By Dr. Mercola
Exercise is important and crucial for weight loss, but not only because it helps you to burn calories.
About 80 percent of your ability to achieve an ideal body weight is related to your food choices, and new research shows that exercise may make it easier for you to make healthy food choices.
Exercise Boosts Your Will Power to Resist Unhealthy Food
One of your brain's many responsibilities, or "executive functions," is referred to as "inhibitory control."
This is what helps you to keep inappropriate or unhealthy behaviors under control, such as making you think twice before eating a gallon of ice cream for breakfast.
Since we are all inundated with temptations around the clock, this function is under constant strain.
Plus, it has only limited capacity and will grow fatigued with overuse, similar to your muscles. The end result is reduced will power to control impulsive behaviors, such as binging on junk food.
Exercise, it turns out, helps to enhance your brain's resources for executive functions like inhibitory control, making it easier for you to resist unhealthy food and instead choose healthy options that will further your weight loss goals. As researchers write in Obesity Reviews:
"These advanced cognitive processes are of limited capacity and undergo relentless strain in the current obesogenic environment. The increased demand on these neurocognitive resources as well as their overuse and/or impairment may facilitate impulses to over-eat, contributing to weight gain and obesity."
Exercise Enhances Your Brain's "Inhibitory Control" Making it Easier to Eat Healthy
Often regular exercise and a healthy diet go hand-in-hand, and this may not be a coincidence. Researchers have revealed that regular exercise enhances your brain's resources that facilitate inhibitory control, helping to compensate for the onslaught of temptations that encourage unhealthy eating (junk food advertisements, fast-food restaurants on every block, and so on).
Exercise also appears to make your brain more sensitive to signs that
you are full, offering a short-term benefit on top of the long-term,
behavior-oriented benefits noted above. As stated in Obesity Reviews:
"This impulsive eating drive may be counteracted by physical activity due to its enhancement of neurocognitive resources for executive functions and goal-oriented behaviour. By enhancing the resources that facilitate 'top-down' inhibitory control, increased physical activity may help compensate and suppress the hedonic drive to over-eat. Understanding how physical activity and eating behaviours interact on a neurocognitive level may help to maintain a healthy lifestyle in an obesogenic environment."
Exercise Even Alters Your Gut Hormones, Helping to Regulate Food Intake
Adding to the brain benefits, separate research presented at the 2011 meeting of the Society for the Study of Ingestive Behavior (SSIB) revealed another way that exercise may help control your body weight: by altering the hormones released by your gut after a meal.
In rats that exercised, increased levels of an inhibitory feeding hormone, amylin, were released when a meal was eaten, and a more rapid rebound of ghrelin occurred after the meal. Further, exercised rats treated with a gut hormone called CCK, which limits meal size, decreased their food intake more so than sedentary rats.
As one of the study's authors told Science Daily:
"Our new results indicate that the beneficial effects of exercise to control body weight might occur by altering the way in which meals release gut hormones that regulate food intake, and also by changing the sensitivity of individuals to these gut hormone signals."
Exercise is already known to increase sensitivity to leptin, the "satiety hormone" involved in appetite regulation, providing even more reason to make physical activity a regular part of your life. And as mentioned, there is far more to exercise and weight loss than simply burning calories! Not to mention, aside from the weight loss connection, exercise also offers profound benefits to your brain health, including helping to preserve your brain function as you age.
What's the Best Type of Exercise for Weight Loss?
One of the reasons why people continue to struggle with their weight despite engaging in regular exercise, aside from dietary mistakes, is because they're not doing the right kind of exercise! Several studies have confirmed that exercising in shorter bursts with rest periods in between burns more fat than exercising less intensely for longer periods. So, if you want to lose weight, cancel your hour-long treadmill session and replace it with 20-minute, high-intensity interval training like Peak Fitness instead!
An added bonus: you can cut the duration of your exercise session in half. Yes, one 2007 study showed you can burn more fat exercising for 20 minutes than for 40 minutes!
In their trial, women either exercised for 20 minutes, alternating 8 seconds of sprinting on a bike with 12 seconds of exercising lightly, or exercised at a regular pace for 40 minutes. After exercising three times a week for 15 weeks, those who did the 20-minute, alternating routine lost three times as much fat as the other women.
The researchers believe this type of exercise works because it produces a unique metabolic response. Intermittent sprinting produces high levels of chemical compounds called catecholamines, which allow more fat to be burned from under your skin and within your muscles. The resulting increase in fat oxidation is thought to drive the increased weight loss.
Further, high-intensity exercises like my Peak Fitness program engage a certain group of muscle fibers that you cannot engage through aerobic cardio, and engaging these muscle fibers causes a cascade of positive health benefits, including improved fat burning and also boosting your body's natural production of human growth hormone (HGH), which is a vital hormone that is key for physical strength, health and longevity.
For an in-depth explanation of the Peak Fitness program, which is a comprehensive exercise plan that also includes strength training, core exercises and stretching, please review this recent article.
Eating THIS May Sabotage Your Workout Efforts
Exercise may make it easier for you to eat healthy, but it's also important that you arm yourself with the knowledge of what's truly healthy and what is not. It's very easy to sabotage yourself with sugary foods and beverages, especially those that contain fructose, after a workout, and this includes so-called "healthy" beverages like "vitamin water," energy drinks, and similar types of sports and recovery drinks.
Fructose, which is hidden in virtually every processed food, tricks your body into gaining weight by fooling your metabolism, as it turns off your body's appetite-control system. Fructose does not appropriately stimulate insulin, which in turn does not suppress ghrelin (the "hunger hormone") and doesn't stimulate leptin (the "satiety hormone"), which together result in your eating more and developing insulin resistance.
Fructose also rapidly leads to weight gain and abdominal obesity ("beer belly"), decreased HDL, increased LDL, elevated triglycerides, elevated blood sugar, and high blood pressure -- i.e., classic metabolic syndrome. And, as HGH Magazine explains, consuming fructose, including that from fruit juices, within two hours of your workout will decimate your natural HGH production, so it should definitely be avoided for optimal benefits.
What Should You Eat After a Workout, and the Rest of the Time?
What you do eat after your workout is crucial to stop the catabolic process in your muscle and shift the recycling process toward repair and growth. If you fail to feed your muscle at the right time after exercise, the catabolic process will go too far and can potentially damage your muscle.
So ideally you should EAT within 30 minutes after your workout, and your meal should include fast-assimilating proteins, such as high-quality whey protein. Personally, I tailor my post-workout meals depending on the type of exercise I've done that day. As for what to eat the rest of the time, following the dietary advice available in my comprehensive nutrition plan is highly recommended. I am confident that if you adhere to the recommendations in this plan, you will be able to optimize your weight and your exercise results simultaneously.