Last week your challenge was to time yourself and see how fast you could do this workout. It's a pretty fun, quick workout you can periodically test yourself with. How did you do?   The best I could do was 7:17 with 35 pound weights. My goal is to get under 7 minutes next time.  
Your challenge for this week is use snowball goal setting. By this time many people have already given up on their New Year's Resolutions. This is your opportunity to start over fresh.
What's a snowball goal anyway? I've learned about this theory of goal setting from a few different sources. Most recently from a fitness professional named Alwyn Cosgrove. Not only is he one of the smartest guys in the fitness industry, he is Scottish so it is like James Bond giving you great information.
Here is snowball goal setting in a nut shell.
1) List five or six behaviors you need to improve or change to reach your goals. What do you need to be doing that you're not doing? What bad habits do you need to kick? What good habits do you need to instill?
2) List these things from easiest to hardest.
3) "Maintain" all your other goals and focus your attention on the first thing on your list (the easiest one.) Spend two weeks just focusing on achieving that goal so that it becomes a habit.
4) Once that change has been made and ingrained, move up to the next item on your list and focus your efforts there.
5) One by one, knock out these changes and/or goals.
For example: Maybe you sleep late. First goal might be to get up 15 minutes earlier every day.
Second goal might be to go to the gym as soon as you wake up - and go four times a week instead of three.
Third goal- make sure you always eat breakfast.
Fourth goal- reduce portion sizes at 3 out of 5 meals/snacks.
So in 10 weeks or so - you're getting up earlier - never missing a workout, got in an extra ten workouts, and eaten breakfast everyday while consuming less calories overall. These goals would "snowball" into a bigger overall effect with long-term success whereas trying to do all things at once would likely result in short term failure.
The main challenge overall is to keep going! Take some of the things we have done (food journals, not sitting too much, drinking plenty of water, etc...) and make them a part of your life.
Don't give up now!