Carb Absorption & Utilization During Exercise
𝘞𝘩𝘺 𝘥𝘰 𝘴𝘱𝘰𝘳𝘵𝘴 𝘯𝘶𝘵𝘳𝘪𝘵𝘪𝘰𝘯 𝘱𝘳𝘰𝘥𝘶𝘤𝘵𝘴 𝘰𝘧𝘵𝘦𝘯 𝘤𝘰𝘯𝘵𝘢𝘪𝘯 𝘢 𝘷𝘢𝘳𝘪𝘦𝘵𝘺 𝘰𝘧 𝘥𝘪𝘧𝘧𝘦𝘳𝘦𝘯𝘵 𝘴𝘶𝘨𝘢𝘳𝘴?
The quick answer: To promote the largest & quickest delivery of carbs to your working muscles 💪🏼 !
All of the carbs you eat are made up of the monosaccharides: 𝙜𝙡𝙪𝙘𝙤𝙨𝙚, 𝙛𝙧𝙪𝙘𝙩𝙤𝙨𝙚 𝙖𝙣𝙙 𝙜𝙖𝙡𝙖𝙘𝙩𝙤𝙨𝙚. These are the simplest form of carbs and the form that our body can absorb. Disaccharides, which are also simple sugars, are just 2 monosaccharides linked together. Complex carbs are chains of glucose linked together (no fructose)
Once eaten enzymes break carbs down into monosaccharides and they enter the small intestine. In the small intestine there are 2 transporters that move them into the bloodstream.
The 1st is called 𝗦𝗚𝗟𝗧-𝟭 and it transports 𝗴𝗹𝘂𝗰𝗼𝘀𝗲 & 𝗴𝗮𝗹𝗮𝗰𝘁𝗼𝘀𝗲. This transporter can absorb a maximum of 𝟲𝟬𝗴 per hour. The second transporter is 𝗚𝗟𝗨𝗧-𝟱 and it absorbs 𝗳𝗿𝘂𝗰𝘁𝗼𝘀𝗲, but can only take in 𝟯𝟬𝗴 per hour.
By using a combination of sugars, manufacturers are able to get the right ratio of glucose + fructose to achieve an absorption rate of 𝟵𝟬𝗴/𝗵 compared to only 60g or 30g if glucose or fructose were used alone! (Note: no galactose is used since that’s found in milk and could cause gut issues). This high amount is not always necessary, such as for events lasting less than 2 hours. It won’t hurt to use a combination of carbs in those events, but the total needed will be less than 90g/h.