This video has a lot of information regarding the differences between acute vs. chronic:
But to put it in a simpler way, I think of an acute response as one that is instantaneous. What immediately happens when you begin your work out routine. Your heart rate will go up. Same as your stroke volume (how much blood is pumped from one ventricle during each heart beat) and blood pressure. Body temperature will increase. If you’ve ever exercised, you’ve experiences all of this.
When dealing with a chronic response, you are dealing with what occurs over the long term, and the benefits received from working out. The muscular walls in the heart enlarge. Stroke volume has been increased, and so your heart won’t need to work near as fast and you won’t fatigue as easily as you would have in the acute response phase.
Increased respiratory capacity: CHRONIC (think long term. In the beginning, you are catching your breath and gasping for air when working at full capacity. As you keep working out, your body becomes adapted to the strains, and it builds a tolerance, and you’ll notice you can breathe easier. I noticed this the first time I ever ran on a treadmill, roughly a decade ago. I thought I would die! I could only do it for 5 minutes. Now, I run marathons, and can run for long distances at a time. It all begins with a small step, and the more you do, it easier it will get!)
Increased cardiac output: ACUTE. When you start out, the instant response will be more blood being pumped through the heart.
Improved body composition: CHRONIC. Over the long term, your body will begin to tone up, giving you lean muscle.
Decreased blood flow to visceral organs: ACUTE. So, here’s how I relate to this one. Some of you have heard of runner’s trots, correct? A terrible thing. I won’t go into detail, but if you want to read more about it, click here. So, when you work out, the blood starts to pump to the areas of your body it’s most needed. You’ll notice when you are doing push ups, you have a flush on your arms. While running, you might have redness in your legs. Blood is getting pumped to the areas working hardest. For runners, especially long distance ones, it’s constant and for great lengths of time. Then, BAM! You stop running. The blood that’s been flowing to other areas in the body,and not to the visceral (heart, lungs, abdominal organs) areas are now getting back the blood flow. This can really mess things up for your bowels, which at times has even caused a bit of bleeding after a race. But eww, right? You didn’t want me to GO THERE. Sorry.
Now, we’ll talk about the importance of hormones during exercise.
We’ve all heard the word CORTISOL. Usually it’s during those obnoxious commercials regarding “belly fat”. Cortisol is an important hormone. It helps promote protein and triglyceride (natural fats and oils produced by the body) breakdown during prolonged exercise.
ESTROGEN isn’t just for us ladies. It plays a major part in bone formation as well as maintenance.
EPINEPHRINE (my first thought was it’s use for allergic responses) increases cardiac output.
INSULIN helps to remove sugars (glucose) from the blood.
ALDOSTERONE limits salt in the urine to maintain an electrolyte balance during exercise.
VASPORESSIN reduces the amount of water excreted through your pee. Lovely.
GLUCAGON makes the free fatty acids release into your blood stream.
GROWTH HORMONE facilities protein in the body.
Now, let’s learn about the difference between AEROBIC and ANAEROBIC. Here’s the easiest. Aerobic is AIR. Anaerobic is NO AIR. So, if you are performing a movement that requires oxygen, you are performing an aerobic movement. If it’s anaerobic, you are performing a movement that does not require oxygen to produce energy. It doesn’t mean you aren’t breathing, or anything. It just means some movements need way more oxygen than others. Now, this can get confusing. Did you know that sitting and taking notes is an AEROBIC movement? And, running super fast for 60 minutes is ANAEROBIC? Aerobic requires more oxygen, but when you are performing a high intensity movement like sprinting quickly, you aren’t getting as much air in. Have you noticed? Everything revs up. It’s just impossible to breathe deeply, vs. sitting and taking notes allows you to breathe in as much as possible at a steady, even pace. So, I think of aerobic as the less hard movements, and anaerobic as the kick ass ones that gets your blood pumping hard, and you need to recover from. Plyometric jump squats? ANAEROBIC. Cycling for 20 minutes at an easy pace? AEROBIC.
Now, for people with chronic (remember, long term) conditions like asthma, exercise-induced asthma or emphysema, how does all of this limit their own performance? That much needed air we’ve been talking so much about isn’t able to move through the lungs appropriately. The lungs are constricted, and the blood isn’t oxygenated correctly. This limits how hard someone can work. Your brain is very sensitive to this disruption, and signals the body to stop working out. I have had exercise-induced asthma in the past. Running outside in the cold was never an option for me. I could barely breathe. The first step is to see your doctor. He/She may prescribe medication (inhalers) to you in order to help open up those airways. Working out in the cold isn’t an option. Cold air constricts the flow of air through your lungs, making it harder to breathe. However, I no longer have exercise-induced asthma. My body has overcome it through adaptation, and I can run outside in 20 degree weather with no issues. This may not be the case with asthma or with emphysema, so you should always seek out a professional opinion when it comes to making those first steps towards a new work out routine.