Treadmill workout advice?

I've been going to the gym for about 7 weeks.  Mostly use the treadmill, but also do some weights, and swim.

I was doing manual on the treadmill and walking. trying to get faster/go farther every workout.  usually between 3.0- 3.6mph.  Well, I went on the "good" treadmill it has all the bells and whistles. 

I started playing with the programs and have been using the "fatburn" program.  I like how I get to the "zone" and stay there. I do sweat, and ya my muscles feel it after the workout. I don't get that crazy out of breath, wow, that I did before.

Today I did 75min plus a 5 min cool down. My heart rate stayed between 122 and 130. (the target according to the machine is 119).  It said I burned 547 calories. 

Can someone please  better explain cardio vs fatburn.  I feel like I am cheating since I have been going faster for the past  weeks.  With the fatburn I feel like I could go longer, I am comfortable. Should I push myself more. I am in horrible shape so to achieve 119bpm doesn't take much. @ 3.4mph I go beyond target pretty quickly, right around 3.0 keeps me around 125ish.

Any advice will be appreciated.
Thanks
Michelle

There was an article on Yahoo recently about just this question.  I can't find the exact article right now, but this is pretty close and covers the info.

QUESTION:

I have often heard that you need to exercise at a low intensity or low heart rate to get into a "fat-burning zone" that will favor a loss in body fat.  Is this true?
ANSWER:

The "fat-burning zone" is one of the many misconceptions that seem to be passed from one exerciser to another.  The explanation for the myth is a combination of misinterpreted biochemistry and exercise physiology, inadequate education of many workers in the fitness industry, and a magazine culture that often favors sensationalism over scientific fact.

Let's start with a brief explanation of where this belief comes from.

Our body uses a mix of fat and carbohydrate to fuel the energy needs of our cells.  Researchers can quantify this mix with high accuracy in an exercise physiology laboratory using expired gas analysis.  The percent contribution of fat and carbohydrate does indeed vary depending on the intensity of exercise.

For instance, when we transition from rest to exercise, there is an increase in energy expenditure (i.e., calories burned) to meet the increased needs of our muscles.  When the exercise is of a low intensity, our bodies preferentially use fat as a fuel, similar to a resting state.  Thus, low intensity exercise does predominantly rely on fat to fuel contracting muscles.

As the exercise intensity increases, added neural stimulation, hormone concentrations, and a complex regulation of muscle metabolism causes a progressively increased dependence on carbohydrate catabolism.  The greater the increase in exercise intensity, the greater the dependence on carbohydrate until eventually only carbohydrate is used by muscles to fuel contraction.

The misinterpretation stems from overlooking the fact that the total amount of fat used during exercise is actually a combination of two variables:

1. the proportion of fat used to fuel the muscle contraction
2. the total energy expended during exercise.

If you only rely on low intensity exercise to burn fat during exercise, then your total calories burned per minute will be low.  Thus, you would have to exercise for a long time to burn a significant amount of fat.  Conversely, exercising at a higher intensity, even though the proportion of fat contribution is lower, can result in a similar fat combustion because the total amount of calories burned is higher.  The following table highlights this comparison.

Examples of computations for fat loss during exercise at different intensities.

Exercise Intensity Calories* Fat % Carb % Fat Lost (g) Low 213 85 15 20 Moderate to Vigorous 555 30 70 18.5

* Energy expenditure (calories) based on a 45 min constant intensity workout

As you can see, even though the percentage of fat contribution differs, exercising for 45 minutes at a low intensity vs. exercising at a moderate to vigorous intensity will expend nearly the same amount of fat.  However, the moderate to vigorous exercise intensity workout is further benefited by more than double the total calories burned!

The key to understanding body fat reduction from exercise is to follow this simple rule:

Caloric balance = energy ingested - energy expended

The body fat loss from exercise is based, not only on the fat burned during exercise, but also on the caloric deficit you generate from a sound diet in combination with adequate exercise and physical activity.

It should also be noted that higher intensity exercise training results in greater training adaptations as compared to those seen with lower intensity workouts.  For instance, higher intensity workouts result in greater changes in muscle structure and function, as well as cardiovascular system structure and function.  These changes improve endurance fitness.  This is great news because fitter bodies utilize a greater percentage of fat calories throughout the day, both during exercise and at rest!  In addition, being fit will allow you to exercise at higher intensities for longer, resulting in increased calories burned during subsequent workouts.

So take the focus off of working out in the low-intensity "fat burning" zone, and focus on the overall quality of your workout.  If you are a beginner, you will need to start off with low-intensity exercise.  However, as you become more fit and adapt to your exercise sessions, you can start incorporating higher intensity bouts into your workouts, thus reaping more benefits.

MYTH: The calorie readout on machines is accurate.
REALITY: If only! Research has shown that some types of machines can be off by as much as 70 percent. The culprit? Contraptions such as the elliptical machine haven’t been around long enough for exercise scientists to develop the appropriate calorie-burn equations. On the upside, stationary bikes and treadmills, the grandfathers of the gym, generally give a fairly precise reading, particularly if you enter your age and weight.

Rather than swearing by what the machine says, use the calorie readout to monitor your progress. If the tally climbs during the same workout for the same duration, you’re working harder and getting fitter. An online calorie calculator can give you a sense of which activities burn the most.

Hope this helps.

Scott

Scott spelled it out nicely.  Most important is not to injure yourself so start slowly but push yourself a bit, as you get fit I recommend doing some higher intensity workouts.  I love to do interval sprinting in my anaerobic and max heart rate zones.  It burns a ton of calories, boosts your metabolism so you burn more fast over the next 24 hours, and increases your fitness level.  I mix it up, sometimes I'll do:

3 -5 min warm-up at level 3.0-5.0
then 1 min at 6.0-6.5
then back to 1 min at 3.0
then back up to 1 min at 6.0-6.5
(I will alternate between these 2 for 30 minutes)
then 3-5 minute cool down.

Or, I might do an even higher intensity for shorter intervals alternating 30 seconds at 7.0 and 30 seconds at 3.0 or even 15 seconds at 8.0 or my all out fast as I can sprint and 15 -30 seconds of rest and I'll do this for 10-15 minutes.  The shorter sprints are easier to do outside than on a treadmill. Then I'll continue on in my aerobic zone for another 15-20 minutes so I get at least 30 minutes over-all of cardio.

Now you may not be able to go that fast at first but even on lower speeds your heart rate may get up in the anaerobic or max zones during your sprints, which is what you want, so that means you are going fast enough.  I usually do 2-3 of these interval sprinting runs a week and I do longer more steady runs/walks 1-2 days.

 

I hope that helps keep up the good work.

Thank you both for your replys. 

I am going to push myself harder.  I am going to look at the on-line users manual for the treadmill that I use at the gym and see if there is a hill program or interval program that I can use.  If I get too out of breath etc i can always take it down a notch.   

All the best,
Michelle

Michelle,

The other thing that is just coming out from the research is that higher intensity workouts lead to better heart health and decreased risk for heart disease.  After all, that's the main goal, to be healthy.  As it turns out, you are more healthy if your fitness level improves.  It is better for you to do 30 minutes of moderate intensity exercise than it is to do 60 minutes of low intensity exercise (what they would consider the fat burn heart rate).  In fact, 20 minutes of high intensity is equal to or better than 30 minutes of moderate. 

The more studies they do, the more they realize that the maximum benefits of exercise come from a mixture of high and moderate intensity as well as strength and flexibility training.  I'm not even looking at it from a weight loss vantage point,.  It's all about overall health.  My last lipid panel showed HDLs at 99 and LDLs at 68 with triglycerides a mere 88.  All this is from moderate intensity exercise with a good mixture of higher intensity added in.

Hope this helps.

Linn