Walking Before Eating Offsets Fatty Feasts
Even a Single Lengthy Stroll Helps Protect the Heart
Dec. 22, 2004 -- Lace up your walking shoes before hitting the holiday banquet table. Just one long walk can protect your heart from fatty foods, making it easier to eat, drink, and be merry with minimal guilt.
Recent studies show an association between fatty meals and an immediate decrease in blood vessel function. This dysfunction and inflammation are key to the development of atherosclerosis and heart disease, and more recent evidence has linked these findings to the effects of a fatty meal.
The researchers say that a single exercise session of moderate intensity can reduce these detrimental fats by as much as 20%- 25%.
But could prior exercise have an affect on what fat does to healthy vessels? That's what researchers from Scotland's University of Glasgow wanted to find out. They studied 20 obese and normal-weight men; all were healthy middle-aged nonsmokers.
The men walked on a treadmill for 90 minutes. That's a lot longer than typical recommendations calling for a half-hour of daily exercise for basic fitness.
No participants -- even the skinny ones -- were used to such lengthy workouts. But the pace was moderate, and everyone completed the session without much trouble. No one complained of undue tiredness or soreness.
The next day, participants got a break. They didn't exercise at all. Instead, they indulged in a high-fat meal.
Granted, the menu was pretty unusual. The fatty fare consisted of whipping cream, fruit, cereal, nuts, and chocolate. The nutritional tab: 80 grams of fat, 70 grams of carbohydrates, 12 grams of protein, and a whopping 1,030 calories.
Cuisine wasn't the point. Instead, the goal was to see if the long walk could lessen the effect a fatty meal has on blood vessel function.
For comparison, the men also ate the same meal without walking the day before. The two tests were held a week or two apart.
All that treadmill time paid off. After the fatty meal, levels of blood fats called triglycerides were 25% lower for the walkers.
Triglycerides are a form of fat used by the body for energy. They're found in foods and are essential in modest amounts. But excessive triglycerides raise the risk of heart disease and diabetes. That's one reason why Americans are advised to limit their fat intake to 30% of their daily calories, says the American Dietetic Association.
Imaging also showed that tiny blood vessels in the men's forearms were 25% more responsive after the walk. Compared with men who did not exercise, the blood vessels in men who participated in the exercise intervention were more capable of dilating, allowing for improved blood flow. A sign of healthy blood vessel function is its ability to dilate and expand.
That's another positive sign for safeguarding the heart. The fatty meal still made the blood vessels somewhat sluggish, but the setback was smaller with the pre-meal walk.
The findings indicate that even one exercise session can make a difference, say the researchers, who included Jason Gill, PhD, of Scotland's University of Glasgow.
No time for a 90-minute walk? Try two or three shorter sessions instead, says Gill, in a news release. New exercisers may want to check in with a health care provider first.