Food, Exercise, and Your Metabolism

Written by: Krista Reader

That’s right, another article on the importance of exercise. As your medical partners, we want to consistently remind you how important regular, purposeful movement can be. One of the most frequent questions we get from clients is, “Why can I no longer lose weight like I used to?” or “Why am I slowly gaining weight as I get older?” While the answer is not always simple, most of the time we will start with a discussion about what you are eating, how you are exercising, and what happens to our metabolism as we get older.

Let’s start with a quick refresher on what your metabolism actually is. Most of us think of metabolism as the rate at which we burn calories. That is true, but it is also the body’s ability to breakdown the foods we eat. It’s the body’s ability to burn the various nutrients from the food we eat to help us maintain a healthy body. The healthier the food, the more nutrients our body can burn, and conversely, if we eat unhealthy foods, less fuel opportunity for our body to burn.

Understanding the importance of what we eat (our fuel content), we also need to understand what is happening to our metabolism as we age. The aging process starts at a cellular level and with normal aging comes a slowing in the ability for our cells to repair themselves, mostly due to damage from free radicals. This may slow the weight loss process down. More importantly, once over the age of 30 we begin to slowly lose muscle mass. As muscle burns more calories (energy) and increases your overall basal metabolic rate (the number of calories your body burns just to function), this means that your energy burn is decreasing, and it will take you longer to burn off what you eat. Ultimately, you will burn fat less efficiently.

Yes, this is a frustrating and inevitable result of aging for most of us. But there is a way to change this cycle. We know that we are what we eat. Diet can account for up to 80% of weight gain and body composition. Eat real food, eat often, drink lots of water.

Next in line is exercise. When we exercise, we burn fat, we increase our metabolic burn rate AND we have the ability to increase muscle mass. Muscles burn more calories than fat.

When we coach our clients on not only the benefits of exercise, we also know that integral to changing your fitness is to address the type of exercise you need to do. Starting with a brisk walk, or a swim is a great start, but if you truly want to change your metabolism, burn more calories, you have to also focus on the type of exercise you are doing.

The best exercise program is one that is a combination (and changing rotation) of aerobic exercise, interval training, and strength training. We do believe that any exercise is important, but let us tell you a bit more about why each of these options are so important.

Aerobic exercise

When you participate consistently in a form of aerobic exercise (running, biking, swimming, spinning, elliptical, fitness classes, etc) your heart gets stronger and pumps more blood with each beat. Elite athletes, for example, can have significantly larger left ventricles than average individuals. Conditioned hearts have greater diameter and mass (the heart’s a muscle too and gets bigger when you train it). When your heart holds a greater volume that means it doesn’t have to pump as fast to meet the demands of exercise or daily life (lower resting heart rate). Fewer beats and more volume mean greater efficiency. Athletes can have a resting heart rate as low as 40 beats per minute; the average is 60-80. Which heart do you think will get tired earlier in life?

Downstream from the heart are your muscles, which get more efficient at utilizing oxygen when you do regular aerobic exercise. This happens because of an increase in the activity and number of enzymes that transport oxygen out of the bloodstream and into the muscle. This process is what builds your endurance. You will have more endurance because your muscles are not going to run out of oxygen as quickly. Measuring your V02Max is an excellent way to understand your current oxygen utilization capacity.

Interval training

Interval training has been used by athletes for years to build fitness. Interval training combines short, high intensity bursts of speed, with slow, recovery phases, repeated during one exercise session. Interval training works both the aerobic and the anaerobic system. During the high intensity part of your workout your anaerobic system uses the energy stored in your muscles (glycogen) to support the short bursts of activity. Your anaerobic metabolism works without oxygen and produces a by-product of lactic acid. As lactic acid builds, you will have a shortage of oxygen to the muscle, and it is during the slower, recovery phase that the heart and lungs work together to put this oxygen back and break down the lactic acid. It is in this phase that the aerobic system is using oxygen to convert stored carbohydrates into energy, i.e. burning calories!

According to the American College of Sports Medicine, more calories are burned in short, high intensity exercise. If you are counting calories burned, high intensity exercise such as intervals are better than long, slow endurance exercise, but be careful. There are risks inherent to high intensity training. This type of training can put a maximum load on your cardiovascular system (your heart and lungs), so it is imperative that you ensure you are physically ready for this type of activity. Talk to your primary care physician, educate yourself on interval training program, warm up, and listen to your body as you progress. We highly recommend investing in a heart rate monitor to help you create and maximize an interval training program’s results. Also, it is very important to allow your body appropriate recovery from interval training to avoid injury.

Strength training

As muscle mass diminishes with age, the only way to preserve or build it is to commit to a strength training program. In addition to helping you lose weight, strength training will help you develop strong bones, reduce risk of injury, build stamina, manage chronic conditions, sleep better and maintain focus.

Strength training is all about creating resistance for your muscles. Resistance training works by causing microscopic damage or tears to the muscle cells, which in turn are quickly repaired by the body to help the muscles regenerate and grow stronger. The breakdown of the muscle fiber is called “catabolism,” and the repair and re-growth of the muscle tissue is called “anabolism.” Anabolic means to grow, and that’s exactly what happens after you break down the muscle fibers with resistance exercise. To help your muscles re-grow, testosterone, insulin-like growth factor, growth hormone, protein, and other nutrients rush to the muscle after a resistance-exercise session to help repair the muscles to make them stronger. Your muscles will even heal and grow when you aren’t working out, and that is why it is so necessary to leave time between workouts for recovery.

There are several options to consider as part of your strength training program including:

• Body weight. You can do many exercises with little or no equipment. Try push-ups, pull-ups, abdominal crunches and leg squats.
• Resistance tubing. Inexpensive, lightweight tubing that provides resistance when stretched. You can choose from many types of resistance tubes in nearly any sporting goods store.
• Free weights. Barbells and dumbbells are classic strength training tools.
• Weight machines. Most fitness centers offer various resistance machines. You can also invest in weight machines for use at home.

Once again, be sure to check with your doctor before you start lifting weights if you have any medical conditions, injuries or illnesses. If you don’t know much about weighttraining, consider hiring a personal trainer, to help you set up your program. You should work all of your muscle groups each week so that you avoid muscle imbalances, which could lead to injury. Functional movement testing with a trained professional can help to prevent injury during resistance training and help you achieve your goals faster and more efficiently. If you would like more information on how to start, please contact our Healthfit 4 Life Fitness Team here.

Sounds like a lot of work?

There is no doubt that committing to an exercise program that encompasses aerobic, interval, and strength training can seem overwhelming and impossible to fit into your already busy life. The key to success here is to find a balanced program that you enjoy and fits into your lifestyle. After all, shouldn’t your health be a priority over everything else?

Aerobic and interval training sessions can be combined and / or alternated. Maybe you do 30 minutes on the elliptical 1-2 days a week at a steady heart rate and then another 1-2 of 20-30 minutes of interval. Balance that with 1-2 days of 40 minutes of strength training spending one day on your upper body, the other day on your core and legs. There are many, many options to ensure that you are aerobically and anaerobically conditioning your body. Educate yourself, create a plan, put it on the schedule and if you need some support, give us a call.

We often tell our clients that exercise should be scheduled into your day just like any other appointment. You wouldn’t miss that important meeting with a new client right? Make your workout session your new, most important meeting of the day. Commit to it, practice it, and then you will never want to give it up!