Clinical Studies
Recent studies have shown the benefits of a 4:1 ratio of carbohydrate to protein found in both Accelerade sports drink and energy gel Accel Gel®. We've summed them up here. So, feel free to check them out to learn why Accelerade rehydrates and why both the liquid and the gel speed recovery and put you on the road to more endurance.
The results of this study found that "sprint performance is significantly improved when a carbohydrate/protein supplement is ingested during repeated bouts of short duration, high intensity cycling." The purpose of this study was whether or not a supplement with a carbohydrate-protein ratio of 4:1 would significantly improve sprint time in repeated bouts of high intensity cycling compared to placebo ingestion. Seventeen subjects completed a series of four x 2 km time trials on a cycle ergometer at a load corresponding to their lactate threshold. They ingested 354 mL of either Accelerade® or a flavored placebo 15 minutes prior to their first sprint, 472 mL after the second sprint, and 295 mL after the second and third sprint. A 60 minute rest interval was provided after the first sprint, while 30 minutes separated the remaining sprints. The Accelerade® treatment had an average finishing time of 177 +/- 12.1 sec while the placebo group finished with an average of 181 +/- 10.5 sec. Additionally, the last sprint was statistically faster for Accelerade vs. placebo. The 4th sprint in the Accelerade trial slowed by 2.4 sec from the 1st to the 4th sprint, whereas sprint time slowed by 6.8 sec from the 1st to the 4th sprint for placebo. Blood glucose was greater (p<0.05) for Accelerade® than placebo at pre and post 3rd and 4th sprints. These results indicate that if the 4.4 sec time differential was converted to distance it would mean finishing approximately 50 meters ahead of the next cyclist.
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This study found that "a [carbohydrate-protein] beverage consumed during exercise reduced lactate accumulation and perceived exertion compared to [carbohydrate-only] beverages ... and that "there are metabolic and performance advantages of [carbohydrate-protein] beverages over [carbohydrate-only beverages matched for either total calories or carbohydrate]." Ten male cyclists completed prolonged bouts of stationary cycling while consuming 250 mL of either a carbohydrate-protein beverage (Accelerade), a carbohydrate-only beverage with the same number of total calories as Accelerade or a carbohydrate-only beverage with the same amount of carbohydrate as Accelerade but fewer calories. The test was repeated every five to 10 days until all of the subjects had used all three beverages. Metabolic measures were assessed following 30 minutes of exercise. Blood lactate levels and heart rate were significantly lower in the Accelerade trial than in either of the carbohydrate-only beverage trials.
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This study found that "muscle recovery ... was enhanced with the ingestion of a [carbohydrate-protein] recovery beverage compared to a [carbohydrate-only] recovery beverage." Twenty-three NCAA Division I cross-country runners completed traditional in-season training for six days. Immediately following each training session, subjects ingested either a carbohydrate-protein beverage (Accelerade) or a carbohydrate-only beverage. Following a 21-day washout period, subjects repeated the same protocol as above, receiving the alternate beverage. Measurements of muscle damage (CPK) and muscle soreness were obtained before and after each trial. Compared to the carbohydrate-only, Accelerade reduced muscle damage by an average of 27 % and muscle soreness by 30 % in the runners.
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This study concluded that "combined data from three studies revealed significant improvements in performance ... with [carbohydrate-protein] versus [carbohydrate-only] supplementation." Heart rate (HR), rating of perceived exertion (RPE), and lactate were lower in the carbohydrate-protein trials, and "decreases in HR and RPE were associated with improvements in performance." Data from previous studies showing a 19 % average improvement in endurance performance with a carbohydrate-protein beverage (Accelerade) compared to a carbohydrate-only beverage were reexamined to determine if the improvement was related to any physiological variables that were measured. The analysis revealed that heart rate, perceived exertion, and blood lactate levels were lower in the carbohydrate-protein trials, although only decreases in heart rate and perceived exertion were associated with improvements in performance.
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This study showed that "a carbohydrate-protein beverage consumed during exercise attenuates post-exercise muscle damage, and improves subsequent muscle functioning compared to a placebo, or carbohydrate beverages matched for either carbohydrate or total calories." Twelve male cyclists performed four rides to exhaustion on a cycle ergometer. During the trials, subjects consumed 250 mL of either a carbohydrate-protein sports drink (Accelerade), a carbohydrate-only beverage with the same number of total calories as Accelerade, a carbohydrate-only beverage with the same amount of carbohydrate as Accelerade but fewer calories, or a non-caloric flavored placebo every 15 minutes. Exercise sessions were repeated every five to 10 days until each cyclist had used each of the four beverages. Measurements of muscle damage biomarkers (CPK and LDH) were taken before and after cycling. In addition, post-exercise muscle function was assessed one day post-exercise by recording the maximum number of leg extensions each subject could perform. On average, cyclists exhibited significantly lower levels of muscle damage markers and were able to perform significantly more leg extensions after riding with Accelerade than with any of the other beverages.
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This study concluded that "contrary to popular misconception, adding protein to a carbohydrate-based sports drink ... led to improved water retention by 15 % over [a carbohydrate-only sports drink] and 40 % over plain water." Cyclists exercised until they lost 2 % of their body weight (through sweating) and then drank either a carbohydrate-protein sports drink (Accelerade), a carbohydrate-only sports drink (Gatorade®), or water. Over the next three hours, measurements were taken to determine how much of each beverage was retained in the body (versus the amount lost through urination). The carbohydrate-protein sports drink was found to rehydrate the athletes 15 % better than the carbohydrate-only sports drink and 40 % better than water. All three drinks emptied from the stomach and were absorbed through the intestine at the same rate. In addition, there was no difference between the carbohydrate-protein drink and the carbohydrate-only drink in terms of effects on blood plasma volume. This suggests that the carbohydrate-protein drink resulted in increased water retention within and between cells. Therefore a carbohydrate-protein sports drink may be a preferable choice, over plain water and a carbohydrate-electrolyte sports drink, when rehydration and fluid retention are a concern.
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This study demonstrated that "ingestion of a carbohydrate-protein beverage minimized muscle damage indices during skiing compared to placebo and no fluid." Thirty-one recreational skiers were separated into three groups. All three groups skied 12 runs, which took about three hours. One group drank nothing. A second group drank 6 ounces of a placebo (flavored water) after every second run. A third group drank an equal amount of the carbohydrate-protein sports drink (Accelerade). After the 12th run, blood samples were taken from each skier and analyzed for two biomarkers of muscle stress (myoglobin and creatine kinase). Subjects that received the carbohydrate-protein sports drink showed no signs of muscle damage, while indicators of muscle damage increased by 49 % in subjects receiving only water.
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This study involving cyclists found that "post-exercise muscle damage was notably attenuated by [carbohydrate-protein] beverage administration in the majority of cyclists, and that "Cyclists who experienced large reductions in [muscle damage] following [carbohydrate-protein] treatments performed significantly better during subsequent exercise than non-responders." Fourteen recreationally competitive male cyclists rode stationary bikes to exhaustion. Subjects consumed either a carbohydrate-only sports drink or carbohydrate-protein sports drink (Accelerade) every 15 minutes of exercise, and within 30 minutes of exercise completion. Fifteen hours later, subjects had blood samples taken to assess plasma CPK levels (a marker of muscle damage), and then performed a second ride to exhaustion. The majority of subjects experienced large attenuations in CPK during the carbohydrate-protein trial versus the carbohydrate-only trial. The remaining five cyclists were "non-responders." To determine whether differences in post-exercise CPK responses influenced subsequent cycling endurance, performance was compared between the two groups during the second ride using a dependent t-test. The difference in time to exhaustion was significantly larger (p<.05) in the responder group than the non-responder group.
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This study demonstrated that "a carbohydrate beverage with additional protein calories produced significant improvements in time to fatigue and reductions in muscle damage in endurance athletes" compared to a carbohydrate-only beverage. Fifteen male cyclists rode stationary bicycles to exhaustion while drinking either a carbohydrate-protein sports drink (Accelerade) or a conventional carbohydrate sports drink (Gatorade). The following day, the cyclists completed a second ride to exhaustion at a higher intensity. The athletes were able to ride 29 % longer in the first workout and 40 % longer in the second workout when given the carbohydrate-protein drink than when given Gatorade. Blood samples were taken from the cyclists and tested for signs of muscle damage (CPK). The results revealed that the carbohydrate-protein sports drink reduced muscle damage by 83 % compared to the conventional carbohydrate sports drink.
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This study proved that "performance in high intensity, short duration activities can be enhanced with a [carbohydrate-protein sports drink]." The subjects were five collegiate male hockey players (one goalie and four skaters). Skaters ingested either a carbohydrate-protein sports drink (Accelerade) or a non-caloric placebo during two 90-minute practice days. Treatments were then switched for the following week. Shooting was assessed in skaters by shooting 25 pucks at targets at three-second intervals. Skating performance was measured by a time-to-complete task as players weaved through six cones while handling the puck. The goalie completed a skating drill of 10.5m and then an auditory/hand reaction time test using both hands. Performances were tested after practice on the second day. Speed performance improved by eight percent and reaction time improved by 12 % in the carbohydrate-protein sports drink treatment.
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This study demonstrated that "the addition of protein to a carbohydrate supplement enhanced aerobic endurance performance above that which occurred with carbohydrate alone." Trained cyclists exercised at various intensities for three hours, then they cycled at high intensity until they were exhausted. Every 20 minutes they drank either a carbohydrate-protein sports drink (Accelerade), a carbohydrate-only sports drink, or water. The carbohydrate-protein sports drink increased the amount of time the cyclists were able to continue pedaling by 36 % compared to the carbohydrate-only sports drink and by 55 % compared to water.
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This study showed that a carbohydrate-protein sports drink (Accelerade) improves sprinting speed at the end of a long soccer training session compared to a sports drink containing only electrolytes. Following an intense soccer workout of 75 minutes, subjects participated in four speed trials with five minutes of rest after each sprint. Half the players drank the carbohydrate-protein drink while the other half drank an electrolyte-only drink. The carbohydrate-protein group actually improved their speed by 1.1 seconds between the first and last sprints, while the other group slowed down by 2.2 seconds.
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This study showed that "A carbohydrate/protein energy gel improves swimming performance in collegiate swimmers." Twelve swimmers completed a workout consisting of a 15-minute warm-up, followed by a timed 200-yard freestyle, three sets of 8 x 100-yard freestyle (24 sprints total), and then a timed 200-yard swim. They received either a carbohydrate-protein energy gel (Accel Gel) or flavored water after the first 200-yard swim and again after each set of 100-yard sprints. They received four oz. of water with each gel. Each swimmer did the workout twice (on separate days): once with gels and once without. The swimmers' times slowed down significantly more over the course of the workout when they received only water than when they received the gels. Every timed 100-yard sprint from the 4th interval to the 24th interval was significantly faster for the carbohydrate-protein gel compared to the water. Swimmers maintained their times through 21 intervals while ingesting the carbohydrate-protein gel; only the 24th interval was slower than baseline. While ingesting water, however, swimmers slowed significantly by the 4th sprint in the first set and they continued slowing through the 24 intervals. On average, their time for the final 100-yard sprint was two seconds faster in the carbohydrate-protein gel-fueled workout than in the other workout. Blood samples were taken from the swimmers and analyzed for the concentration of creatine kinase (CK), a marker of muscle damage, before training and 24 hours after training, to determine how much muscle damage occurred during the workout. Swimmers experienced 25 % less muscle damage during the Accel Gel workout.
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This study demonstrated that "supplementation of a (carbohydrate-protein gel [Accel Gel]) provided significant improvements in cycling time to exhaustion compared to a (carbohydrate-only gel [GU Energy Gel])." It also demonstrated that "post-exercise CPK (a biomarker of muscle damage) was not significantly elevated following the carbohydrate-protein gel trial, while it was significantly elevated following the carbohydrate-only gel trial." Thirteen recreationally competitive male (8) and female (5) cyclists completed a stationary bike ride to exhaustion while consuming either the carbohydrate-only gel with water or the carbohydrate-protein gel with water in double-blinded fashion. After each ride blood samples were taken and analyzed for CPK. Subjects performed 13 % longer in the carbohydrate-protein gel trial than in the carbohydrate-only gel trial. CPK levels were significantly elevated after the carbohydrate-only gel trial, but not after the carbohydrate-protein gel trial. Responses between treatments were similar for both males and females.
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This study found that "Using Accel Gels in conjunction with a hydration pack can reduce training impulse of alpine skiers." Fifteen alpine ski racers/coaches completed a study to address training effort when daily water consumption was controlled (1.5 L/session) using a CamelBak. Over a four-day period, on two consecutive days, subjects received carbohydrate-protein energy gels (Accel Gel) throughout a four- to five-hour training session. On the other two days they received only water. Perceived effort was significantly lower on the days when skiers received Accel Gels, although they skied the same vertical distance during both trials. Training impulse equals perceived efforts x vertical distance skied. Therefore training impulse was lower in the Accel Gel trial.
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This study involving slalom ski racers demonstrated that "consuming a (carbohydrate-protein gel [Accel Gel]) and water increased training run finish success, increased the number of gates trained per session, and resulted in a lower rating of perceived exertion over a group that drank only water." Thirty ski racers, 14 to 19 years old, were matched by gender, age, and slalom points. During a two-hour slalom training session, one of the pair ingested a carbohydrate-protein energy gel with about 150 mL of water, while the matched skier ingested 150 mL of flavored water after each training run. Skiers using Accel Gel® and water missed only 13 % of their gates, while skiers using just water missed 34 % of their gates. Ratings of perceived exertion were 19 %lower on average in the gel group.
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This study showed that "[carbohydrate-protein] gels provide significant performance advantages over [carbohydrate-only] gels, as similarly demonstrated in studies using [carbohydrate-protein] beverages." Thirteen recreationally competitive cyclists completed two timed trials to exhaustion on stationary bikes. At 15-minute intervals throughout these rides, subjects received either a carbohydrate-only gel (Gu Energy Gel®) or a carbohydrate-protein gel (Accel Gel™), which were matched for carbohydrate content. Subjects rode 13 % longer when using the carbohydrate-protein gel.
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This study determined that "the rate of [post-exercise] recovery is coupled with the rate of muscle glycogen replenishment," and that "recovery supplements should be consumed to optimize muscle glycogen synthesis as well as fluid replacement." Eight endurance-trained cyclists performed two trials consisting of a two-hour glycogen depletion ride followed by an exhaustive ride at high intensity. Subjects received either a carbohydrate-protein beverage (Endurox R4) or a carbohydrate-only sports drink immediately and two hours post-exercise. Post-exercise ingestion of carbohydrate-protein beverage (Endurox R4), in comparison to the carbohydrate-only beverage, resulted in a 55 % greater time to exhaustion during a subsequent exercise bout at 85 % VO2max. Ingestion of the carbohydrate-protein beverage resulted in a 17 % greater plasma glucose response, a 92 % greater insulin response and a 128 % greater storage of muscle glycogen compared to the carbohydrate-only beverage.
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This study showed that "a [carbohydrate-protein] supplement is more effective for the rapid replenishment of muscle glycogen after exercise than a [carbohydrate-only] supplement of equal [carbohydrate] or caloric content." Subjects completed a very long workout on stationary bikes and then drank either a carbohydrate-protein sports drink (Endurox R4) or a carbohydrate-only sports drink of equal calories. Four hours later, muscle glycogen was significantly greater in those given the carbohydrate-protein sports drink.
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This study demonstrated that "a [carbohydrate-protein] drink following glycogen depleting exercise may facilitate a greater rate of muscle glycogen resynthesis than a carbohydrate-only beverage, hasten the recovery process, and improve exercise endurance during a second bout of exercise performed on the same day." Ten male athletes completed a long workout on stationary bikes, then drank either a carbohydrate-protein sports drink (Endurox R4) or a carbohydrate-only sports drink. After a two-hour rest the subjects completed an endurance bout to exhaustion. The athletes went 20 % longer with the carbohydrate-protein sports drink than with the carbohydrate-only sports drink.
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This study showed that "The greater rate of recovery following glycogen-depleting exercise during the [carbohydrate-protein] treatment shown [in previous studies] was likely due to a greater glycogen restoration." Eight endurance-trained cyclists performed two trials consisting of a two-hour glycogen depletion ride followed by ingestion of 12 ounces of a carbohydrate-protein supplement (Endurox R4) or a carbohydrate supplement immediately and two hours post-exercise. Trials were randomized and separated by seven days. Blood samples were collected prior to exercise and throughout the four-hour post-exercise recovery period. Muscle biopsies were taken immediately after and four hours post-exercise for determination of muscle glycogen content. Ingestion of the carbohydrate-protein supplement resulted in a 17 % greater plasma glucose response, a 92 % greater insulin response, and a 128 % greater storage of muscle glycogen compared to the carbohydrate-only supplement.
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This study found that "recovery from glycogen-depleting exercise was significantly enhanced by [Endurox R4] Recovery Drink when compared to Gatorade. In addition, [Endurox R4] Recovery Drink decreased the formation of final oxidation products, when compared to Gatorade." Eight male cyclists performed a two-hour cycling exercise bout followed by one to three five-minute sprints. A four-hour recovery period ensued in which the subjects were given 24 ounces of either Endurox R4 or Gatorade. A performance test to exhaustion was then conducted. The recovery phase showed significant increases in both plasma glucose and insulin following Endurox R4 ingestion as compared to Gatorade. There was an average 66 % increase in time to exhaustion during the performance ride following Endurox R4 ingestion compared to Gatorade. Final oxidation products following Endurox R4 ingestion were significantly decreased as compared to Gatorade ingestion.
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This study demonstrated that "a [carbohydrate-protein supplement], by providing additional [carbohydrate] and amino acids, may reduce post-exercise muscle stress, as evidenced by a 36 % decrease in 24-hour [creatine kinase] levels. Ten college-age males and females completed a 45-minute run, rested in a 10-minute transition, cycled for 90 minutes, and then performed a time trial (TT). During the transition and 30 minutes into the bike segment, subjects ingested either a 15 % carbohydrate-protein beverage (Endurox R4) or a carbohydrate-only beverage. Blood samples were collected and analyzed for creatine kinase (a biomarker of muscle damage), lactic acid and glucose. There was a 36 % reduction for the 24-hour post-exercise creatine kinase level in the carbohydrate-protein treatment.
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