I'm 45 and am working on losing body fat. Part of my program is to lift weights (free weights) three times a week. The reason I'm lifting weights is because 1) I know that muscle burns more calories than fat, so I want to build more muscle tissue, and 2) I want to have a little more strength for sports and everyday activities.

Currently, I do three sets of 12 reps each, things like lateral raises, one-arm dumbell row, bench press, triceps extension, biceps curls, leg lift, etc. Usually, I'm struggling to finish the last two to four reps of the last set.

Should I increase the weight a little and do three sets of 12, then 10, then 8 reps? Should I be struggling to complete the last few reps of each set?

Keep in mind--I'm not looking to be a body builder or to compete or to even be ripped or sculpted or whatever. I just want to burn more calories, so I want more muscle.

Thanks!

Whether you are doing 12, 10 or 8 reps, the last rep should be to the point where you cannot perform one more rep or close to that. Any of those rep ranges will work fine for you.

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+1 The important thing is that you are working your muscles till they can't work no more. Once your body begins to adapt to your workout, then its time to change up the rep ranges.

that, or change exercises, or add some weight.