Benefits
Faster gastric emptying than maltodextrin
HBCD's low osmolality and high molecular weight allow it to clear the stomach more quickly than equivalent doses of maltodextrin or glucose-based carbohydrates. This may help reduce the bloating, cramping, and reflux that endurance athletes commonly experience with concentrated carbohydrate drinks during long sessions.
Sustained energy without insulin spikes
Cluster Dextrin® supports a steadier, more gradual rise in blood glucose compared with simple sugars, which may help maintain energy availability across prolonged exercise. Endurance athletes have used HBCD-based drinks as an alternative to sucrose or maltodextrin blends to reduce reactive hypoglycemia after early-session carbohydrate intake.
Lower perceived exertion in endurance work
Cyclists and triathletes have reported lower ratings of perceived exertion (RPE) when consuming HBCD during prolonged exercise compared with control carbohydrates. The combination of stable energy delivery and reduced gut discomfort may help athletes hold higher relative intensities later in long sessions.
Improved fluid delivery during exercise
Because gastric emptying is the rate-limiting step in fluid absorption during exercise, HBCD's faster transit through the stomach may support better hydration in athletes consuming carbohydrate drinks. This makes Cluster Dextrin® useful as the carbohydrate base in hypotonic or isotonic intra-workout formulas.
Tolerated during high-intensity combat sports
Boxing, MMA, and other combat-sport athletes often struggle to consume conventional carbohydrate drinks before competition due to nausea. HBCD-based pre-event nutrition has been used in this population to deliver carbohydrate energy without the GI symptoms typical of maltodextrin or glucose drinks.
Mechanism of action
Low osmolality enables rapid gastric emptying
HBCD's narrow molecular weight distribution around ~160 kDa yields very low osmolality (<10 mOsm) compared with maltodextrin or glucose. Because gastric emptying rate is inversely related to osmolality, HBCD leaves the stomach faster, accelerating downstream small-intestinal absorption.
Branching enzyme cyclic glucan architecture
Produced by treating waxy maize starch with a branching enzyme, HBCD forms a highly branched cyclic structure with alpha-1,4 and alpha-1,6 linkages. This compact branched cluster resists rapid alpha-amylase cleavage at the surface while still being fully digestible, supporting a slower, steadier glucose release.
Stable glycemic and insulinemic response
Because HBCD is absorbed more progressively than maltodextrin, the postprandial glucose and insulin curves are flatter. This blunted insulin response may help spare muscle glycogen utilization and reduce post-ingestion rebound hypoglycemia during exercise.
Reduced gut osmotic load
Conventional sport-drink carbohydrates draw water into the intestinal lumen via osmotic gradients, contributing to bloating and diarrhea during exercise. HBCD's low osmolality minimizes this osmotic shift, which may explain the lower incidence of GI distress reported by athletes.
Clinical trials
Crossover trial comparing a beverage containing highly branched cyclic dextrin against maltodextrin during prolonged endurance exercise. Outcomes: rating of perceived exertion (RPE), blood glucose, lactate, and metabolic markers. Published in Bioscience, Biotechnology, and Biochemistry.
Trained endurance athletes; crossover design.
HBCD ingestion was associated with significantly lower increases in RPE at 30 and 60 minutes post-ingestion compared with maltodextrin. Blood glucose patterns were comparable between conditions but subjective effort was lower with HBCD, supporting the hypothesis that HBCD may help athletes maintain a given workload more comfortably.
Randomized trial in male athletes comparing a sports drink based on highly branched cyclic dextrin against a glucose-based drink during exhaustive endurance exercise. Outcomes included plasma cytokines and immunoendocrine markers. Published in Journal of Sports Medicine and Physical Fitness.
Male endurance athletes; exhaustive exercise protocol.
The HBCD beverage produced attenuated post-exercise inflammatory cytokine responses compared with the glucose-based drink, consistent with reduced exercise-induced immunoendocrine stress. Carbohydrate delivery and tolerance were comparable, supporting HBCD as an alternative carbohydrate source for endurance sessions.
Randomized double-blinded crossover trial examining the effects of intra-session HBCD supplementation on mechanical, metabolic, and perceptual responses during resistance exercise. Outcomes included repetitions completed, movement velocity, and perceived exertion. Published in Clinical Nutrition ESPEN.
Trained adults completing standardized resistance training protocol.
Intra-session HBCD intake produced modest, mixed effects on mechanical performance and movement velocity, with no consistent advantage over placebo for total repetitions, suggesting HBCD's ergogenic value is most evident in endurance and prolonged work rather than acute resistance training.