Hi Bunbun! I can't be objective here because massages are my life!

, I am a Registered Massage therapist. Given the options and considering that this is your introduction to massage, I would go for the Swedish massage. These are the classical soft tissue manipulations (kneading, scooping....), shiatsu works with slow, deep, specific compressions along the bodies energy meridians (most correspond with the paths of the nervous plexi). Sports massage would be more specific to your individual areas of concern with deeper work, use of ice or heat, passive range of motion and more work in the tendons of the muscles as opposed to the muscle bellies.
The therapist is trained to address your concerns and thoroughly answer your questions, they will come up with a treatment plan based upon your health history and a brief interview which may include orthopoedic testing to address any specific soft tissue concerns that you have. The massage should not proceed until you have given your informed consent for the proposed treatment planned. You might want to ask for a 'general full body' massage for the once over. If the therapist is doing ANYTHING that makes you uncomfortable in ANY way you need to tell them, this is your experience! If the pressure used causes you to hold or jam your breath or you feel your body holding on to tension as opposed to releasing tension it's completely appropriate for you to tell the therapist. Your body will be draped (covered in sheets) and the therapist will only undrape the part being worked on, you should not be exposed in anyway that makes you uncomfortable.
Response to touch is an individual thing as we all have different levels of comfort and various associations with it, massage is a wonderful and unique experience which brings with it increased body awareness and for most a feeling of physical lightness that can resonate for days and for some for weeks. I love my work and feel privileged to be able to provide so many with an oasis in their long and busy days. To have someone thank me for getting rid of their persistant headaches or help them recover from a car accident or a nasty fall more quickly gives great meaning to my life. I still get excited about receiving massages. I am getting one tomorrow evening and am already full of happy anticipation knowing how terrific I'll feel afterwards. I hope you take this opportunity and enjoy it to it's fullest. Don't close your mind if you don't love the first one, the first time I had deep gluteal and hip work done I cried like a baby, not because it was physically painful but because it was a profound emotional release. As a result of that experience I have paid close attention to stretching these muscles and not allowing emotional stress to physically manifest itself in that area. I could go on and on and on about massage ad nauseum, massage literally changed my life and I truly believe that the world would be a better place if more people made it a part of their life.
It wouldn't be right not to include a caveat, massage is not for everyone, you have to do what feels right for you at this point of your life.
Please let us know how it went if you do opt for the massage. You deserve to feel as good as massage will make you feel.
Oops, someone's at my door, pardon any grammar or spelling errors please!
Take Care
Laurie
