I decided I wanted to try working out with resistance bands. I'm new to this, so I bought these bands which were highly rated. I then found this video from the British Heart Foundation that teaches you how to do a basic workout with resistance bands.

I tried the very first exercise, shown below. You're supposed to raise your hands up to shoulder height, keeping your elbows slightly bent. The problem is that even the lightest band won't stretch enough to allow me to move my hands more than a couple of inches away from my hips. I don't think the problem is that I'm not strong enough; I think the band is simply too short. Even if I somehow managed to stretch the band enough to get my hands up to shoulder height, the band would be under so much tension that I doubt my hands could hold onto the ends. Unless these bands stretch a LOT with use, and I just need to keep trying?

Assuming I'm right and I need to buy different bands to do this type of exercise, what do I look for? Is there some terminology I need to look for in the product listing? A brand/model recommendation would be welcome.

That's not me in the picture, by the way. I wish I were that young and fit!