Adaptations to Exercise

During the first few weeks of an exercise program the body goes through many changes.  For the new endurance walker or runner, the 4-5 training sessions you do each week trigger a lot of positive changes both on the inside and on the outside. The body’s adaptations to exercise take time —doing too much too soon can damage your body rather than strengthening it.  It takes a consistent, and progressively more difficult, effort over an extended period to develop athletic performance. This is true for elite athletes and it is also true for beginners. Remember, everyone starts as a beginner. The number one priority for athletes of all abilities is to avoid injury so that training can continue and performance can improve. This means carefully balancing how much time is spent each week working out at low intensity, moderate intensity, vigorous intensity and no intensity (resting). This is not an art, it is science.  A long distance training schedule is based on that science. If followed, it works!

Following your training schedule will enable your body to keep up with the demands you are putting on it. This is why it is vitally important that you do not skip your 2-3 short weekday walks or once per week long distance walk (unless you are sick or injured that week.)  Over time, doing too little will damage your muscles and internal systems because you will be overworking them on the days when you exercise. Just because you can make your body exercise just once per week does not mean that it is good for your body to do so!  It is also important that you gradually increase the intensity and duration of your workouts by following your schedule. If you do too much too soon, your body will not be able to keep up with you. It needs time to adapt to the additional workload and it needs rest to repair damaged tissues prior to your next workout.  

PLEASE NOTE: There are no shortcuts to fitness. That means you cannot ramp up too fast to get there more quickly; nor can you skip workouts to get there more easily (with less effort). You have to do exactly what is needed! 

THE FIRST FEW WEEKS

The early stage (first 4-6 weeks) adaptations are not visible to the naked eye but they are happening even though you are not consciously aware of them. You may think that not much is going on and that it is taking a long time to see any real progress. You are making a huge amount of progress but it is happening on the inside so you are not aware of it. These internal changes must happen before the external changes will become apparent. The good news is that the changes on the inside are improving your health considerably. In a few weeks, your fitness level will have improved considerably as well!

• Week one—you will generally be feeling pretty good, energized and enthusiastic.
• Weeks 2 and 3—you will likely feel more tired and sore than week 1 and the perceived effort of exercise will be greater. This is because your body is doing a HUGE amount of work on the inside. You might start to doubt your ability during these couple of weeks and lose some of your enthusiasm. Do not give up! Everything that is happening is completely normal and indicates that your body is adapting as it should to the exercise.
• Weeks 4 to 6—you should start to feel less tired and sore and the perceived effort should start to decrease for the same level of exercise. When you get to this stage it means that your body has completed the first phase of chronic adaptation to endurance exercise. Congratulations – you are now an athlete!

You are now much healthier than when you started and are ready to begin increasing your fitness (which will continue to chronically adapt your body but at a slower pace so it won't exhaust you).

It is important to be aware that if you stop exercising now, all those fantastic and healthy changes that happened in your body will reverse so that in a few weeks you will be back to exactly where you started. 

WHAT IS HAPPENING TO MY BODY DURING EXERCISE?

During exercise your body experiences various acute responses (whether you are a new or an experienced exerciser). These acute responses include (but are not limited to), increased heart rate, sweating, energy consumption, muscle contraction and relaxation, and blood redistribution to active muscles. You can feel your body responding acutely to the exercise even if you cannot see exactly what it is doing. You feel your heart rate increasing and your temperature rising. You feel your muscles warming up, becoming more flexible and contracting and relaxing as you move. Within an hour or so of stopping exercise, you will notice that these acute responses cease and your body returns to its pre-workout state—which is good because this is what it is supposed to do.

What you are probably not aware of are the chronic adaptations to exercise that occur in the body of a new exerciser. Chronic adaptations are changes that happen to your body that will not return to their pre-workout state after you finish your workout. These changes are semi-permanent. This means that while you continue with an exercise program, the adaptations will stay. If you stop exercising altogether, within a few weeks your body will return to its pre-adaptation state. This is because your body makes changes to adapt to the activities that you perform. If you stop performing those activities, your body will reverse those changes because you no longer need them. This is the use it or lose it rule!

CHRONIC ADAPTATIONS TO ENDURANCE EXERCISE

In the first two weeks of training your blood volume will increase by 12-20%. This is due to an increase in blood plasma. This increase in blood volume reduces the viscosity (thickness) of your blood so that it can get to exercising muscles more quickly. This increase in blood volume means that your heart can become stronger and increase how much blood it pumps with each beat. The left ventricle of your heart will get stretched by the higher volume of blood and over time will increase in size. In addition, the walls of the left ventricle will become thicker and stronger. This means that more blood can enter the heart and the contraction that pumps the blood out to the body will be much stronger. 

Over the first few weeks of exercising, your resting heart rate will decrease by as much as 10-20 beats per minute (bpm). Your exercise heart rate will also decrease as much as 20 bpm or more. Your maximal heart rate will not change but you will be able to workout at a much higher intensity without your heart rate increasing as much. Your heart will be stronger reducing your risk of cardiovascular problems. 

Your muscles will also adapt. They will better utilize existing blood capillaries and create lots of new ones so that your muscles can extract more oxygen from the blood flowing through them. More oxygen extracted by the muscles means greater endurance in your muscles and more efficient use of your lungs (which are also strengthening). This means you will not get tired as quickly. 

Your body will become more effective at redistributing blood flow from inactive muscles and organs to active muscles during exercise so they work more efficiently thereby increasing endurance. This redistribution includes reducing the flow of blood to the digestive system during exercise (this is why you need to eat easily digestible foods before your long miles.)  

BENEFITS

In addition to knowing you are healthier and fitter and being proud of your new status as an athlete, there are other benefits to regular exercise. Your risk factor for many medical conditions and diseases is decreased significantly. These include, cardiovascular disease, hypertension, diabetes, high cholesterol, osteoporosis, Alzheimer’s. 

In addition to the decreased risk factors, you may also see improvements in existing conditions. People with borderline or moderately elevated blood pressure often experience blood pressure lowering to normal levels as a result of consistent exercise. Studies have shown that diabetics who consistently perform endurance exercise often require less insulin than before starting endurance training— a result of the body’s chronic adaptation to endurance exercise. Cholesterol levels can also be improved with regular exercise combined with a healthy diet.

The feel-good hormones in your body are also being stimulated much more often so you will feel happier and more energized the fitter you get. You will have better posture, better body composition (more lean body mass), and will feel (and look) more confident, poised and healthy. 

Keep training and you will continue to become stronger, healthier, fitter, and happier!

..........Coach Leenie