I need a back pack for this summer...to take to the fitness spa..to carry from exercise class to class. Not TOO big, and also keep in mind I will have on workout clothes the entire I time I use the bag...ANY IDEAS??? The Lv one looks a but too small?? I have the messanger bag but I do not think that will be comfy. Gucci? Fendi? I have not carried a back back in years. Maybe I would prefer a tote instead? I just need it casual...thank you for your ideas as always.