I have owned Nicole Ari Parker's 'Save Your Do' gym wrap for almost two years and do you know not once have I used it with my hair straightened?! I think it's mostly because after I drop $75 on a press n curl (the going rate in LA btw) I don't want to take a chance on 'sweating it out' - who cares about me looking a mess, I'm gonna be more sad about the money I lost! In any case my friend Brocollete had more than enough nice things to say about the wrap and I actually think it worked pretty well for her. After enduring a level 2/3 yoga class in a 80 degree heated room, her press post-workout looked a lot better than I would of thought.
Cue two years later I try to do the same thing as my dear friend and I thought my results were not as great and for understandable reasons.
As you can see my hair does not hold a press well to begin with (only 4 days old!) and I don't even live in a humid state! It's frustrating, I know, which is why I don't press my hair often and that can influence how well you hair can take a press (we are talking about some dry 4b hair strands here). In any case, the 'Save your do' gym wrap didn't totally sweat out my hair but my hair definitely was in the process of reverting back to its original state. I figure if I went to work 1-2 more times it would of been 4b tendrils in the front with straight hair coming out the back which equals mess.
Although the gym wrap never guarantees your hair to stay straight anyway, if you just spent money to get your hair did and your hair doesn't hold presses well, I would not rely on the gym wrap. I think my friend had better luck than I did because of her hair texture and frequency of presses. If you fall in that category I would definitely give it a try - its inexpensive and part of the proceeds goes to a good cause!