Types of Stress
Life can bring on many types of stresses – physical, psychological, sleep deprivation, environmental, and the list could go on. Our body has different mechanisms to respond to overall stress, no matter where it is coming from.
When is comes to physical stress, exercise is the biggest culprit. Even a fast-paced walk can trigger a stress response from the body. What happens when you add more stress such as resistance bands, load from weights, and increased sets and reps?
To start, we have to understand how our body operates at rest (aka homeostasis). Keep in mind that our body will always fight to get back to homeostasis. In a hemostatic state, blood glucose levels stay constant because it is being taken up and produced by all tissues equally.
Exercise adds stress to our body. As a response to this stress, there are many changes that take place within the body. The three major components of the response include CNS expenditure, blood glucose levels and hormone levels.
There is a rapid increase in energy demands and the sympathetic central nervous system (CNS) works harder when we exercise. The increased work of the CNS results in the breakdown of glycogen stores. The breakdown helps give immediate energy and maintain blood glucose levels (tries to get back to homeostasis). Fatigue during high intensity exercise means the body is cueing that glycogen and blood glucose stores have been depleted. During long training sessions at moderate intensity, the body utilizes fatty acids and triglycerides for continued energy.
Blood flow is also affected during exercise. Blood flow increases to the muscles and there is an increase in the uptake of glucose to the muscles. The body has to work a little harder to produce enough glucose during this time in order to maintain blood glucose levels. Hence the glycogen breakdown mentioned earlier.
Three hormones are directly involved in stress response – epinephrine, norepinephrine and cortisol
Epinephrine – Have you ever tested your one rep max or prepared for a new PR and found that your heart begins to race or a sudden rush of energy washes over you? That is epinephrine, better known as adrenaline, preparing you for this stressful situation. This flight or flight hormone can last up to an hour after your intense training session.
Norepinephrine – Similar to epinephrine, it increased arousal during stressful moments. It will make you more focused and more responsive. During exercise, it will constrict the blood vessels in areas that are not involved in the exercise to help increase blood flow to areas that are used.
Cortisol – This stress hormone helps to maintain fluid balance, blood pressure and regulates more complex body functions such as fat metabolism. Cortisol is released if the body is under too much physical stress or it has not properly recovered from a previous workout. The body will break down muscle protein for fuel instead of conserving it to repair damaged tissues if cortisol levels are increased for too long.
Fight for Homeostasis
Stress is inevitable and luckily, our bodies are equipped for it. However, too much stress can truly throw off the rhythm and function of the body. During off-season training, when stress in the weight room tends to increase, be mindful of how the body is responding to the stress. Proper nutrition and recovery is necessary to get back to homeostasis.