I run and I weight Lift. Altho, I've been weight lifting more lately...
So...If I run in the Morning...What would be the first to get burned off...The Muscle Mass or the Fat.
I understand that it's better to run in the morning cus your body goes straight for the Fat and not just energy.
But how much would that affect my Muscle Building?
The body is a machine that constantly uses fuel for it's needs. It's generally understood that you have 3 forms/storage of energy:
Creatine-Phosphate/ATP
Glycogen
Fat
It's a misunderstanding to figure you only burn one of these at a time; you don't have a fuel-selector swicth. At any given time your body is using a combination of these 3 sources. The mixture depends on your needs (demand) and where your blood-sugar level is at...that and several other factors.
If you eat or drink something that has calories, then as it digest it can be used to fuel exercise. In the morning, prior to eating, you won't have any contribution by means of consumed nutrients...but that doesn't mean your body will entirely revert to fat as a sole means to fuel your exertion (running in your case).
Your body seeks to maintain a certain blood-sugar level...this glucose in the blood will be used for body functions and your running. The liver also stores some glycogen as well as your muscles. As soon as you start running you'll start burning-up these sugars and the body kicks into supply mode by meeting your demand through accessing various energy sources/reserves. Again; it will not go solely to fat as a means to fuel your running, it will use a combination of sources to fuel your needs.
It seems we currently subscribe to the notion that we require 20 minutes before the body starts to tap into the fat.....but I'm told this just isn't accurate and unless your blood-sugar is high and the body is storing energy, we are constantly going back & forth with storing and using our fat as an energy source/storage. But yeah, after some 20 minutes we generally cut into the blood-sugar level and some glycogen in the muscle...so at an increased rate the body will start to spin-up some fat-energy to meet the demands of your exertion.
I think I over-answered your question...but suffice it to say you don't cut straight into your fat when you get up and run on an empty stomach. Without food in your stomach, you'll sooner get to your fat....but that brings-up the notion that fat burns in a carbohydrate flame and you'll have better peformance and overall burn more calories by eating a bit of food before you run. In the end, the trend/notion of exercising on an empty stomach has gone the way of disco.
Your other concern is that you'll burn your muscle as fuel. This is catabolism....and the general trend is to presume your body will turn to it's own muscle to use for fuel. Okay, as mentioned, this only happens in extreme instances and only after way-extended long cardio duration when you've pretty much depleted your glycogen and your bonking. This is very unlikely to happen to you...especially if you're keeping your calorie deficit to no more then 20% and eating a well-balanced diet....and not doing marathons or exercising for ridiculous periods of time.
My suggestions based on my own experience:
Alternate your cardio days with your weight-training days!
Many would argue that it's more beneficial to do 6 hours of cardio spread-out over 5 days, but not if you're doing weight-training on the days your not doing cardio!
With cardio I prefer doing 2 to 3 sessions per week of 2.5-3 hours per session tappering down with lower-intensity and long-duration cardio; I believe and have found this is where your body can really burn some fat in higher propotion. As you get longer into your cardio (and deeper into your glycogen reserves) your body is more inclined to source fat as a fuel, especially if you keep the intensity on the mid to lower range. You don't want to do intense cardio for more then an hour, just like weight-training, it's very demanding and this is where you can approach catabolism. So hit the cardio every other day.
Another idea is to run or bike for 2/3-3/4 of your cardio session...this will use your largest muscles in the body; you can easily run your heart-rate up way high and burn some serious calories. For your last 1/3-1/4 of your session, transition to swimmming. Your arms are far smaller in muscle and even vigorous swimming can't tax your heart-rate like the leg muscles. When I kayak (rubber leash holding me in place)...I can't get my heart-rate over 128 no matter how hard & intense I paddle! For long-duration cardio, this is perfect....from a proportion standpoint this will really allow you to tap into your fat and utilize different muscles as well. Swimming will lean you out nicely too and it's realy low-impact and very refreshing!
On weight-training days, hit it fresh and with a good meal under your belt...rip it up, push it hard and make some progress. If you want, you can follow it up with 30-45 minutes of cardio to take advantage of your low blood sugar condition (where your apt to burn a good deal of fat)...but if you pushed yourself wicked-hard, then don't do the cardio. The important thing is to "put it back" asap: get a good quality protein shake and give your body & muscles everything it needs to replenish what you just burned-up. So long as your muscles get some protein and glycogen, they will build. And yes, you can build muscle while in calorie deficit!..and on that subject...
You can build muscle AND lose fat at the same time. If you go into your weight-training with some good calories under your belt AND you follow it up with some a solid protein shake, some good food and supplements, then you will build muscle....provided you don't starve yourself the rest of the day. Don't exceed a 20% calorie deficit, it could inhibit your muscle growth.
On the flip-side...on cardio days, eat a bit going in and don't be afraid to follow it up with some calories, about 1/3 to 1/2 of what you burned. Watch your diet this day, but remember, you're doing weights tomorrow so eat right and focus on that 20% deficit.
So, weight-train but slap it & back it with solid protein shakes and some calories: eating after exercise is a good time to eat....your body will store the calories back into the glycogen and sometimes it seems like it bumps your metabolism (you'll know this is happening when you find yourself sweating as you eat and right afterwards!). Weight-train in the morning, back it with food, a medium meal later in the day and lean it out a bit into the evening: nutrient timing!
Everybody's body responds differently...so figure-out what works for you. My body has been very stubborn & challenging; only when I get things right do I get results, and what I've covered here seems to have worked well for me.
