Clinical Trial: Milk as a Recovery Beverage After Exercise for Improving Metabolic Health

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: The Effect of Milk as a Recovery Beverage After Exercise on Next-day Postprandial Triglycerides

Brief Summary: Fasting blood fat levels (triglycerides) are often used to assess risk of heart disease but the level of fats in the blood after a meal is actually a stronger risk factor. Most of our day is spent digesting the food we eat (which takes hours). Therefore, "after meal" blood fat levels have more of an impact on formation of blockages in our arteries and our risk of heart disease compared to "fasting" blood fat levels. Exercise performed hours before a meal reduces the level of fats that appear in the blood after a meal and can be used to reduce our risk of heart disease. Exercise has this effect because muscle burns fats for hours after an exercise session is over; this helps to remove fats from the blood. Unfortunately, when high-sugar drinks (such as Gatorade) are consumed after exercise, the possible benefits of exercise for reducing blood fat levels after meals is lessened. This is because high-sugar drinks stimulate the release of insulin into the blood. Insulin is a hormone which inhibits fat burning at the muscle. Previous research we did showed that foods that result in a slower rise in blood sugar and lower release of insulin preserve the beneficial effects of exercise for lowering blood fat levels after the next meal. Milk also results in a slow rise in blood sugar and low release of insulin; therefore, it may also have this beneficial effect if consumed as a recovery beverage after exercise. Our proposed research will test the effects of consuming two popular exercise-recovery drinks (Milk vs. Gatorade) on the rise in blood fat levels after a meal given hours later. A total of 20 obese or overweight participants will take part. We predict that milk consumed after an exercise session in the evening will result in a lower increase in insulin, a greater amount of fat-burning at muscle and a lower blood fat level after a meal given the next morning. Milk and Gatorade are both promoted as good beverages to promote recovery after exercise. Thi

Detailed Summary:

Cardiovascular disease is the leading cause of death in Canada with annual direct and indirect costs estimated at $22 billion. Fasting lipid levels are associated with elevated risk of cardiovascular disease; however, postprandial lipids - the level of TG after a meal, are very potent predictors of cardiovascular disease risk because most of an individual's day is spent in the postprandial state. This problem is especially evident in obese individuals, who have an elevated postprandial TG response. An acute session of exercise is beneficial for reducing postprandial TG; however, caloric consumption immediately after exercise can attenuate this beneficial effect.

Carbohydrate quality may influence postprandial lipid response. Carbohydrates can be classified by their glycemic index (GI), where high GI carbohydrates are rapidly digested and result in large elevations in blood glucose. Low GI carbohydrates are digested slowly and result in a smaller, more gradual rise in blood glucose. High GI carbohydrates are associated with an elevated risk of cardiovascular disease and increased weight gain; whereas low GI carbohydrates are associated with a reduced risk of cardiovascular disease and decreased weight gain. As mentioned above, one of the main benefits of an acute session of exercise is to reduce TG levels after a subsequent meal. For example, an evening exercise session reduces the blood TG response after a high-fat breakfast provided the next day. This effect is negated if high GI beverages (i.e. sugar-sweetened drinks) are consumed immediately after exercise. Sports drinks such as Gatorade, and skim milk or chocolate milk are the leading beverages promoted for consumption during recovery after exercise. Gatorade has a high GI (i.e. GI=89) due to the inclusion of high amounts of simple sugars, whereas milk has a low GI (i.e. GI=34). Milk may therefore be a healthier choic
Sponsor: University of Saskatchewan

Current Primary Outcome: Change in blood triglycerides [ Time Frame: Change from baseline to 6 hours ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Change in blood glucose [ Time Frame: Change from baseline to 6 hours ]
  Glucose levels after a high-fat breakfast
• Change in fat oxidation [ Time Frame: Change from baseline to 6 hours ]
  Fat oxidation after a high-fat breakfast
• Change in low density lipoproteins [ Time Frame: Change from baseline to 6 hours ]
  Low density lipoproteins after a high-fat breakfast
• Change in high density lipoproteins [ Time Frame: Change from baseline to 6 hours ]
  High density lipoproteins after a high fat breakfast
• Change in total cholesterol [ Time Frame: Change from baseline to 6 hours ]
  Total cholesterol after a high-fat breakfast
• Change in insulin level [ Time Frame: Change from baseline to 6 hours ]
  Insulin level after a high-fat breakfast
• Change in blood pressure [ Time Frame: Change from baseline to 16 hours ]
  Blood pressure after exercise and beverage consumption

Original Secondary Outcome: Same as current

Information By: University of Saskatchewan

Dates:
Date Received: May 12, 2017
Date Started: May 20, 2017
Date Completion: January 1, 2019
Last Updated: May 12, 2017
Last Verified: May 2017