-Fructose, only the substantial 16% increase (95% confidence limits +/-16%) in Medium-Fructose was clear. Total exogenous-carbohydrate oxidation was highest in Medium-Fructose at 0.84 (26) g/min. Although the effect of fructose quantity on overall sprint power was unclear, the metabolic responses were associated with lower perceptions of muscle tiredness and physical exertion, and attenuated fatigue (power slope) in the Medium-Fructose and High-Fructose conditions. With the present solutions, low-medium fructose-ingestion rates produced the most efficient use of exogenous carbohydrate, but fatigue and the perception of exercise stress and nausea are reduced with moderate-high fructose doses.

Med Sci Sports Exerc. 2008 Feb;40(2):275-81.

Superior endurance performance with ingestion of multiple transportable carbohydrates.

Currell K, Jeukendrup AE.

Human Performance Laboratory, School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, UK.

The aim of the present study was to investigate the effect of ingesting a glucose plus fructose drink compared with a glucose-only drink (both delivering carbohydrate at a rate of 1.8 g.min(-1)) and a water placebo on endurance performance. METHODS: Eight male trained cyclists were recruited (age 32 +/- 7 yr, weight 84.4 +/- 6.9 kg, .VO(2max) 64.7 +/- 3.9 mL.kg(-1).min(-1), Wmax 364 +/- 31 W). Subjects ingested either a water placebo (P), a glucose (G)-only beverage (1.8 g.min(-1)), or a glucose and fructose (GF) beverage in a 2:1 ratio (1.8 g.min(-1)) during 120 min of cycling exercise at 55% Wmax followed by a time trial in which subjects had to complete a set amount of work as quickly as possible (approximately 1 h). Every 15 min, expired gases were analyzed and blood samples were collected. RESULTS: Ingestion of GF resulted in an 8% quicker time to completion during the time trial (4022 s) compared with G (3641 s) and a 19% improvement compared with W (3367 s). Total carbohydrate (CHO) oxidation was not different between GF (2.54 +/- 0.25 g.min(-1)) and G (2.50 g.min(-1)), suggesting that GF led to a sparing of endogenous CHO stores, because GF has been shown to have a greater exogenous CHO oxidation than G. CONCLUSION: Ingestion of GF led to an 8% improvement in cycling time-trial performance compared with ingestion of G.

J Appl Physiol. 2006 Apr;100(4):1134-41. Epub 2005 Dec 1.

Exogenous carbohydrate oxidation during ultraendurance exercise.

Jeukendrup AE, Moseley L, Mainwaring GI, Samuels S, Perry S, Mann CH.

Human Performance Laboratory, School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. A.E.Jeukendrup@bham.ac.uk

The purposes of this study were: 1) to obtain a measure of exogenous carbohydrate (CHO(Exo)) oxidation and plasma glucose kinetics during 5 h of exercise; and 2) to compare CHO(Exo) following the ingestion of a glucose solution (Glu) or a glucose + fructose solution (2:1 ratio, Glu+Fru) during ultraendurance exercise. Eight well-trained subjects exercised three times for 5 h at 58% maximum O2 consumption while ingesting either Glu or Glu+Fru (both delivering 1.5 g/min CHO) or water. The CHO used had a naturally high 13C enrichment, and five subjects received a primed continuous intravenous [6,6-2H2]glucose infusion. CHO(Exo) rates following the ingestion of Glu leveled off after 120 min and peaked at 1.24 +/- 0.04 g/min. The ingestion of Glu+Fru resulted in a significantly higher peak rate of CHO(Exo) (1.40 +/- 0.08 g/min), a faster rate of increase in CHO(Exo), and an increase in the percentage of CHO(Exo) oxidized (65-77%). However, the rate of appearance and disappearance of Glu continued to increase during exercise, with no differences between trials. These data suggest an important role for gluconeogenesis during the later stages of exercise. Following the ingestion of Glu+Fru, cadence (rpm) was maintained, and the perception of stomach fullness was reduced relative to Glu. The ingestion of Glu+Fru increases CHO(Exo) compared with the ingestion of Glu alone, potentially through the oxidation of CHO(Exo) in the liver or through the conversion to, and oxidation of, lactate.

STATEMENT

Magnesium is an essential element is energy metabolism and cell function. Dietary intake of magnesium is often insufficient in athletic populations. Physical exercise may deplete magnesium, which, together with a marginal dietary magnesium intake, may impair energy metabolism efficiency and the capacity for physical work as well as increasing immunosupression and oxidative damage caused by exercise.

SCIENCE

Crit Rev Food Sci Nutr. 2002;42(6):533-63.

Magnesium and exercise.

Bohl CH, Volpe SL.

University of Massachusetts, Department of Nutrition, Amherst 01003, USA.

Magnesium is an essential element that regulates membrane stability and neuromuscular, cardiovascular, immune, and hormonal functions and is a critical cofactor in many metabolic reactions. The Dietary Reference Intake for magnesium for adults is 310 to 420 mg/day. However, the intake of magnesium in humans is often suboptimal. Magnesium deficiency may lead to changes in gastrointestinal, cardiovascular, and neuromuscular function. Physical exercise may deplete magnesium, which, together with a marginal dietary magnesium intake, may impair energy metabolism efficiency and the capacity for physical work. Magnesium assessment has been a challenge because of the absence of an accurate and convenient assessment method. Recently, magnesium has been touted as an agent for increasing athletic performance. This article reviews the various studies that have been conducted to investigate the relationship of magnesium and exercise.

Magnes Res. 2006 Sep;19(3):180-9.

Update on the relationship between magnesium and exercise.

Nielsen FH, Lukaski HC.

U.S. Department ofAgriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202-9034, USA. fnielsen@gfhnrc.ars.usda.gov

Magnesium is involved in numerous processes that affect muscle function including oxygen uptake, energy production and electrolyte balance. Thus, the relationship between magnesium status and exercise has received significant research attention. This research has shown that exercise induces a redistribution of magnesium in the body to accommodate metabolic needs. There is evidence that marginal magnesium deficiency impairs exercise performance and amplifies the negative consequences of strenuous exercise (e.g., oxidative stress). Strenuous exercise apparently increases urinary and sweat losses that may increase magnesium requirements by 10-20%. Based on dietary surveys and recent human experiments, a magnesium intake less than 260 mg/day for male and 220 mg/day for female athletes may result in a magnesium-deficient status. Recent surveys also indicate that a significant number of individuals routinely have magnesium intakes that may result in a deficient status. Athletes participating in sports requiring weight control (e.g., wrestling, gymnastics) are apparently especially vulnerable to an inadequate magnesium status. Magnesium supplementation or increased dietary intake of magnesium will have beneficial effects on exercise performance in magnesium-deficient individuals. Magnesium supplementation of physically active individuals with adequate magnesium status has not been shown to enhance physical performance. An activity-linked RNI or RDA based on long-term balance data from well-controlled human experiments should be determined so that physically active individuals can ascertain whether they have a magnesium intake that may affect their performance or enhance their risk to adverse health consequences (e.g., immunosuppression, oxidative damage, arrhythmias).

STATEMENT

Balanced electrolyte formula to optimise performance, reduce the risk of hyponatraemia and prolong glucose absorption.

SCIENCE

Int J Sports Med. 1994 Oct;15(7):392-8.

Impaired high-intensity cycling performance time at low levels of dehydration.

Walsh RM, Noakes TD, Hawley JA, Dennis SC.

Medical Research Council/University of Cape Town Medical School, Department of Physiology, Observatory, South Africa.

On two separate occasions six trained subjects (peak oxygen consumption [VO2peak] 4.41/min) rode for 60 min at 70% of VO2peak and then to exhaustion at 90% of VO2peak to determine the effects of mild dehydration on high-intensity cycling performance time in the heat (32 degrees C, 60% relative humidity, wind speed 3 km/h). In one trial (F) subjects ingested a 400 ml bolus of 20 mmol/l NaCl immediately before, and then as repetitive 120 ml feedings every 10 min during the first 50 min of exercise. In the other trial they did not ingest fluid (NF) either before or during exercise. The order of testing was in a counter-balanced random sequence. For the first 60 min of exercise mean (+/- SD) VO2 (2.90 +/- 0.39 vs 2.93 +/- 0.38 l/min) and respiratory exchange ratio (RER; 0.95 +/- 0.03 vs 0.94 +/- 0.04) values were similar between F and NF trials. However, weight loss was significantly reduced during F compared to NF (0.16 +/- 0.39 vs 1.30 +/- 0.22 kg; p < 0.005) and high-intensity cycling time to exhaustion was significantly increased (9.8 +/- 3.9 vs 6.8 +/- 3.0 min; p < 0.005). Increased cycling times to exhaustion in the F trial were not associated with any measurable differences in heart rate (HR), body temperature, respiratory gas exchange, leg muscle power over 5 sec, or the degree to which fluid ingestion reduced the level of dehydration within the group. Only the ratings of perceived exertion (RPE) and plasma anti diuretic hormone (ADH) concentrations were significantly increased in the NF trial compared to the F trial.(

J Appl Physiol. 1999 Jun;86(6):1847-51.

Sodium-free fluid ingestion decreases plasma sodium during exercise in the heat.

Vrijens DM, Rehrer NJ.

School of Physical Education, Otago University, Dunedin, New Zealand.

This study assessed whether replacing sweat losses with sodium-free fluid can lower the plasma sodium concentration and thereby precipitate the development of hyponatremia. Ten male endurance athletes participated in one 1-h exercise pretrial to estimate fluid needs and two 3-h experimental trials on a cycle ergometer at 55% of maximum O2 consumption at 34 degrees C and 65% relative humidity. In the experimental trials, fluid loss was replaced by distilled water (W) or a sodium-containing (18 mmol/l) sports drink, Gatorade (G). Six subjects did not complete 3 h in trial W, and four did not complete 3 h in trial G. The rate of change in plasma sodium concentration in all subjects, regardless of exercise time completed, was greater with W than with G (-2.48 +/- 2.25 vs. -0.86 +/- 1.61 mmol. l-1. h-1, P = 0.0198). One subject developed hyponatremia (plasma sodium 128 mmol/l) at exhaustion (2.5 h) in the W trial. A decrease in sodium concentration was correlated with decreased exercise time (R = 0.674; P = 0.022). A lower rate of urine production correlated with a greater rate of sodium decrease (R = -0. 478; P = 0.0447). Sweat production was not significantly correlated with plasma sodium reduction. The results show that decreased plasma sodium concentration can result from replacement of sweat losses with plain W, when sweat losses are large, and can precipitate the development of hyponatremia, particularly in individuals who have a decreased urine production during exercise. Exercise performance is also reduced with a decrease in plasma sodium concentration. We, therefore, recommend consumption of a sodium-containing beverage to compensate for large sweat losses incurred during exercise.

Br J Sports Med. 2003 Aug;37(4):300-3; discussion 303.

Effects of different sodium concentrations in replacement fluids during prolonged exercise in women.

Twerenbold R, Knechtle B, Kakebeeke TH, Eser P, Müller G, von Arx P, Knecht H.

Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland.

OBJECTIVE: To investigate the effect of different sodium concentrations in replacement fluids on haematological variables and endurance performance during prolonged exercise. METHODS: Thirteen female endurance athletes completed three four hour runs on a 400 m track. Environmental conditions differed between the three trials: 5.3 degrees C and snow (trial 1), 19.0 degrees C and sunny weather (trial 2), 13.9 degrees C and precipitation (trial 3). They consumed 1 litre of fluid an hour during the trials with randomised intake of fluids: one trial (H) with high sodium concentration (680 mg/l), one trial (L) with low sodium concentration (410 mg/l), and one trial with only water (W). Before and after the trials, subjects were weighed and blood samples were taken for analysis of [Na(+)](plasma), packed cell volume, and mean corpuscular volume. RESULTS: The mean (SD) decrease in [Na(+)](plasma) over the whole trial was significantly (p<0.001) less in trial H (2.5 (2.5) mmol/l) than in trial W (6.2 (2.1) mmol/l). Mild hyponatraemia ([Na(+)](plasma) = 130-135 mmol/l) was observed in only six women (46%) in trial H compared with nine (69%) in trial L, and 12 (92%) in trial W. Two subjects (17%) in trial W developed severe hyponatraemia ([Na(+)](plasma)<130 mmol/l). No significant differences were found in performance or haematological variables with the three different fluids. There was no significant correlation between[Na(+)](plasma) after the run and performance. There was a significant correlation between changes in [Na(+)](plasma) and changes in body weight. CONCLUSIONS: Exercise induced hyponatraemia in women is likely to develop from fluid overload during prolonged exercise. This can be minimised by the use of replacement fluids of high sodium concentration. Sodium replacement of at least 680 mg/h is recommended for women in a state of fluid overload during endurance exercise of four hours. However, higher [Na(+)](plasma) after the run and smaller decreases in [Na(+)](plasma) during the trials were no indication of better performance over four hours.

Exerc Sport Sci Rev. 2001 Jul;29(3):113-7.

Hyponatremia associated with exercise: risk factors and pathogenesis.

Montain SJ, Sawka MN, Wenger CB.

Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA. scott.montain@na.amedd.army.mil.

Exercise-related hyponatremia is an infrequent but potentially life-threatening accompaniment of prolonged exercise. This condition results from sodium losses in sweat, excessive water intake, or both. We review the risk factors for development of this condition and discuss evidence that there is a population at increased risk of hyponatremia during prolonged exercise.

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