Maybe I can't answer since I don't travel frequently, and that was a caveate to your question.

BUT, I tend to look for hotels that AT LEAST have a fitness center.  Most of them have a piece of crap stationary bike, but at least it's SOMETHING.

There is also a "find a pool" website that I have used on several occasions.  I'm sure someone will remember and post it.  Most gyms allow you to use the facilities for a day if you pretend to sign up or just want to check it out.  YMCA's usually have day passes, but can be expensive.

Lap pools:  http://www.swimmersguide.com/query/main1.cfm

Maybe look into YMCA membership if they are accessible in many of the cities you visit.

Spin classes are fine if that's what you have access to.  You can get a very good workout from them and they are close enough to 'real' cycling that it provides definite carry-over to your riding.  I prefer to use my own trainer and bike most of the time, but some find it much easier top 'push' themselves in a group setting.  That can be reason enough to include them in your training.  A short ride or run on your 'rest day' won't generally hurt either.

I don't travel much myself, so hopefully some others provide some more practical experience.

If you're going the YMCA route (which is a great idea) just be sure to check out the local Ys policies where you're traveling. I worked in a different state for a month once, and their YMCAs were super leery about letting me in more than 3x in the month or something like that. Even though I took all the necessary steps to get the "travel" membership card.

Other ideas are to pack some resistance bands/cords in your suitcase to get in a little bit of strength training in your hotel room - throw in some core stuff and yoga/stretching and it's a nice little workout.

To your question about spin classes producing fitness for the road--

I may be biased as a spin instructor, but I definitely find it easier to elevate my heart rate in class.  I find I burn more calories and feel more localized muscle soreness than I do riding outside.  

On the other hand, I don't think attempting to do a hill type workout on a spin bike correlates well to riding with elevation outside.  You also remove the challenges of balance, shifting, navigating.

In short, spinning could build just as good of a base of cardiovascular and muscular fitness as riding outside but shouldn't fully replace outdoor rides.  If you don't have road riding available to you, spinning can be an integral part of your triathlon training.  When home, train outside or at least on your bike on a trainer as much as possible.

I love spin class and go once or twice a week. I think it has a lot of value.

If you can't get to a class but have a stationary bike, I have a couple Sufferfest videos on my phone. That's really good for travelling. I also have some yoga workouts on there from yogadownload.com. Very easy to take with you.

I travel frequently for work.  Not as regular as your M-R schedule, but i traveled quite a bit and still "adequately" trained for IM this year.  I would do the bulk of your bikes when you're at home.  are you talking about a spin class while you're on the road?  That would be a good to throw in there every now and then.  I swim and run on the road.  Always find a lap pool and make sure you specify its 25 yds.  Find off the beaten path hotels that are by run trails etc.  I've had some of the best runs on trails away from home.  Makes for an interesting time going down memory lane when checking my garmin files at home.

In summation, I'd focus on run/swim while on the road.  Very doable as long as you're willing to put in the planning time on the front end.

I live between two cities and do not have two sets of equipment.

For cycling, if you can figure out some great workouts for yourself (hint: check out Jorge's cycling programs here on BT), honestly, you can get a great workout on a crappy plastic exercise bike. I do. Resistance goes a long way toward that.

For swimming, get some swim cords so you can swim no matter how big or small the pool is: I have Aquavee swim cords. They're expensive but if you can get 'em on discount, they're great. Really, anything similar that you can buy or build will work fine. Do NOT buy the kind that attach to your ankles or feet. They screw up your stroke.

If there's no pool at all, I get a *lot* of mileage out of my Halo dryland swim cords. I'm pretty sure there are videos on how to best use them at www.sheilat.com ... also a great set of swim-specific strength training exercises in Going Long by Friel & Byrn.

Heck, you can just air-swim with them.

Those look pretty slick and not too expensive if they work well. 

I don't travel as much as the OP but I've usually concentrated my run fitness, strength training (as available), and core work.

I've swum the living crap out of mine for over three years in every kind of pool (salt, chlorine, bromine, murky) and temperature imaginable in a few different countries and they are still going strong. I think there's a picture of me somewhere attached to a banana tree, going at it in a plunge pool ...

I travel a lot as well I was only home 2 days in July and 2 days in August and they were even 2 consecutive days! 

How much storage does the sufferfest videos take? How do u download them on the iPhone... I just found out about this the other day that is an AWESOME idea!

The Athletic-Minded Traveler - 2nd Edition  On sale now: http://www.trisports.com/attr2nded.html

dp

A little OT, but it strikes me that this thread is a great example of how useful BT can be.  Lots of good information here!

I travel for business throughout North America on average 10 days a month.  

For running I check on Google Earth to see if there are any trails near my hotel then use my Garmin to track distance.  This is the main reason that I have a Garmin, if I have a 6 mile run planned I just take a right outside of the hotel and turn around 3 miles later.  For swimming I usually don't swim on the road but every once and a while the hotel that I am staying at has a relationship with a health club that I can swim at.  For spinning most hotels have a spin bike in their fitness room.

Hiya,I also travel sometimes for work.

Some things that have helped me:

1. If appropriate, always mention to people in meetings/conferences that you are going for a run in the morning - you will be surprised how many people at a conference/meetings will also have packed a pair of running shoes and are also looking for motivation.  At one conference I ended up meeting a guy who was a cyclist, we joked that next time we are in the same conference venue we'd each bring our bike...3 months later I turn up to a big function at a beachside place to find he had arrived with is bike (but I didn't bring mine...) .

The other  good thing is if you tell people Wed night you are going to run 8miles that evening, when you turn up for breakfast/follow up meetings the next day they will ALWAYS ask how you went - so even if you can't find a running partner, its often motivation to know that you will need to have answers in the morning.  Also, I often find people who will say 'oh, there is a great running track down such-and-such road...'

2. ALWAYS pack your shoes, ipod, Garmin etc.  Not having equipment just leads to excuses for not training - if you have all the equipment, there is no excuse!

3. hotels/concierge desks sometimes have maps of running tracks/popular running paths. At one of my favourite hotels (Radisson Blu Sydney) when you return from a morning run, the doorman is ready with a cold bottle of water and a towel (I'm not kidding!, they have a little esky/ice box full of water for all the executives who run before meetings....)

4. One of the BIG challenges for me is watching my food. If I eat too much dairy it plays up my asthma and I find exercising difficult.  When on the road its always tempting to grab something at the airport or in the meeting that means I find it difficult to run later in the day, so I need to watch what I eat.

5. I have a PDF document of stretches and core exercises saved on my ipad - so even if I can't get in a decent run/swim when on the road, I can always find time for 20 mins of core work...

6. Going for a run is a great way of seeing a new city/place where you have never been before, and with google earth, the internet and forums, you can always find a decent run - so I always tell myself there are no excuses for not getting in some decent training 

7.  The other thing I tell myself - even a little bit is good.  Even if you tell yourself you only have time for a 2 mile run, its better than nothing.  And often, a 2 mile run becomes 5 or 7 quite easily.

 I have to look up how much space it takes. I don't put a ton of stuff on my phone so I haven't looked into it. I have 2 sufferfest videos on my phone now. It's very easy to download to phone. When you buy, they give you the file and you put that into your iTunes and then right to your phone or iPad or whatever.

I don't travel as much as the OP, and it's more sporadic.

Running is easy, of course: just take your gear, get up early and go. Since I end up seeing far more of the place than I would otherwise, I find that the running adds a lot to my trips.

Swimming: pools are typically unreliable and take a lot of time, so I take my StretchCordz and try to hook them up to something strong in the room. Far more time efficient. The best situation is if there's something bench-like in the room (for lying on), and a strong door handle or similar, but that's not always easy to come by. Very time efficient, though.

Cycling: I occasionally use a bike in the hotel gym, but rarely bother. Biking can tolerate bursty training more than running can, so I simply fit the training around the trips ... and make up for lost bike fitness when I have run injuries and end up doing a lot more biking. But taking Sunday off in addition to being away for much of the week makes it more challenging - I would be at a loss without the weekend time.