Hi,
This is in answer to your two questions, the 1st being the soreness you have been experiencing. You didn't say how long you have been lifting or the amt of weight and reps! Yes your back may be bothering you do to standing, and it could also come from lifting, especially if you are not resting and letting the muscles repair themselves. This is why I only lift every other day! The amt of calories burned is also hard to say as it depends on whether you are lifting low reps or fast reps. If you just started lifting you will gain weight since muscle weighs more than fat! I gained 10 lbs when I started back up! When I was younger I was a body builder, but now I just strength train! To get an idea of where you are, purchase a scale that has more than just weight readings, I have one that does my BMI, my water intake, my body fat content etc. This will keep you on track! I use this weekly on the same day around the same time, it's a ritual! Once a month a chart my measurements for change, and I build my routine from these results of my hard work! Hope this helps
I hit submit by accident, i had another question.
Is there a baseline for how many calories a person burns while weight lifting medium to heavy weight. It seems like the amount varies depending on who you ask or what u read