Heart Rate and Fat Burn

[Scotty.]

I ride a bike at the gym, and on the console it has a list that gives target heart rates by age for fat burn and for cardio. The fat burn is listed as 140 bpm (low intensity) and the cardio is listed as 160 bpm (high intensity) for a 20 year old.

Even at a relatively easy pace and resistance level, my heart rate gets in the 160+ range due to the ephedrine I'm taking. I would guess without it, it would still be 150+ because I'm kind of out of shape. I don't really fatigue at all, and don't get short of breath at the rate I'm going, but my heart sure gets pumping. Would it actually be more effective fat burning if I had my heart rate lower? To go much slower/easier would almost feel as if I'm doing nothing.

[SuitedSixes]

There was a thread in OOT that answered this question, but I don't remember which one it was. Basically, if you are in the "fat burning" zone, more of the calories you are burning are from fat reserves, however when you are in the "cardio zone" you are burning more overall calories from both fat and carbohydrate stores. So the answer to your question is "no" don't slow down.

[Wu36]

From wiki:
High-intensity interval training (HIIT) is an exercise strategy that is intended to improve performance with short training sessions.

A HIIT session involves a warmup period, several short, maximum-intensity efforts separated by moderate recovery intervals, and a cooldown period. The period of alternating effort and recovery intervals typically lasts a total of 15 minutes.

Studies by Tabata [1], Tremblay, and others have shown this method to be more effective at burning fat and maintaining, or building, muscle mass than high-volume, lower intensity aerobic work-outs. According to a study by King [2] , HIIT increases the RMR (resting metabolic rate) for the following 24 hours, and may improve VO2 max. Traditionally, long aerobic workouts have been promoted as the best method to reduce fat, as fatty acid utilization usually occurs after at least 30 minutes of training. HIIT is somewhat counter intuitive in this regard, but has nonetheless been shown to burn fat more effectively. There may be a number of factors that contribute to this, including an increase in RMR, and possibly other physiological effects.

cliffnotes: sprinting and other such high intensity work burns more fat than low intensity/high duration cardio through longer lasting effects on your metabolic rate.

if your primary goal is fat loss googling HIIT would be to your benefit. there are related concepts that don't involve sprinting as well
Tabata:
http://www.t-nation.com/findArticle....4-046-training
There was an avant labs article titled "iron cardio" as well, but since its from when I still read avant, im having trouble finding it. Basically just lots and lots of power cleans in place of sprints.

[skunkworks]

I think the idea of the "fat burning zone" has been debunked, but I'll have to do a bit more reading to confirm.

[kerowo]

I think something to keep in mind is that usually the folks who are asking this aren't in very good shape so there may be some advantage to training their bodies to be able to do something for more than 20 minutes at max effort. Nothing hurts motivation more than killing yourself the first day and not being able to walk for 3 days. If you can do the HIIT great, but don't think the only way to get any benefit from cardio is to do that.

[Scotty.]

[ QUOTE ]
I think something to keep in mind is that usually the folks who are asking this aren't in very good shape so there may be some advantage to training their bodies to be able to do something for more than 20 minutes at max effort. Nothing hurts motivation more than killing yourself the first day and not being able to walk for 3 days. If you can do the HIIT great, but don't think the only way to get any benefit from cardio is to do that.

[/ QUOTE ]

That shouldn't be an issue for me. I'm not in terrible shape, and I'm very motivated at the moment. I was on the bike for 50 mins the other day with my HR between 150-170, and I could have kept going for quite a while longer. I'm just trying to find the most effective way to budget my time/effort.

[kyleb]

[ QUOTE ]
I think the idea of the "fat burning zone" has been debunked, but I'll have to do a bit more reading to confirm.

[/ QUOTE ]

I'm pretty sure it's not debunked totally, but what SuitedSixes said is correct: Yes, low intensity cardio will burn mainly adipose tissue and high intensity cardio will burn some muscle, high intensity cardio burns fat/glycogen stores at a very high rate and the muscle loss is minimal at best.

[SmileyEH]

[ QUOTE ]
I think the idea of the "fat burning zone" has been debunked, but I'll have to do a bit more reading to confirm.

[/ QUOTE ]

Haha I wish. Half of the eliptical/treadmill/bike users have books with them at my gym. It will be a cold day in hell before grocery store fitness magazines start reccommending workouts that make you feel like vomitting afterward.

[Troll_Inc]

[ QUOTE ]

That shouldn't be an issue for me. I'm not in terrible shape, and I'm very motivated at the moment. I was on the bike for 50 mins the other day with my HR between 150-170, and I could have kept going for quite a while longer. I'm just trying to find the most effective way to budget my time/effort.

[/ QUOTE ]

I'm not sure what your goal is here, just weight loss, feel better both physically and better self esteem, look better to pick up chicks?

Generally, I would recommend a mix of workouts, which helps accomplish a lot of things.

1. The best way to burn fat is to exercise at your ventilatory threshold. Once a week add 10 minutes to your longest workout. But pedal at a rate just where you would start to breathe hard enough so that you couldn't carry on a conversation without breathing heavily. Without a doubt this is the range that burns the largest % of fat only.

As you increase effort you will start to burn more carbs and if you go too hard you will even shut down fat burning.

2. Do some of the harder workouts, throw in some intervals. Ride for about 10-15 minutes at a nice pace, then do some 3x3 minute harder efforts. The rest interval should be enough to catch your breath. For a warmdown do like 10-15 minutes again.

3. The absolute best workout to train all systems would be a warmup, then do short all out efforts for 30 seconds or so. Work up to 10-15 of these. Warmup and warmdown is very important.

If you just workout 3 times a week, then do one of the workout #1. Do this on the weekend.

Workout #2 and #3 - could do these on Tue/Thursday.

A world class athlete never does more than 3 hard workouts a week, so 2 is good for you. If you want to do more, then add in some easy 30 minute sessions.

Other
*every 4th week, just do easy workouts. Maybe a scaled down workout #3.

*for your easy workouts and the long/aerobic workouts work towards doing them on nothing but water..no calories before hand. A top cyclist in the winter will do long training rides on water alone. Once your body is trained enough to burn fat efficiently, this is the absolute best way to burn fat.

[Truja]

I'm not sure which is more effective at burning fats, but truth is that if I i train HIIT the following day I'm not feeling strong enough to train.