interval training

Question
QUESTION: Hi, i've decided to start with interval training because well according to many sources it burns fat more efficiently and also i've been jogging for almost 2 years so boring. So i have a few questions hope this is in your area. 1st seems like interval training is sooo good.. for example burns fat better you dont need to do as much HIIT as normal jogging to get results seems too good to be true what are the down sides? if there's one of course. 2nd is it bad for your knee? i mean you're gonna be changing speed so much would it injure your knee or any body part?. 3rd I used to jog 5 times per week but i've heard that when doing interval training you have to rest a day or more before doing it again is it true and why? 4th what is the best routine? do you recommend? btw i dont have a tredmill thank you!

ANSWER: A great question. Please forgive me, my computer recently crashed and it's hard to get to these questions right now.

First off, interval training does differ from jogging. It will probably raise your heart rate more, and you'll get a better workout. But intervals are for tweaking, not weight loss. Intervals are for improving your vo2 max, lactate threshold, and efficient oxygen consumption by your muscles. The most important thing you should remember is that you are trying to burn maximum carbohydrates. And when doing interval training, you are tweaking your efficiency rather than getting in quality carb burning time. So no, it doesn't necessarily burn fat better.

The next question, well, there's nothing to it. When comparing interval training and jogging, let's just say in an interval workout you run a total of 1 mile. And in your jogging session you run a total of 5 miles. Well we know that your footstrike was more rapid in your interval workout. So just do the math. Did your foot strike as many times in your interval workout than your jogging workout? Probably not. So to answer your question, there's no difference in how either affect your knees. The only thing that affects your knees is the high mileage. Just don't do too much running on asphalt or concrete and you'll be okay.

Rest time depends on both mileage AND aerobic intensity. So you need rest for both jogging and interval training. I can't say that one generally requires more, you'd just have to figure out that by observing your training.
Keep on jogging. It is the best way to lose weight. But remember: if you are running and replenishing your carb storage afterwards, your running is not making you lose weight, it's only keeping you from gaining more weight. You need to burn all of your carb storage so that the first thing you're burning in your workouts is fat. You may find that if you burn a couple of pounds of fat after one day, you can tell me I'm wrong. But you burn that fat while doing everyday things, after your carb depleting workout. So running plus low carb intake equals very powerful weight loss.

Hope this helps, the best of luck.
Jared

---------- FOLLOW-UP ----------

QUESTION: hi! thank you for replying me with such an extensive and detailed answer! thanks, now i'm doing HIIT from now on, I started today i didn't have a routine so i was planning on doing the one shown on wikipedia, wich consist of warm up jog then 60 secs of 5-6 jog and then 30 secs of sprint at 8-9 for 6-8 cycles. I was planning to do that at first but i ended up doing the sprint and walking for 60 secs instead of jog 5-6. I knew it was going to be hard at first but not this hard!,i'm willing to push myself but i guess i should start with a much easier routine maybe? could you please set up a good HIIT routine for a beginner thanks!

Answer
Okay, I guess if you really want to....
For intervals, you really need to figure out what type of session works for you. I can give you a general body, and let you put in the numbers and distances based on what you can and can't do. But remember, if it's High intensity intervals, you had better expect to feel like you can't run another step throughout the whole workout, and you're going to need a hell of alot of determination to complete a workout. But that's just the point. That is just what intervals are. They're hard.
I'll give you a couple workout ideas, but you need to be creative and make your own. The idea is to sprint as much as you can and have minimum rest time between repetitions.

My favorite is the x reps to complete 1 mile. You can do 400 meters 4 times, to have a total distance of a mile, and reps of 400 meters, well, that's a long way to sprint. So you want your recovery time to not be over 60 seconds.
Or you can take them 100 meters at a time, and have 16 reps. You are running short reps, so then your rest time needs to be equally short. Not more than 30 seconds.

If you want, you can run for 10 minutes straight, and have the first 30 seconds a sprint, and then jog for 60 seconds... then another 30 second sprint, then another minute of jogging. And do that for x amount of minutes. Remember, the less running time, the greater the intensity of your running time needs to be.

So be flexible, and have fun with the numbers. Hope this helps.
Jared