There's a difference between looking big or "bulky" and being strong. Although it's true that the bigger you are, the more weight you can lift - including everyday objects like grocery bags - you can be stronger than someone who is bigger than you are. Each person can get stronger than they are already, and that includes you!
How do you do that? By lifting heavy weights, and by heavy, I mean heavy for you yourself. The amount of weight you need to lift to stimulate your muscles to grow bigger and stronger is probably a lot more than you think. Lifting that weight slowly with control for about a minute straight will make you stronger and your muscles bigger. As we age, our muscles get smaller if we are not stimulating them to either maintain their size, or grow bigger. The main difference in appearance between a young person and an older person is muscle mass. You can even see it in someone's forearms! A younger woman's forearms are more muscular than an older woman's who isn't exercising. You can see it in the shoulders, the arms, the legs, even the neck! More muscle doesn't mean you'll look like the picture above. You'd need to take a lot of steroids to get big and bulky, and even then, you'd need very unique genetics. For most of us, lifting heavy weights means we'll look more like we did or should have as a young healthy, physically active person. Nice muscle tone and posture, with an ease and energy in our movements.
A simple test you can do in order to determine how much you should lift, would be to take a weight light enough so that you felt you could lift it about 10 times. Now, chose a weight that is heavier than that (we are all usually already a lot stronger than we think :), then start to lift it slowly as discussed in the previous two blog posts. Keep moving the weight back and forth without stopping until you can't move it any more (called going to technical failure - read about it here). If it takes you about a minute to do (6-10 repetitions) then it is the right weight for you. Do the same with any set of exercises you like. Do this one time for each exercise you choose (it should be challenging, so if you're doing it correctly, you won't want to do any more!), write down what you were able to do. I guarantee that if you do it right, after a couple days rest, if you go back and do the same thing, you'll be able to lift the same weight for more repetitions or for a longer time. You'll have proven to yourself that you are stronger! It might take a couple of times to chose the perfect weight for you, but you'll get it. Why not give it a try?