Is conditioning necessary? In my opinion, definitely. There are many benefits to performing some type of conditioning, but the fact remains that most lifters will not do any cardiovascular work. I believe that this is due largely to the many myths which remain popular despite the evidence to the contrary. Many would be quick to point out that aerobics cause you to lose muscle or lose strength, but I have found this to be false in my own training and the training I have done with others. We run three times a week in the off season to prepare for football, and we lift twice a week. Despite the conditioning and speed work, everyone gained strength consistently at every workout. Another common myth is that for a positive effect on the cardiovascular system you must exercise with a low intensity for 20-40 minutes. I completely disagree, and I feel that a very high level of conditioning can be accomplished in 5-15 minutes assuming that the intensity of effort is high. I don't see the point in exercising with a low intensity; the point of training is to provide a stimulus for change, which will not occur to any significant degree if you are working below your capacity. The final myth is that aerobics, and running in particular, is dangerous. It is my observation that most people who incur injuries from running are usually overweight, out of shape, or obsessive (the stick people who run 5 miles every morning). It should also be noted that these people are jogging for long distances, which I do not recommend because of the lack of intensity.
I would recommend doing conditioning two or three days a week after a workout. All conditioning exercises are meant to be performed all out. Due to the extreme effort, the total volume is low. However, you can expect to be very exhausted, or possibly even sick, from doing these. It is actually not far removed from a quality strength training workout!
Here are some typical workouts that I would do to increase my conditioning...
3 300m sprints with 60 seconds rest between
3 100m sprints with 30 seconds rest between
5 gasers (sprint up and back the width of a football field twice) with 30 seconds rest between
3 full field suicides (sprint from the goal line to the 20 and back, to the 40 and back, to the 60 and back, to the 80 and back, and to the opposite goal line and back) with 60 seconds between
3 100m truck pulls with 60 seconds between
farmers walk for time
Rowing machine: all out for five minutes
Versaclimber: all out for five minutes
This type of training can be extremely beneficial. You will find that getting through an HIT session alive will be much easier (especially if it includes some kind of high rep squat or deadlift). You will also have a stronger cardiovascular system, which will translate to improved health. Also, if you are an athlete, the benefits of this type of training are obvious. Strength training is the best form of exercise, but it is not the complete form of exercise. Don't make the mistake of ignoring cardiovascular conditioning.
