UFC Personal Trainer

There's an exploit you can use to add up to your workout time. I used it after the game glitched three times on me and reset my progress to zero (usually around the 25-29 hour mark, but fortunately I had a backup of my save).

1) Build a dummy by putting a towel over a small chair or any similar item (a stool or a box might work as well, just like for some other Kinect games) and put it just outside your playing area.
2) Start a custom workout with your favorite trainer (I chose Mark Dellagrotte, but I think any of them will do).
3) Select V Ups as the exercise (it shows up on the fifth page) and click Start. I don't think my trick works with any exercise besides the V Ups.
4) Do the minimum number of reps (which is 10 for Bronze, 15 for Silver and 20 (?) for Gold), By then, the countdown will stop and your trainer will expect you to do a few additional reps.
5) Pull the dummy in front of you without leaving the playing area. For best results, keep it close to the edge of the hexagon. Crouch behind the dummy and quickly move outside the playing area and hope the Kinect won't notice that you are gone. If the Kinect loses track of you, you will have to restart the same exercise.
6) Let the game run for some time (I didn't go past 45-60 minutes, but you might want to gamble for more time).
7) Come back in front of the Kinect and do the last few reps until the trainer tells you to stop.
8) Access your stats and make sure that the game registered your "progress" properly.

A word of warning: as I said before, my progress was reset to zero several times. So I would advise you to make backups to a USB key on a regular basis. I cannot imagine using that trick for a full 30 hours, but if you reach the 25 hour mark and are getting bored with the game, this might be something to consider.

The achievement explains itself. If you are going for the 100 days consecutive for a workout you need only 18 minutes a day. For those less physically fit like myself just try to put in a couple hit the mitts at the end of your workout. I find them good for cooling down and they add a minute and a half or more to your workout. Not a hard grind really just a long one.

Easy workouts like skipping or jumping jacks work good too if you have the endurance. Warm ups and cool downs eat up almost 10 minutes combined. Remember to keep an eye on your player tracker.