Fitness & Exercise Community

Rocketqueen,


I will discuss this issue with you but not if you carry on, if you are rude, or if you attempt to insult me. If you'd like to have a calm, respectful, rational discussion based on the facts and science, I am happy to do so.


What you are looking at is something called postexercise oxygen consumption or EPOC. This is the amount of oxygen consumption following exercise. RER is the respiratory exchange ratio and it tells you the percent of fat being burned, and so it's important when you're thinking about fat and weight loss in relation to exercise. Both of these are important when considering the metabolic rate after exercise.

I have done literature reviews in the past on this subject and do not intend to do another one, but I have posted a few study abstracts for you that are representative of the literature that exists on this subject. In addition, I have tested many people myself in our metabolic chamber and the metabolic rate the majority of the time returns to baseline within 20-30 minutes after bouts of 30-40 minutes of aerobic exercise, whether the person is lean or obese.

I want to repeat my earlier post and say to you that high intensity aerobic exercise (such as intervals) will raise metabolic rate at most for a few hours after exercise, and lower intensity may raise it for as little as 30 minutes. Of course, during both high and low intensity exercise metabolic rate rises as you burn calories to fuel the activity. Resistance exercise, on the other hand, can raise metabolism for many hours, and in some cases, when the exercise is very intense, it could be as long as 10-12 hours.

In this first study abstract I have for you you will read that the data shows that the intensity of the aerobic exercise is the main factor that affects EPOC. You will see that EPOC after high intensity exercise will last for only several hours, and not all day or overnight, and at lower intensities, like most people train at, the effect is minimal. Like I said, high intensity interval training will have more of an effect than lower intensity, but it still only goes for a few hours at best. Here's the link
http://www.ncbi.nlm.nih.gov/pubmed/14599232

If you read the abstract of this study carefully you will see that the EPOC did not last more than 33 minutes. http://www.ncbi.nlm.nih.gov/pubmed/2626089

In this one the EPOC did not last more than 27 minutes.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1478795/

In this recent study from 2011 http://www.ncbi.nlm.nih.gov/pubmed?term=Excess%20postexercise%20oxygen%20consumption%20is%20unaffected%20by%20the%20resistance%20and%20aerobic%20exercise%20order%20in%20an%20exercise%20session
the investigators used a combination of resistance (3 sets 10 reps 5 exercises) and aerobic exercise (30 minutes on a treadmill). The respiratory exchange ratio decreased to lower than the baseline within 10 minutes of stopping exercise.

If you'd like to do your own research on the topic and post back some of the articles that you find, or that you have already read, that show that metabolic rate stays elevated for 12 hours or more after aerobic exercise, or that it lasts until you go to bed, even if you exercise at 9:00am, then I am happy to look at them and make comments. But again, I will not respond unless you agree to have a calm, respectful, and rational discussion based on the facts backed up by science.

Rich

Rich,

Post resistance training, does elevated heart rate accompany the elevated metabolic rate, several hrs after completion of workout?

Most people associate stress relief with blood pressure...Does blood pressure normally increase or decrease during the recovery period after resistance training? Aerobic training?

Second question, in the treatment of chronic anemia, assuming proper supplementation of key minerals and nutrients, is one kind of exercise better than another? Do you believe there's a relationship between impaired blood oxygenation and cancer and, if so, do you believe exercise should be recommended in the treatment of cancer. This question is in reference to recent relapse of cancer for ESPN anchor Stuart Scott and his daily regimen of P90X.

Thank you & look forward to your response.

Hi Brunosbud,

1. Heart rate could remain elevated afterward, but it's not a perfect correlation with metabolic rate (your heart rate could return to baseline while your metabolic rate stays elevated). Recovery heart rate is a good predictor of fitness and even mortality, and so it's a good thing when it returns to baseline quickly.
2. BP will return to normal after weight lifting almost immediately, within seconds after a set.
3. With anemia you just need to pace yourself. There's no one exercise that's better than another. Sometimes you'll have more energy than other times. Sometimes resistance exercise will be easier than aerobic training. You have to listen to your body. You can read more about anemia here http://www.webmd.com/a-to-z-guides/understanding-anemia-basics
4. I don't know anything about blood oxygenation and cancer. But exercise has been shown to reduce the risk of colon and breast cancer, and some studies suggest that it can also reduce the risk of lung, prostate, and endometrial cancer. Many people believe exercise improves quality of life in cancer survivors; I don't know the studies on this, but it makes sense to me. Exercise improves the immune system and boosts lymphocytes like natural killer cells. That can explain some of the mechanism for the cancer prevention. There's lots more to be learned.

Hope that helps.
Rich

Thanks for your reply, rich.

In your studies, you indicate that O2 Consumption is the method used to measure a rise in Metabolic Rate. Yet, it appears based on what you mention, above, that a rise in metabolic rate doesn't necessarily require a rise in heart rate. What does that say about Red Blood Cell counts, Iron and Hemoglobin levels and how does it impact weight loss?...

How did Erythropoietin, steroids, and blood transfusions help Lance Armstrong win 7 Tour de France and make him a billionaire?

PS: rocketqueen, we're still waiting for your response. thx...

You're welcome brunosbud. You can have a rise in VO2 without a significant rise, or virtually any rise, in heart rate at rest. What it means is that the muscles are "consuming" oxygen; that is, oxygen is transported across the cell membrane to burn fat (fat oxidation), but heart rate doesn't necessarily have to be elevated for that to happen. It happens during exercise of course, but it doesn't have to be the case at rest. Athletes can have high metabolic rates but very low heart rates. Red blood cells, iron, etc, are different, although hemoglobin transports the oxygen, but I am not sure the correlation between hemoglobin and metabolic rate is typically measured. I don't know what the correlation is. As for Lance, well, I don't know all that he was taking, but erythro certainly helps transport more O2 to the cell, and the steroids made him a monster. His oxygen consumption I believe was measured at 92ml/kg/min. There are very few humans who do that. X-C skiers are known to be the fittest athletes in the world in terms of oxygen consumption, and some of them have been measured in the mid-90's, but this is extraordinary and very few athletes achieve this level. Mainly you get mid- to high 80's for extremely fit athletes. For perspective, a very fit person in the gym who is not extra-ordinary could get up in the high 60's. The maximum for a sedentary person is around 30. We've measured sedentary individuals in our lab at 20! This is very unfit. I'm not sure Lance will have billions after he gets his legal bills.

Hope this helps.
Rich