Fat burning zone and low intensity training

Community Leader
Registered: 04-05-2002
Fat burning zone and low intensity training
7
Mon, 11-11-2013 - 5:07pm

This might get technical but there's an every day question based in this so hang with me, please?  The whole idea of working at a lower intensity to burn fat was debunked as a myth. It's about calories. Or is it?  I've read quite a few books about endurance athletes who have to work at lower intensities because they need to teach their bodies to burn fat as fuel and working too high, they won't, That makes sense, But, I was also told at Spinning/Mad Dogg Cert that you can't work too high for the same reason.  The instructor talked about how she had her VO2 max test done and that she doesn't burn enough fat at lower level intensities so she needed to work there.  She did, lost 15 lbs. This is the theory pushed by companies that market the equipment and one that my boss believes in.  She's done it herself but also changed her diet (ding, ding).  

So, the non -technical question is how to deal w/ this dichotomy. She pushes all clients to work at lower intensities.  I can see it working if they go for longer. But, what I've read is that if you burn glucose during exercise, your body will refuel the glucose by burning fat. That makes sense. It was really tricky today because at the hospital, a client asked me that. The doctor told him it's all about calories. The nurse said it's about working at lower intensities.  I don't want to disgree w/ what my boss said but it's a challenging line and I end up sounding ineffectual. Talking to my boss isn't going to work. She's one of those people who thinks she knows it.

And, the second part of it is, for those of you who follow this, what do you think?  Is there an advantage to working in that zone?






iVillage Member
Registered: 03-15-2004
Mon, 11-11-2013 - 5:57pm

Oh, that's tough.  I too learned that it's more about total calorie burn regardless of where the energy originates.  

I try to take the view that all forms of aerobic training are useful so it's best to do them all (kind of like having a varied meal - meats, veggies, etc.).  

There's still a lot we don't know about aerobic training, glycogen synthesis, etc.  You could always use that...  "It's my understanding that xx and yy but there's a lot we don't know."

Community Leader
Registered: 04-05-2002
Tue, 11-12-2013 - 7:18am

That's exactly what I say, too.  And that there are studies that show both but overall, if you're limited in time, you want to max calories burned.  Plus, there's EPOC that has been shown to burn up to 15-20% more calories after we've worked out when we do HIIT.  I tell them that running training programs cover a good spectrum, from short interval speed work to longer temp runs (comfortably hard where you just skirt the anaerobic zone) to long slow runs. It all sounds indecisive when I tell them.  Then again, I have the same problem w/ diet advice.  My boss believes low carb, high protein and I think it's all about calories.  But, maybe not. There's too much that we don't know!






Community Leader
Registered: 04-07-2008
Tue, 11-12-2013 - 8:44am

I am no science/health expert so all I  can say is from personal experience. The majority of my workouts are low intensity because I am far more comfortable than with high intensity workouts. I have a lower amount of body fat than a lot of women my age (just recently had a test that put me at 15 %). The other women I know at my gym who are lower body fat also tend to stick to longer low intensity workouts. The ladies who stick mainly to the high intensity workouts tend to be heavier than us, but I have always thought it was more a problem with their diet than with their exercise regimen. 

Karla
Community Leader
WALKING
EXERCISE and HEALTHY LIVING

Community Leader
Registered: 09-25-2003
Tue, 11-12-2013 - 5:01pm

In prior years, physicians were taught to treat each patient as an individual, edifferent slightly different solutions.  Case in point, some patients react better to different meds, even from within the same class of drugs.  I think that is what igliding on, here.  GR has a point that how we metabolize sugar, if we are pre diabetic and our bodies are producing high amounts of insulin and if our liver is spilling sugar even when we eat (aka type 2 diabetes), along with glycemic index of food, etc, will all have an effect.  Heck, there are certain things going on in our bodies that we still have yet to learn.  I, personally, am with Karla, when I work out too intensely, as I once did, I tended to be hungrier, and, therefore, I was heavier.  Now that I work out at a less intense level (I.e., yoga,) I have been able to lose weight.  I am also pre diabetic, which I think plays a role in the equation.  How is that for a wispy washy response?!

Community Leader
Registered: 04-05-2002
Tue, 11-12-2013 - 5:29pm

Anecdotally I see what you're saying because I see it, too, although I do see thin women do high intensity. I think it's genetics, actually.  If you have more slow twitch muscles, you're less likely to put on muscle mass and you prefer to use the type of muscles you were given.  If you have more fast twitch muscles, your muscles are more likely to get bigger but it's also your preferred exercise.  Think of marathon runners vs football players. It's not the actvity as much as it's the body type that is drawn to the activity.

And, yes, diet plays a far bigger role.






Community Leader
Registered: 04-07-2008
Tue, 11-12-2013 - 7:03pm

Jean that does make sense that our body types would lead us the activities we can do best because of how we are built. That would definitely explain why you see more of certain body types at a particular activity than another. 

Karla
Community Leader
WALKING
EXERCISE and HEALTHY LIVING

Community Leader
Registered: 04-05-2002
Tue, 11-12-2013 - 7:34pm

Not at all wimpy.  I think it's definitely true and there are fields like nutrigenomics that study it.  It needs to be person based but we can only tell at this point by experimenting.  My personal theory, which I would love someone to test, is that a big part of it, in addition to diet as you said, has to do w/ our muscle fibers. Slow twitch muscles, as Karla obviously has, burns fat for fuel while fast twitch muscles burn glucose for fuel.  The more fat you burn, the thinner you'll be.  The proportion of each type of fiber is genetic but we can work the other group more to develop it more. So, you probably have more fast twitch muscles but when you work the slow twitch ones, you grow those and burn more fat.  IMO, that's the "fat burning zone."  Larger/more (converting those "in between fibers to slow twitch) slow twitch=more fat burned.