Now that the days are getting shorter and the unrelenting heat of summer fades into the cool cocoon of fall, many people will shift into regular autumnal patterns, returning to school and work schedules.
Exercise is one of the things that may have been changed, reduced or MIA during the summer months for regular fitness buffs. But for people starting on a new journey of exercise, it can be an exciting, but somewhat daunting task to begin a new routine.
When starting an exercise routine, knowing what to do is only half the battle. Staying consistent and motivated is very important, and part of that process is understanding which sensations are good and which are bad during exercise.
In my experience, people often will experience discomfort during the first 10 to 15 minutes of exercise and this will dissuade them from continuing. But if they understood better what is happening in their muscles and how to modify the activity, they would have a much more rewarding experience. Some people have called the feeling of overcoming this initial distress getting their ‘second wind.’
When you begin to exercise, many different processes occur, but they take time to kick in. Nerves send messages to the muscles quickly, but hormones must be released, heart rate must increase and capillaries must dilate to increase blood flow, and so on.
Here is a breakdown of what goes on.
During the first few minutes of exercise, the muscles can’t make use of the abundant fat in the body because there isn’t enough oxygen around to burn it yet.
It can take anywhere from a few minutes (in the case of an elite athlete) to about 10-15 minutes (in the case of a sedentary person) for enough oxygen to arrive at the muscles to burn a significant amount of fat for energy – called aerobic metabolism.
Until that time, carbohydrates are burned in the absence of sufficient oxygen (called anaerobic metabolism).
When carbohydrates are burned in this fashion, the waste product is lactic acid, which accumulates quickly in the muscle and causes a burning sensation.
A well-conditioned individual can circulate lactate to the heart, liver and muscles quickly to use it to produce more energy, but in a poorly conditioned individual, this process is slower and lactate builds up in the muscle and causes fatigue and discomfort.
This burning is unpleasant and can be accompanied by some breathlessness, and it is the main reason so many people associate negative feelings with exercise.
In order to burn carbohydrates, they need to be brought out of storage from the liver and dumped into the blood stream.
To accomplish this feat, the hormone Glucagon is secreted from the pancreas. We also store glucose in our muscles (called muscle glycogen), but a poorly trained person does not store much glycogen, which also inhibits performance.
Adrenal hormones and Glucagon also take time to be released and travel to fat storage areas in the body to release fat into the blood stream for use by the muscles. Heart rate is stimulated to increase by many hormonal and neural factors, including increased blood levels of carbon dioxide, hydrogen ions, epinephrine, blood pressure changes, breathing rate increases and mental input.
It can take two to three minutes for the heart rate to increase and stabilize after you begin exercising. It also takes time for arterioles and capillaries to dilate in your muscles to get more blood and oxygen to the muscles.
So if you are starting a new exercise routine, go easy on yourself and understand that if you are not in great shape that all these systems – take time to kick into gear and that a little discomfort can be normal before you get your second wind. If you need to, just ease your pace a little for the first 10 minutes and warm up into your activity well.
Once you get in better shape, you will tolerate this period better and all your regulation systems will improve, too, allowing you in time to go a little faster and longer with less discomfort.
Kerry Senchyna holds a bachelor of science degree in kinesiology and is owner of West Coast Kinesiology
in Maple Ridge.