I am a 31 year old woman from Germany. I am already in good shape but I would like to improve my body composition a little (gaining lean body mass without gaining weight in general. I am weight-training 2-3 times/week, doing 8-10 reps/3 series. I would like to foucs on lunges as a primary leg-exercise but I have the following problem: When I use a barbell I cannot use the weight I need to challenge my legs properly for I cannot balance a bar that heavy on my shouldes and with dumbbells the problem is even more pronounced for I cannot hold an adequate weight in my hands. Is there another way to use lunges as an muscle building exercise without balancing so much weighton the shoulders/in my hands? I mean I could increase the number of repititions but that wouldn`t help in gaining some muscle...Is it reasonable to put the leg that is behind on a step for I feel that increases the intensity! Thank you!