Fasted running

Fasted LISS? Sounds like a recipe for muscle loss and high cortisol levels.

If your goals are centered around running then eat a healthy meal an hour or so before you run. If your goals are centered around body composition then eat a meal an hour before you train and stop running. Instead, lift weights and do HIIT. I would recommend a heavy bag, prowler, sledge hammer, kettlebell or a heavy carrying implement (this could just be a big rock) for your HIIT.

I have distance running goals, so I won't be stopping running any time soon. Not all of us want to be powerlifters, bro.

Fasted LISS? Sounds like a recipe for muscle loss and high cortisol levels.

If your goals are centered around running then eat a healthy meal an hour or so before you run. If your goals are centered around body composition then eat a meal an hour before you train and stop running. Instead, lift weights and do HIIT. I would recommend a heavy bag, prowler, sledge hammer, kettlebell or a heavy carrying implement (this could just be a big rock) for your HIIT.

I have distance running goals, so I won't be stopping running any time soon. Not all of us want to be powerlifters, bro.

I run 5 times a week; 2.5mi Tues, Weds and Thurs, with longer runs of 4-5 miles on Saturday and Sunday. On my weekday runs I go after work, so about 3 hours after a small lunch of couscous or pasta, but on the weekends I usually go in the morning without eating anything. As my runs get longer I'm concerned I might not be fueling myself properly.
The problem is the two attempts of me eating before a run (first was a boiled egg, second was a protein shake) ended up with me having to stop to puke, It seems my body can't cope with digesting anything as I'm running. Am I doing myself any harm working out after not eating for 8+ hours? Should I keep trying to eat something and just power through the puke?

Lofteren-OP's entire post is about RUNNING.

perhaps YOU didn't read the entire post!

Am I doing myself any harm working out after not eating for 8+ hours? Should I keep trying to eat something and just power through the puke?

OK! Here is my skinny on fasted and unfasted running.

First some fueling tips if you do decide to eat before running.

Try different things. Different people react to different foods differently. You want to experiment in training runs so you know what works and doesn't work as you prepare for races. When you find something that works, you gonna want to replicate that before a race. This includes your day before pre-race meal.

Eating too many calories before a run can lock up your stomach pretty bad and cause discomfort. As you run, blood is being diverted to the areas that require oxygen and liver glycogen and fat absorption during your run. This blood is diverted away from other functions such as digestion. I go by Runner's World Big Book of Marathon and HM Training. 600 calories approx 3 hours before a big run in simple carbs or 200 cals 1 hour before. As you are running, 100 cals 30 minutes into the run and 45 minutes thereafter.

Why fuel up as you are running? As your body uses the anaerobic system (burning fuel without the presense of oxygen) you will be burning up your internal carb stores (glycogen). You have a limited supply. Different people have different levels and it depends how intense you run, but for most experienced runners, they should be able to run 15-20 miles and even beyond without worry of bonking (clearing out their glycogen supply). Running way beyond your aerobic threshold or poor training may cause you to bonk much sooner. The idea is to supplement the amount of glycogen you use up as you run but not replace it all together during the run. If you bonk too fast, then you are running faster than you should for your goal distance.

If you run at a pace that is below your aerobic threshold (burning fuel in the presense of oxygen) then your fuel supply relies more on your internal fat storage as opposed to glycogen. Your body (in comparison to gycogen) has a virtual endless supply of fat to fuel long term activity.

So this leads us into training and especially fasted training.

If you have long steady training runs that you rely on your aerobic system, your body will begin to learn to rely more on fat burning as opposed to glycogen burning. Training fasted during these runs will slowly deplete your glycogen and will stimulate growth in this area. In other words, your body will soon learn to store more glycogen for future runs. As you sleep, your body begins to use up and lower your blood sugar. When your blood sugar goes below a certain point, it may either use fat or glycogen to fuel your bodies survival mechanisms as you sleep. If you train to rely on fat burning, your body will burn less glycogen but it will burn some glycogen none the less. So unless you eat something in the morning before you run, you will have diminished glycogen stores.

This could be a good thing tho if you don't mind diminished performace in trade for stimulating growth.
At a certain point, your body will experience diminished returns and poor performance will outweigh the benefits of stimulating the growth of glycogen storage. But in the beginning of the training season, the diminished supply of blood sugar and glycogen during fasted runs will take some getting used to as your body learns to power from your fat storage and aerobic system.