Heart rate question

[karate_chick]

I've just completed todays 30min interval training at the gym on the treadmill and used the integrated HR monitor at the end of the session. I was a little 'shocked' to see my HR was 171 which, according to their chart, meant I had gone way beyond the 'fat burning' zone & just beyond the 'cardio training' zone.

My question is this: If my primary goal is to burn fat, am I working too hard? Is this having a detrimental effect?

I'm 36, 5ft 4inc and weigh 56kg.

Please advise.

TIA
Andrea

 

[CathydsRNA]

No. If you are past your fat burning zone, you will be initially be using other fuel stores in addition to fat to supply energy during the workout but eventually those fuel stores are restored from fat stores and if you burn 3500 calories it will ultimately be losing 1lb of fat and so you should really be keeping track of calories if your desire is to burn fat. If you are wanting to keep your heart rate in a lower zone for another reason than slow down but for burning fat you are better in the higher zone becuase it uses more calories and as I said many will come from non-fat energy stores initially but these stores will be replenished from fat stores.

 

[Imafitnessfreak]

When your heart rate works above it's target zone, the body pulls glycogen for fuel, so during the actual activity you are burning sugar. HOWEVER, the after burn has you burning fat for up to 24 hours. This is why interval training is so popular...you work at a comfortable pace for a few minutes, then push really hard, so much that your heart rate is above it's target range of a minute or so, then slow it down for a few minutes, then shoot it back up again.

If you were to workout at a slower pace, say just below target, you would burn more fat DURING the activity but the lack of after burn makes this useless.