I would say this - weight training: don't use machines, become one. Use free weights. Squats, dead lifts, power cleans, press, etc. Big, powerful, and functional movements build strength, speed, and explosiveness very fast, but don't worry you wont become a power lifter unless you want to! Get some coaching if you are unsure how to properly execute such lifts. A quote I love from a coach, when asked why squat rather than leg press machine, "Comparing a squat to a leg press is like comparing a Belgian truffle to a piece of dog sh_t!"
For "cardio" ... I think you can do a lot better in the same amount of time or likely less. Interval training will do a lot more for you than a boring 30-45min run on a treadmill. Check out this link on HIIT interval training:
~ ~ ~ Body for Life HIIT Training Routine ~ ~ ~
I would caution you to not jump off the deep end if you give a HIIT session a try as they are very taxing if you're willing to put forth the effort. Here's an example of a HIIT session you can do on the life cycle or whatever indoor upright exercise bike your gym has. The recumbent style with feet out front aren't as well suited for this in my experience. Looking at the link above, you'll see how you increase resistance every minute on the minute over a four minute cycle. The goal is to increase work load over that time, so you keep the same cadence (pedal speed). The soccer mom with her book next to you may give you odd looks as you crush the pedals in the last minutes of each cycle. I usually set the resistance quite high so the last minute of each cycle requires me to stand up on the pedals.
Work harder and smarter for best results. Good luck,