I spend summers in Canada to escape the heat. But problem is rest of the year gets very cold..and gloomy. U.S. is too big to generalize, you can have the highst end, most urban to most rural farm town. Problem with most of these suggestions is 1. Not as easy to obtain Visa 2. Currencies are high compared with Portugal. For personal trainng, how about Rio de Janeiro? You already speak the language and the people on the shores are obsessed with looking hot.

Asia in general is extremely difficult if you relied on English and next to impossible with Portueguese.

If you're becoming a professional with your degree, I wouldn't recommend Canada. They hire few international graduates, and they make most foreign graduates do an extra few years of extra studies to "upgrade" their degree to meet the Canadian requirements (not required if you obtained degree from the United States and the UK I think). Also the pay is little when you consider living costs.

Switzerland, you can sleep on my bed if you want too.

UK, Australia or Canada. Probably in that order.

Why would you rank UK as first? 

Ahhhh ha ha it's 95% barren desert and always will be. The driest continent on Earth. It's why despite being almost the same size as the USA it can only support a population 1/10th that of the USA.

Don't come to New Zealand, personal trainers get paid shit here. Actually everyone gets paid shit here, it's why so many people leave and go to Aussie. At least in Aussie you get paid well, so go there.

With your Portuguese accent and bronze body you'll have Aussie gyms falling over themselves to hire you to attract the female clientele. If you go to USA there will be thousands of bronze accented dudes being personal trainers to ladies working in gyms, so you'd be nothing special.

If you want to work with kids or the elderly you'll get paid shit wherever you go. But you'll get a lot of satisfaction out of life. And if you work with older people you'll meet some amazing individuals who have great stories to tell.

There's also this to consider, from a more objective source.

Best Infrastructure

Singapore
Frankfurt, Germany
Munich, Germany
Copenhagen, Denmark
Dusseldorf, Germany
Hong Kong
London, United Kingdom
Sydney, Australia
Vancouver, Canada (tied with Hamburg, Germany)

Best Quality of Living

Vienna, Austria
Zurich, Switzerland
Auckland, New Zealand
Munich, Germany
Vancouver, Canada
Dusseldorf, Germany
Frankfurt, Germany
Geneva, Switzerland
Copenhagen, Denmark
Bern, Switzerland

http://newsfeed.time.com/2012/12/05/the-worlds-best-and-worst-places-to-live/

The american economy is in the shitter, try somewhere else with good job oportunities for graduates. 

You will most likely have to travel with that degree anyways. 

Why ?

Anyway i would love to go to AUS and my dream is to work as PT or developing Kids at their young ages or even helping old people with the pshysics.

I can do others things though.

Why not? There's a lot of immigration here; giving the possiblility of work and a stable life. And its English. A language most people know.