Lauren Goss IM 70.3 Ecuador winEndurance athletes often struggle with fueling strategies.  Balancing the consumption of calories, electrolytes and water can be difficult, and many athletes use a concoction of different products from different companies to try and maximize the consumption of carbohydrates, electrolytes and water. They may be doing everything right, but many times are still left with gastric distress, cramping or the dreaded bonk.

The issue is that our digestive systems do not work in silos—they must absorb calorie, electrolytes and water concurrently while an athlete is racing.   The simple act of adding a gel or electrolyte capsules to a fueling plan can be enough to throw the body’s osmolar balance off, which in turn slows gastric emptying and absorption of all nutrients.

A newly published study shows electrolyte consumption during exercise stimulates hydration and therefore enhances performance. EFS-PRO  was designed to maximize hydration through its exclusive ‘Optimal Absorption Technology’ which shuttles water, electrolytes and other essential nutrients through the digestive system more efficiently creating a positive influence on total hydration status.

‘Optimal Absorption Technology’ shuttles water, electrolytes and other essential nutrients through the digestive system more efficiently…

Optimal Hydration Technology

L-Alanyl L-Glutamine – unique to EFS-PRO, it’s been clinically proven to significantly improve absorption of water and electrolytes in humans under exercise stress and mild dehydration.  This special dipeptide amino acid is a highly-soluble, water-stable source of glutamine that has been shown to improve endurance performance through its positive influence on hydration.   One key mechanism of action is its ability to shuttle water and micronutrients through the digestive system thus eliminating cramping and GI distress.

In a study done in the Journal of the International Society of Sports Nutrition, L-Alanyl L-Glutamine and water were administered to college students with induced dehydration of -2.5% while a second group used only water. The group using L-Alanyl L-Glutamine showed a dramatic improvement in their hydration status as well as their serum sodium levels. This group also significantly improved their endurance performance in a treadmill exercise (2). 

Cyclic dextrin – a super low osmolality (150mOsm) carbohydrate source that has been clinically proven to have the fastest gastric emptying time of any carbohydrate. (4) This low-osmolality and superior gastric emptying time means athletes can be assured what they drink goes directly to working muscles.  This also meansEFS-PRO can be mixed at stronger concentrations and still be absorbed properly. In a published clinical study done on competitive swimmers, those using cyclic cluster dextrin significantly improved swimming time over swimmers using other carbohydrate sources. (3) 

Gastric emptying chart.

New Electrolyte Study

In a 2015 study in the Medicine and Science in Sports Journal, researchers investigated the effects of electrolyte supplementation on ½ Ironman performance.   Previous studies in both lab settings and field tests have reviewed the effectiveness of electrolyte supplementation with varied results. Lab studies control fluid intake and match with fluid losses making the correlation with electrolyte content and performance hard to confirm. In field studies, variables like fitness, experience and carbohydrate intake were not held constant (1). 

This study took place in a real life ½ Ironman race, allowing athletes to monitor their own fluid consumption.  The study matched subjects on fitness level, age and anthropometric data.  The most important alignment was done by matching previous best times in 70.3 race performance.   Both the control group and electrolyte supplementation group had previous bests of 301 minutes (5 hours) and had similar training loads of 8km swimming, 180km cycling and 35km running each week.  This allowed researchers to see what the performance differences might be following the race.   

The study by Del Cosso, et al. used two groups of 13 subjects where both groups were similar in age, fitness level, amount of training and best race performance.    The control group was given 12 capsules to be used at specific times throughout the race and did not know they contained only cellulose.  The test group was also blindly given 12 capsules that were filled with 2580mg sodium, 3979mg chloride, 756mg potassium and 132mg magnesium. Athletes then consumed their regular fueling plan during the race including drinks that contained additional electrolytes. 

  Study 5 servings EFS-PRO
Sodium 2580mg 2500mg
Chloride 3979mg 2650mg
Potassium 765mg 1,100mg
Magnesium 132mg 250mg
Calcium * 500mg

*The study made no claims on the consumption of calcium.

Results of the study showed that the group consuming the electrolyte capsules completed the ½ Ironman at an average race time of 307 minutes (5 hours – 7 min).  The control group took 333 minutes (5 hours – 33 min), making the electrolyte group 26 minutes (8%) faster than the control group. 

It’s important to note that muscle contraction strength, blood osmolality, serum electrolyte concentrations and carbohydrate intake did not significantly vary between the two groups. The electrolyte group did, however, ingest 400ml (13.5oz) more fluid than the control group even though both groups were asked to simply fuel/drink as they saw fit.   

The researchers theorize that the ingestion of electrolytes may create a change in osmotic stimulus that further creates thirst. This may be why the electrolyte group ingested 13.5oz more fluid than the control group in this study.


EFS-PRO is a technologically advanced drink designed to push the absorption of electrolytes, fuel and water through the digestive system.  Through its low osmolality, high electrolyte system, aided by L-Alanyl L-Glutamine,EFS-PRO ensures everything you drink goes directly to the working muscles and avoid cramping and GI distress. 


J. Del Cosso et. al.; Effects of oral salt supplementation on physical performance during a half-ironman: A randomized controlled trial.  Medicine & Science in Sports. 2015.

Hoffman JR, et al. Examination of the efficacy of acute L-Alanyl L-Glutamine ingestion during hydration stress in endurance exercise. Journal of the International Society of Sports Nutrition. 7:8, 2010

Int J of Sports Med, 26: 314-319, 2005
Biosci Biotechnol Biochem, 63: 2045-2052 , 1999

Takii, H; Fluids containing a highly branched cyclic dextrin influence Gastric Emptying rate.  Int Journal of Sports Medicine; 2005; 26: 314-319.