There are a few levels of gyms in Hanoi.
Level 1: You have your basic, dirt cheap Vietnamese gym. These places resemble American prison gyms but not nearly as nice. These gyms cost about $10 a month to join and are usually open from 5-7 AM and 3-9 PM. These gyms usually have ten shirtless dudes standing around every free weight, waiting for their turn to lift it for thirty seconds.
Level 2: Hotel gyms. There are many hotels that offer gym memberships. The problems with these gyms is twofold: 1) They're expensive 2) You have to go to a hotel to work out. There aren't too many hotel gyms I've been to in my life that make me shout out, "This gym is awesome!" Certainly there are none that I've been to that are worth paying over $100 a month for.
Level 3: The recently opened super nice gym in Vincom Tower. This gym has everything including a lap pool and a $200 a month price tag.
After scouting out a whole bunch of gyms, I finally found a "western style" gym called Actilife. I joined for the year for about $400. The price is pretty low because I joined for off-peak hours which means I have to work out before 2pm every day. The gym has been pretty good so far but there have been a few reminders that I'm still at a Vietnamese gym:
Reminder 1: The other morning a guy was smoking a cigarette in the locker room. In defense of the gym, there is a no smoking policy in the gym. In defense of the guy smoking, he's Vietnamese so he thinks he can smoke anywhere.
Reminder 2: There was a guy running on the treadmill completely shirtless. Men love being shirtless in Vietnam. Eventually I'll have a post about guys who take their shirts off at bia hoi restaurants. It's always one of my favorite things.
Reminder 3: The other morning I showed up at 7AM and all the lights were off. I thought I had come too early but actually the power was just out. I asked the staff when it would come back on and they told me 3pm. I worked out by candle light.