Very often, people are curious as to whether or not they can do cardio and still preserve and continue to grow hard earned muscle. The answer is yes but you have to be very organized about it.
Before I say anything else though, let me say - DO NOT do cardio on an empty stomach! It is very disturbing to me that people are so concerned with avoiding too much cardio so as to not burn muscle, but when they do it, they choose to do it on an empty stomach! You wouldn't weight train without your preworkout nutrition - this would be counter productive! Imagine waking up first thing, crawl out of bed and go start pounding the weight with no breakfast! Well, it is no different for cardio. You want to save muscle - feed it first and replenish it after. Now that's said....
It's all about the heart rate.
You need to find your resting heart rate before you proceed with the following calculation:
Sit in a semi-reclined position, relaxed and quiet. Find your pulse on your neck or wrist and count the beats for one minute. You can count for 15 seconds and multiply by 4, but I like counting for the entire minute. Write this number down. You will want to periodically check your resting heart rate and recalculate the following values because as you become more cardiovascularly conditioned and raise your endurance, your resting heart rate will change thereby changing the values at which you will want to maintain during your cardio sessions.
First of all, keep your nutrition tight. Nail down your pre/post and meal timing - keep protein high and carbs chosen wisely (glycemic index). You want to do cardio within the 65% to 75% of max heart rate for fat burning and muscle preservation.
Here is how to find your target heart rate:
1. Find your pulse and while relaxed and quiet, sit in a semi-reclined position, and count the number of beats per minute.
2. 220 - age = maximum heart rate (when you are here or higher - you are burning muscle!)
3. Maximum heart rate - resting heart rate...then...
4. Multiply this number by .65 (65% exercise intensity)...then...
5. + resting heart rate = target heart rate at 65% intensity (also figure 75% and 85%)
Here is an example for a 35 year old:
220
- 35 age
_____
185 = maximum heart rate
- 55 resting heart rate (example)
_____
130
x .65 exercise intensity (65%)
_____
84.5 (85)
+ 55 resting heart rate added back in
_____
140 = target heart rate at 65% intensity (figure also for 75% and 85%)
Here is an example for a 42 year old:
220
- 42 age
_____
178 = maximum heart rate
- 55 resting heart rate (example)
_____
123
x .65 exercise intensity (65%)
_____
79.5 (80)
+ 55 resting heart rate added back in
_____
135 = target heart rate at 65% intensity (also figure 75% and 85%)
A simpler way to find it, but less accurate, is to use this:
220-age=max heart rate
for example 220-42=178 max heart rate
178 x .65 = 115 target heart rate at 65% intensity
178 x .75 = 133 target heart rate at 75% intensity
178 x .85 = 151 target heart rate at 85% intensity
When lifting, don't allow your heart rate to exceed 85%. If it does, it indicates that the weight is too heavy and you are depriving your muscles of oxygen and upsetting the nitrogen/oxygen balance necessary for muscle.
85% can be utilized in a weight training program that integrates drills.
If your plan is tight and you are disciplined at keeping your nutrition anabolic and monitor your heart rate - you are good to go!
Oh, one more thing - don't hold on to the rails of the treadmill and don't be afraid of the incline - it is your friend
Happy fat burning
Before I say anything else though, let me say - DO NOT do cardio on an empty stomach! It is very disturbing to me that people are so concerned with avoiding too much cardio so as to not burn muscle, but when they do it, they choose to do it on an empty stomach! You wouldn't weight train without your preworkout nutrition - this would be counter productive! Imagine waking up first thing, crawl out of bed and go start pounding the weight with no breakfast! Well, it is no different for cardio. You want to save muscle - feed it first and replenish it after. Now that's said....
It's all about the heart rate.
You need to find your resting heart rate before you proceed with the following calculation:
Sit in a semi-reclined position, relaxed and quiet. Find your pulse on your neck or wrist and count the beats for one minute. You can count for 15 seconds and multiply by 4, but I like counting for the entire minute. Write this number down. You will want to periodically check your resting heart rate and recalculate the following values because as you become more cardiovascularly conditioned and raise your endurance, your resting heart rate will change thereby changing the values at which you will want to maintain during your cardio sessions.
First of all, keep your nutrition tight. Nail down your pre/post and meal timing - keep protein high and carbs chosen wisely (glycemic index). You want to do cardio within the 65% to 75% of max heart rate for fat burning and muscle preservation.
Here is how to find your target heart rate:
1. Find your pulse and while relaxed and quiet, sit in a semi-reclined position, and count the number of beats per minute.
2. 220 - age = maximum heart rate (when you are here or higher - you are burning muscle!)
3. Maximum heart rate - resting heart rate...then...
4. Multiply this number by .65 (65% exercise intensity)...then...
5. + resting heart rate = target heart rate at 65% intensity (also figure 75% and 85%)
Here is an example for a 35 year old:
220
- 35 age
_____
185 = maximum heart rate
- 55 resting heart rate (example)
_____
130
x .65 exercise intensity (65%)
_____
84.5 (85)
+ 55 resting heart rate added back in
_____
140 = target heart rate at 65% intensity (figure also for 75% and 85%)
Here is an example for a 42 year old:
220
- 42 age
_____
178 = maximum heart rate
- 55 resting heart rate (example)
_____
123
x .65 exercise intensity (65%)
_____
79.5 (80)
+ 55 resting heart rate added back in
_____
135 = target heart rate at 65% intensity (also figure 75% and 85%)
A simpler way to find it, but less accurate, is to use this:
220-age=max heart rate
for example 220-42=178 max heart rate
178 x .65 = 115 target heart rate at 65% intensity
178 x .75 = 133 target heart rate at 75% intensity
178 x .85 = 151 target heart rate at 85% intensity
When lifting, don't allow your heart rate to exceed 85%. If it does, it indicates that the weight is too heavy and you are depriving your muscles of oxygen and upsetting the nitrogen/oxygen balance necessary for muscle.
85% can be utilized in a weight training program that integrates drills.
If your plan is tight and you are disciplined at keeping your nutrition anabolic and monitor your heart rate - you are good to go!
Oh, one more thing - don't hold on to the rails of the treadmill and don't be afraid of the incline - it is your friend

Happy fat burning