So, I probably have done everything under the sun when it comes to cardiovascular activity:  jogged/walked, cadio-kickboxed, high-intensity stepped, sprinted, stair-climbed (all for countless hours at a time)--you name it, I've done it.  This includes gut-wrenching hours on the pavement of the streets of Greensboro, pounding out what seemed like endless miles.  And for what?  Okay, so there is that fact that I can say I've completed a marathon and 3 half marathons; BUT, aside from that, it didn't grant me anything other than dreadful, BORING, pretty much useless time wasted.  You go into these "things" thinking, "I'm going to get fit and look great and I'm going to do by way of (fill in the blank)."  Let's make this clear and simple:  More is NOT better!  I can tell you this from experience. 
You already know that I did the whole "I'm-gonna-lose-weight-by-going-vegan" thing, remember?  Well, at the same point in my life I decided to make another ridiculous decision and that was to start training for lengthy races--my first being a half marathon.  Long story short, not only was I depriving my body of much-needed nutrients that even a sedentary person would need to remain in okay health, but I was doing this while putting my body through hours of undue and unjust stress without giving it what it needed to operate at it's peak or to fully recover from all of that running.  I was literally breaking myself down on the inside and not seeing a damn bit of difference on the outside other than I started to look more "soft" than I did before I made those two not-well-thought-out (or well-educated) choices.
Long before this time in my life, back when I first got the initiative to start trying to lose weight, I definitely fell into the trap that I needed to not only eat less but MOVE MORE to get results.  Picture me:  NCSU student gym; 30 minutes on the elliptical, 30 minutes on the bike, 30 minutes on the treadmill; 1-hour long aerobic group exercise class; 15 minute abdominal group exercise class.  YUP, that's all in one day folks!  It's that MORE IS BETTER frame of mind we've all been conditioned to at some point.  Yes, I'll admit I got results initially.  This statement is analogous with any trendy diet:  You'll lose weight initially because you've either got excess to lose or your body has to take time to adapt to whatever it is you're doing that's different--or in some cases, BOTH.  But then what happens?  It all comes to a screeching halt.  You're left asking yourself, "But I've done (fill in the blank) for umpteen hours EVERYDAY and the scale is not moving!  What is going on here?" 
We've all been there if you're like me and have tried to lose weight before.  Well, frankly it's taken me quite a while to break down the conventional-thinking wall that we need to spend several hours a week stomping it out on a treadmill or going 500 miles on a bike the whole time you're at the gym.  A huge factor that feeds into the dread of doing these activities has nothing to do with the time spent doing it--it's WHAT YOU'RE DOING!  Simply put, if you don't like the activity, you're not going to want to do it, and you're not going to feel good while you're doing it, AND you'll dread the next time you'll "have to" do it before you even finish the time you're spending while doing it!  So ask yourself why spend so much time doing something that you HATE (I prefer the term LOATHE!) when you're really not benefitting physically or psychologically.
What really pisses me off is that the notion that we need to eat less and move more is still all that's being touted through the media!  Now, don't get me wrong--this principal definately applies to the woman whose currently trying to become the world's fattest woman (a soapbox subject on its own for me), with her weighing 1500 and some odd pounds by eating 20,000 calories a day.  Unfortunately she's near her goal, so maybe that's what matters?  But anyway, I digress!  Back to the notion of eating less and moving more for optimal health.
Eating less we can get into on a later date.  Moving more, I've already briefly touched on that.  Moving is good, really good.  Finding something you enjoy doing that incorporates lots of moving is even better.  Sports of any kind, for example, are a great choice especially if it involves a lot of full-body movement and gets the heart rate up for a period of time.  Here's where it's sticky from a "fun" stand point:  Though you need to find movement you enjoy, you should also incorporate other movements that truthfully suck while you're doing them BUT are over quickly and make you feel energized when you're done.  "What are you speaking of, some sort of torture is what it sounds like?"  I know this is what you're thinking and some people, including myself at times, could equate these types of activities with torture!  I'm talking about fast, quick, ass-busting (not literally, just figuratively!) sprints--whether in the form of running out or inside, biking, cycling, ellipticaling (I just made up a word).  Whatever the equipment, even if it just you, your own body, and a hill, move your weight from one point to another as fast as you can.........and then rest.  Rest only as long as necessary to move your weight again from one point to another as fast as you can.........and rest again.  Easy enough, right?  This is the type of "cardio" our ancestors did when sprinting to either run after their dinner or run in an effort to not become dinner!  What this means is that this is how our genes were made to perform:  short, intense bursts with periods of rest.  What this also means is that (given that you're working at optimal intensity) your "cardio" sessions could be cut down to as little as 15 minutes!  Starting to sound maybe a little less like torture, right?
I find it quite refreshing to start and end a cardio workout within 20 minutes or so--sure does beat those hour-and-some-odd-minute long bouts.  YES IT SUCKS while I'm busting my arse at 10.0 mph intervals on the treadmill; BUT, not only do I get rest between those sprints, my body welcomes the challenge and thanks me by BURNING FAT for fuel after I'm done!  Not sure about you, but I love reaping that benefit.  I can honestly say that since the lightbulb went on for me in regards to how to do cardio, I have been in the best cardiovascular shape of my life and have never been so lean (and MEAN some would say!).  It's definitely worth the challenge; it sucks, but you're done in 20!  Can't argue with that!