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[bigiz123]

I do cardio basically monday thru friday (five Days) for about 45 minutes, i usually take the weekend off, so my question is if my cardio schedule is fine, or if it needs any adjustment? also, if i do cardio for an hour, is it true that i will start losing muscle as well?

[Tredo]

Yes, there's long duration, low intensity cardio; that is the kind of cardio that does not do much for you and you lose muscle mass. Try High Intensity Interval Training. You can increase your endurance, keep muscle mass and do it in less time (around 20 minutes -- max!). If you do High Intensity Interval Training, you wouldn't have to do cardio everyday; three times a day would be sufficient.
Well, that's all I know. I might've made a mistake. It's best to wait for swans05's reply.

[swanso5]

your mostly right there tredo good jog...

Low Intensity Cardio
- good if your on a low calories / low carb etc diet as anything too intensive will use muscle
- good if a little sore from previous workout
- can do if carb-fasted (but with a sml protein and water shake beforehand in morning) for fat loss
- too long with not enough cal's will use muscle as energy = not good

High Intensity Cario (intervals, sprints etc)
- good for preserving muscle mass
- not the best on low cal diets as they require a lot of cal's to do it
- not good carb-fasted either
- methods such as sprints and high resistnace intervals on the exercise bike can even build muscle as they are very anabolic and the best option for fat loss and endurance i think

Conclusion
mix it up...i would do this;

session 1 - sprints x 5 - 10...sprint as far as you can holfd your TOP spped...when you start to slow stop and get almost full recovery between reps but not quite...posted something yesturday here about this with heart rate details so check that out
session 2 - low int, long duration cardio but no longer than 45mins
session 3 - interval training doing 10mins in total with 90secs as easy as you can then 30secs as hard as you can...details of this are also on yesturdays post
session 4 (optional) - either repeat 2 or 3 depending on how you feel but i would add it in later when fat loss stalls deoending on what your training for

[bigiz123]

is it ok if i basically only do HIIT and sprints? 20 minutes max? on a bike?

[swanso5]

in that case do 1 sprint session all out and 2 HIIT sessions or 1 all out sprint, the 2nd 70% sprint session and 1 HIIT session...your choice there both good