Hi everyone just a quickie I have been an avid exerciser for say 10 years eg spinning classes circuit training lots of cardio with a heart rate monitor.Anyway since atkins(4wks now)my heart rate is going to my normal point i train at between 150-175 doing a lot less.Has this happened to anyone else,do you know why and will it change back????? questions, questions i hope someone can help shine some light
thanks

burning glycogen is the most cardio friendly fuel, burning ffa (free fatty acids) is slower and "less efficient"

so if you are doing the same intensity as before, your body is working harder to supply oxygen to burn the ffa ( ie increased heart rate )

after awhile your body will better adapt to using ffa as a fuel, but lc is not ideal for maximal aerobic performance

which leaves you with some choices
1. accept this and change the way you excercise to lower intensity or use HIIT
2. insert some carbs into your diet
3. try a little less extreme low carb regime for your way of life

Don't forget that once you understand what m0rgan said that over time you can train your body to rely on useing a higher % of fat stores at a higher heart rate but that does take time.

Thanks for the advice but could you tell me what HIIT is ?

high intensity interval training

Spin,

I am having the same issue at the gym as well. Thought it was just me. Thanks for the reassuring answers CueBald and Morgan!