Same difference. You're not going to build much strength lifting 5 lbs weights.
Lifting light weights and high reps will not get you any sort of significant gains in strength. It's endurance building. It will take you the next 5 years to move up in the same amount of strength you should be able to move up in 2 months of lifting heavy.
I'm 5'2 120 lbs and don't pick up a weight less than 40 lbs for rows, bench 100 lbs and deadlift close to 200 lbs and that's with only 3 months of heavy lifting/compound exercises. Lifting 5 lbs weights will get you nowhere fast. You likely lift grocery bags that weigh more than that.
If you are trying to build strength you need to lift a weight that is challenging and perform compound exercises in the 5-6 rep zone before moving up in weight. Not 15 reps with 5-10 lbs weights. Stop doing bicep curls, tricep extentions and whatever else you're doing and do bench press, overhead presses, rows and if you can... assisted pull ups. For lower body; squats, lunges, deadlifts.
Stop doing concentration exercises and do compound exercises in the 5-6 rep zone, move up in weight once you can do 8 reps and you will build strength quickly. I wasted 8 months of my life with pastal Barbie weights and it got me nowhere. 2-3 months of heavy lifting I went from benching 50 lbs and deadlifting 130 lbs and have had a 50 lbs increase on both my bench and deadlift.
What you are doing is endurance training (ie: cardio). Don't waste money on dumbells. You will have to pay every time you move up in strength which will wind up costing you more in the long run had you just invested in adjustable dumbbells and a barbell with plates.
4-8 reps = strength building
8-12 reps = mass building
12+ reps = endurance building (cardio)
If you're not interested in strength training then that's fine but what you are doing is cardio, not strength training.
Edited by: JENNILACEY at: 8/16/2013 (08:46)