Instruction: Given the user's review, identify the user's sentiment from the listed options. Answer using one of the options.

Input:
I've had it on and off for almost 15 years. For me, when it starts, it sticks around for months.

I read about the studies that demonstrated how much faster people get better with this bar and a simple exercise. To be brief, the had to cancel the studies early for ethical reasons: the FlexBar group was doing so much better than the control group that they couldn't, in good conscience, allow the control group to continue without the FlexBar treatment.

I can attest that this gets you to a place of very little pain very quickly. I've been at it about 2 weeks and I now only notice it when I stress it badly.

I read some reviews on some of the other FlexBar offerings on Amazon, where people bought a resistance that wasn't right for them and regretted it. After reading and thinking about it, I decided to get red(light), green(medium), and blue(heavy). I lift weights, worked construction for a couple decades, and am just generally a little stronger than the average guy. Some others might do better with yellow/red/green(yellow being extra light).

I found that the red was pretty much uselessly light for me, and spent a week on green with very rapid improvement, then went up to blue.

Another interesting thing -- I have plantar fasciitis, and I bought a wooden foot roller thing, which is kinda nice, but the little booklet that comes with these also recommends them for that, and I tried it, and it is WAY better that the wooden one. The difference seems to be that the ridges on the FlexBar run longways down the bar, whereas the ridges on the wooden thing are circumferential. So, when you roll your feet across it, the wooden ridges are going parallel to your motion, while the ridges on the FlexBar are cross-wise, and that seems to do better about stretching and massaging the tendons.

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: A: very positive