Can't most of these benefits also be found with weight training?
Yes and no. "Exercise" is an all-encompassing term that could cover anything from walking a 20-minute mile to taking a yoga class to lifting a 300-pound front squat. It's absolutely true that exercise, in general, can provide some of the benefits discussed above. For example, using a combination of both weight training and cardio training has been shown in some research to promote better cardiovascular health than using only one method or the other. (23) However, weight training programs can require more specific attention to programming and progression than cardio. Manipulating weights, sets, and reps can be more challenging and can involve more planning than going for a walk or taking a bike ride. There are also some physical capacities that cannot be built without longer duration cardio exercise. Just ask any pro fighter who's ever gassed out in round four or any strength athlete who's needed an oxygen mask between lifting attempts. For the best overall improvements in your health, physique, and overall performance, find ways to follow a well-designed, goal-focused plan that incorporates resistance training and cardio exercise on a regular basis.