Morning workout could be unhealthy
By Bryant Stamford
Gannett News Service
Many of us find exercising first thing in the morning most convenient. We get it out of the way and don't have to worry about stealing time later in a busy day.
It sets the tone for the day, helping us get off to a relaxing start. And it's an efficient use of time, because we are going to shower, wash our hair, etc. anyway, so why not exercise first.
When you awaken from a night's sleep, your blood glucose (sugar-carb) level is likely to be a bit low, as are your stores of sugar in the muscles and liver.
This is not a problem if your morning exercise entails nothing more intense than a brisk walk. But it can be a problem for folks who spring into athletics right out of bed.
At rest, your fuel mix is about 65 percent to 70 percent fat, with the rest carbs. But when you start to exercise, the fuel mix shifts toward carbs. As the intensity of exercise increases, the dependence on carbs increases, reaching the point where the fuel mix is 100 percent carbs during maximal exercise.
There is a misunderstanding about fuel mix that is unfortunately perpetuated by naive exercise "experts." Logic might suggest that mornings, when your carb supply is running low and your stomach is empty, would be a good time to exercise because your body will be forced to use more fat as fuel. Wrong.
As exercise intensity increases and there is a greater dependence on carbs, using fat is not an option. So if carb supplies are low and fat cannot be used, your body will be forced to go after protein as fuel. The proteins in muscle are broken down into amino acids, and some of these are taken to the liver and converted to glucose (sugar) that is then substituted for carbs in the fuel mix.
To avoid metabolizing muscle during intense morning workouts, eat some light, fast-digesting carbs first to bring your blood sugar level up. Juices, power bars or a piece of whole-grain toast lathered with jam are good choices.
This will not only help preserve your muscle mass, it also will prevent you from wilting from fatigue during your workout.
The prevalence of heart attacks and strokes (caused by blood clots) is quite high in the first hours of the morning compared with other times of the day. Several factors may contribute.
Upon first awakening, there is a tendency for the arteries to be slightly narrower than later in the day. For the average person, this is not a big deal. But for someone who already has narrowed arteries caused by accumulation of cholesterol (atherosclerosis), further narrowing could be dangerous.
In addition, the blood is more likely to form clots, because in the early hours the platelets (blood cells responsible for initiating clotting) are "stickier" and more prone to congregate.
Clots can lodge in narrowed sections of the arteries, blocking blood flow to areas downstream. Without blood flow, there is no oxygen, and the result is death to heart tissue or heart attack (myocardial infarction).
The situation is worse in cold weather, because the blood vessels constrict to conserve body heat. Constriction of the vessels increases blood pressure, adding a third nasty factor to the mix.
The worst-case scenario would be getting out of bed and immediately moving outside on a cold day to engage in vigorous exercise, such as shoveling snow. So it's best for everyone — especially those at risk for heart disease — to ease into the day.
There's another reason why intense morning exercise can be problematic. You might awaken with stiffness in the lower back, and easing into the day with a mild walk is probably the best course of action.
When you are lying in bed, the body doesn't have to fight gravity. The discs between the vertebrae are relieved of pressure and swell. This causes ligaments between vertebrae to stretch.
Upon standing and encountering gravity, the stretched ligaments cause stiffness and discomfort. The natural tendency is to stretch. This is a bad choice, because it can aggravate the already stretched ligaments.
Jogging and other jarring, intense exercises also can be a problem, because the swollen discs will take more of a pounding than if they weren't swollen.
Taking a comfortable walk is recommended, because the gentle massaging action on the discs will reduce the swelling and take pressure off the ligaments. Eventually you can shift gears and increase the intensity of exercise.
Exercising first thing in the morning can serve you well if you understand the dynamics.
Fuel your body with easily digested carbs and ease into exercise slowly. If you are at increased risk for heart disease or stroke, morning exercise may not be a good choice.
Have a physical checkup and discuss with your doctor the options that are best for you.
