Cardio Question: This is a puzzle I cannot figure out

[Genius]

I have been lifting for 7 years now. I would like to think I have the resistance training portion of my physical fitness routine down. There is one thing that totally puzzles me though when it comes to cardiovascular exersize. I have done sprints, and I have done distance. I have heard theories that claim HIIT is the ONLY way to go. I have never heard anything negative about HIIT except the fact that it does not give your heart the same benefits of a long distance run. In theory, HIIT uses short bursts of energy (sprints) of up to 8 seconds in duration, followed by a resting period of around 45-60 seconds, followed by another burst of energy (sprints). I've heard that this is suppose to burn fat very fast, while preserving the muscle. On the other hand, I've heard that distance running burns fat for only the first few seconds, and from that point on muscle tissue and fat are both consumed. I have done both. I would just like to hear some opinions (I would prefer someone with a lot of knowledge on the topic...at least more than I have). Which is best for fat burn? Is HIIT just some theory some trainer-gone-mad thought up, or is it the real deal? Is distance running really not good for fat burn, and does it really hamper muscle growth as some claim? Any scientific research and backing would look even better with a response, but opinions would be helpful too. Thanks for the time and the thought...this is a topic in which I have found both sides to be equally strong, it is pretty difficult to choose when each way seems so just. I simply want to know what is the best for burning fat while preserving muscle? Thanks a million.

[10iscoach]

Aerobic training at very high intensities through its effects on mechanisms associated with peripheral adaptations may be the cause of blunting of strength gains and hypertrophy when aerobic training is done along with resistance training.

[poopy pants]

[bryanc]

Originally posted by 10iscoach:
Aerobic training at very high intensities through its effects on mechanisms associated with peripheral adaptations may be the cause of blunting of strength gains and hypertrophy when aerobic training is done along with resistance training.

I'm not personally a big proponent of HIIT, but that's a pretty general statement. I think you'd have to define what you mean by, "high intensity", "mechanisms", "peripheral adaptations" and "blunting". The literature is pretty confused when it comes to concurrent aerobic and strength training--there are no clear answers yet.

[10iscoach]

That is why I made the statement "may be the cause" This is the currrent theory not fact.

[fitone]

The literature is pretty confused when it comes to concurrent aerobic and strength training--there are no clear answers yet.

In the end all exercises are theroies mention by 10iscoach. Bottom line is do what works for you.

[10iscoach]

The basic theory holds that high intensity aerobic training such as interval training affects specific mechanisms in peripheral adaptations such as those involved in increasing a muscle's oxidative capacity while a resistance training protocol for hypertrophy would try to increase protein synthesis and also stress the anaerobic energy system.

The combination of the two training protocols is literally trying to force the muscles to adapt in very different ways.

However, adaptations to steady state aerobic training below the anaerobic threshold may be primarily central and have little or no interference with strength or hypertrophy since different mechanisms are involved.