This is the routine I use for me and my girlfriend when we go to the gym. It was designed around my specific needs, but is a good general workout that I think is worth trying. Not geared specifically towards anything, but will help condition the entire body for whatever activities you do, like DG.
The emphasis is on the upper body because I'm a skateboarder and like to keep my legs fresh for that. On days when I know I'll be skating a lot I skip the leg exercises except for leg curl, since that muscle isn't really used for skating. You'll notice repeated back, chest and ab exercises. Those are my strongest muscle groups and I find I have to hit them really hard to make them grow.
I am not a believer in multiple sets or high reps. I've lifted for about 6 years now and I've experimented with many styles, and I just didn't find either to be effective for me.
1. Leg Press
2. Calf Raise
3. Leg Curl
4. Leg Extension
5. Chest Press
7. Pec Fly
10. Tricep Pressdown
11. Reverse Curl
12. Lateral Raise
13. Reverse Fly
14. Ab machine
16. Weighted situps on decline bench
18. Glute Extension
19. Side Bend
20. Short walk outside
I would recommend only one set per exercise and aim for 8-10 reps. If you can do 10, then you need to increase the weight. If you can have a friend help you out with some forced reps at the end that can help too if you're looking to hit certain muscles really hard. Those last few extra reps make a big difference.
The goal of this routine is to effectively workout your entire body in a short amount of time, and stimulate muscular growth in an efficient manner.
For my body I've found that taking the heaviest weight I can manage to actually rep and working with it is key. I do not feel 50% weight warm-up sets are a good idea, or 80% sets followed by a "maxing out" set. Essentially I feel you should always be "maxing out" in the sense that you're using the most weight you can and not hurt yourself or only manage 2 or 3 reps. If you can only get 5 reps of a given weight, that's fine, stay with it and aim for 6 next time. If I do curls with 60lb dumbbells for 6 reps I find my biceps worked better than curling 50lbs for 10 reps. Takes less time too. If you train this way you shouldn't even want to do multiple sets, because you worked as hard as you possibly can at the first set so the work for that muscle group is complete already.
Always use good form. For example, never move your back when doing curls, and don't slack on the negatives. Control every movement of the machine / dumbell when you lift, NEVER, EVER let the momentum of the weight drive movement, ONLY your body. Use less weight if you have to, but this is essential to keeping yourself from getting injured and getting the most out of every lift. If you jerk with your back and heave the weight and let momentum carry it, you're cheating yourself.
If you move quickly between exercises it will benefit your cardio. Using heavy weight and using short rests will make you breathe heavy pretty quick. You won't need "cardio" days, this will be your cardio. The exercises are ordered so that you should be able to get up from one machine and move directly to the next, pausing for a few seconds to drink water and wipe off sweat as needed. Sit and rest for a minute or two if you feel short of breath, dizzy etc., otherwise try to move quick.
Really this routine is kind of overkill in certain areas, most people could probably do fine taking out a chest, back and ab exercise. Another good idea is mixing up exercises, like doing reverse wrist curls instead of reverse curls one day.
You should do this workout 2 or 3 times per week. You should always rest a minimum of 72 hours between workouts. If you do this workout more than 3 times a week you will definitely be over-training, no matter what condition you're in.