Effects of feeding meals with various soluble-carbohydrate content on muscle glycogen synthesis after exercise in horses.

The study investigates the effects of diets with varying soluble-carbohydrate contents on the rate of muscle glycogen synthesis after exercise in horses. The researchers found out that a high carbohydrate diet significantly quickens the replenishment of muscle glycogen content after strenuous exercise in comparison to low and mixed carbohydrate diets.

Methodology

• The research used seven fit horses for a three-way crossover study aiming to compare the impact of three different diets on their muscle glycogen synthesis following exercise.
• These diets were a High soluble Carbohydrate (HC) diet, a Low soluble Carbohydrate (LC) diet, and a Mixed soluble Carbohydrate (MC) diet.
• A glycogen-depleting exercise session is conducted on the horses, which was followed by feeding them with one of the three diets at intervals of eight hours for a total duration of 72 hours.

Results

• The study found out that feeding the HC diet resulted in a significantly higher glycemic response, lasting up to 72 hours, and an increased muscle glycogen concentration 48 and 72 hours after exercise.
• This was in contrast to the outcomes following the intakes of the MC and LC diets of the horses.
• In horses fed with the HC diet, muscle glycogen levels almost leveled up with baseline concentrations 72 hours after the exercise.
• The glycogen synthesis rate was also noticeably higher when horses were fed with the HC diet compared to when they were on the MC and LC diets.
• Glycogen synthase activity, an enzyme instrumental in converting glucose to glycogen, was discovered to be inversely related to the glycogen content.
• Protein content of glucose transporter-4, which is responsible for controlling glucose levels by mediating glucose transport across cell membranes, was lowest 72 hours after exercise when horses were fed the HC diet.

Conclusions

• The research concluded that muscle glycogen synthesis in horses is slower after glycogen-depleting exercise compared to human beings.
• However, it was also noted that feeding High Carbohydrate meals after strenuous exercise helped in speeding up the replenishment of muscle glycogen content by increasing the availability of blood glucose to skeletal muscles.
• This result was contrasted with the outcomes from feeding Low and Mixed Carbohydrate diets.