Lift weights after or before your cardio ?
If your goal is to build muscle, do cardio first. A study looking at the hormonal response to doing cardio before or after weights found that in men, anabolic hormones like testosterone remained elevated longer when weight lifting was done after cardio. theres is some evidence that this applies to women as well.
If you are looking to build endurance more than muscle mass, consider doing the opposite. another study looked at the different genes and signaling pathways that were activated by switching the order of weights and cardio. Essentially the final type of exercise you end your workout session with has a greater adaptive effect. Doing cardio last suppressed anabolic effect of weight lifting to some extend and it increased protein breakdown more doing weights last allowed those pathways involved in protein synthesis and muscle growth to remain active.
Source: Muscle & Fitness Hers Magazine