Sports Drinks Science

Sports Drinks Science

Read up on the science behind sports drinks, rehydration, electrolytes and how to easily make your own natural Sports Drink with our Liquidfuel Sports Gels!

Read up on the science behind sports drinks, rehydration, electrolytes and how to easily make your own natural Sports Drink with our Liquidfuel Sports Gels!

Sports Drinks:

During exercise fluid is lost due to increased sweat rates. Fluid losses greater than 2% body mass can result in increased perceived exertion (exercise feels harder), decreased thermoregulation (the body’s ability to cool itself), impaired blood flow to the muscles, and reduced cardiac output which results in increased heart rate. These effects may negatively impact exercise performance 1,2. If exercise sessions are longer than 60 minutes in duration, and performed in high ambient temperatures then there is more likely to be an effect on performance 3.

To reduce the negative effects to health and exercise performance, individuals are advised to hydrate at an equivalent rate to sweat losses. However, individuals often drink much less than they sweat, often only replacing about two-thirds of fluid losses, and in competition even less. This fluid restriction can be unintentional as the amount of fluid consumed can be limited by the availability of fluid and the rules of the game/match/competition 2. In addition to this, there is evidence that some athletes may start training or competition in a dehydrated state 2,3.

How quickly fluid and electrolyte balance is restored depends on how quickly fluid is emptied from the stomach and absorbed from the small intestine into the blood 3. This is affected by how much fluid is ingested (volume), the composition of the fluid (carbohydrate, electrolytes, etc.), and exercise intensity 2. Fluid volume strongly influences gastric emptying from the stomach, but this is affected by the concentration of carbohydrate in the fluid 2.

Sports drinks are used during exercise and contain carbohydrates (CHO) and electrolytes. Water absorption from a sports drink is influenced by the drink’s CHO concentration, CHO type (e.g. glucose, fructose, galactose, etc.), if there are single or multiple transportable CHO, and the levels of sodium and potassium (osmolality) 3.

Water follows the active absorption of dissolved solutes (CHO and electrolytes) 2. The absorption of CHO relies on special transporters in the intestinal wall, which is why drinks containing multiple CHO increases water absorption, and maintains glucose levels for exercise 3, as there are multiple transport proteins in the intestine. However, the concentration of carbohydrates in a solution will affect the gastric emptying of a fluid. If a drink is above 8% carbohydrates then fluid absorption is slowed. A carbohydrate concentration of 4 – 8% allows the maintenance of hydration status if consumed in 400 – 600 mL of fluid 3.

 

Hypotonic vs Isotonic vs Hypertonic:

This variation in carbohydrate (and electrolyte) content in sports drink makes drinks either hypotonic, isotonic, or hypertonic. Tonicity refers to the concentration of solutes in fluid compared to the concentration of solutes in human body fluids. In sports drink, the solutes are carbohydrate and electrolytes and will determine if it is more suitable for hydration or as fuel source during exercise.

Hypotonic sports drinks have been found to be better for hydration than either isotonic or hypertonic drinks, and even more effective than plain water 1. Drinks with higher carbohydrate content (hypertonic) provide more energy which is useful for longer exercise durations as they provide more glucose to maintain exercise performance. *Isotonic drink solutions have been found to negatively affect hydration status, particularly during exercise conditions 1.

 

Why Mānuka Honey?

Mānuka Honey is primarily carbohydrates (~ 80%), mostly glucose (~ 30 – 35%) and fructose (~ 35 – 40%). Mānuka Honey also contains vitamins, minerals, and antioxidants. The glucose and fructose provide energy to working muscles during prolonged activity, and activity interspersed with high intensity efforts. Glucose is absorbed faster, while fructose is absorbed slower. This means a more sustained supply of energy to the working muscles. Research shows exercise performance improvements for glucose-fructose solutions if the exercise is over 2 hours in duration, and in intermittent type activities. The electrolytes in our gels help with the absorption of the carbohydrate.

 

Make your own Sports Drink - The Scientific Way

Hypotonic:

  • Add one LiquidFuel to 600 mL water.
  • Concentration - 4.2%
  • Best for hydration, and re-hydration

Hypertonic:

  • Add two LiquidFuel to 600 mL water.
  • Concentration – 8.4%
  • Best for providing glucose and long sessions where extra energy is required.

 Check out our Liquidfuel here.

Author Credit: Lillian Morton - CHIEF SCIENCE OFFICER

  • PhD Medical and Health Sciences. MSc (dis).
  • IOC Sports Nutrition Diploma.
  • ISAK Level 3.
  • NZ Registered Nutritionist.

Lillian comes from decades of working with High Performance Sports NZ, Olympics, Rugby New Zealand continues to specialize in working with high performance athletes. She is a researcher and scientist, developing research methodologies, keynote speaking and more.

 

 References:

  1. Rowlands DS, Kopetschny BH, Badenhorst CE. The hydrating effects of hypertonic, isotonic and hypotonic sports drinks and waters on central hydration during continuous exercise: a systematic meta-analysis and perspective. Sports Medicine. 2022 Feb 1:1-27.
  2. Shi X, Passe DH. Water and solute absorption from carbohydrate-electrolyte solutions in the human proximal small intestine: a review and statistical analysis. International journal of sport nutrition and exercise metabolism. 2010 Oct 1;20(5):427-42.
  3. ACSM Position Stand. Stand P. Exercise and fluid replacement. Med. Sci. Sports Exerc. 1996;28.

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