An intense set of lifting weights will elevate the heart rate. Though the set may last 10-30 seconds, this is all that is necessary to force the cardiovascular system to make adaptations.
The longer an intense strength training set, the more the cardiovascular system must work. After a set of 20 reps with heavy weight in a compound lower body movement, your heart will be pounding. Twenty reps of triceps kickbacks or dumbbell curls will not do much for heart rate. However, 20 reps of a heavy full range squat, deadlift, push-up or chin-up will drive up heart rate to supply these multiple large muscle groups with lots of oxygen.
Strength training indeed produces an aerobic training effect, even though this type of exercise is called “anaerobic”. One must lift intensely with compound (multi-joint) exercises to get the cardio effect just described. Nevertheless, strength training does not replace cardiovascular exercise, so you should always have cardio workouts as a consistent part of your regimen.Resource: OnFitness Magazine