In most fitness circles, there are two main “types” of cardio that tends to get discussed. The first is LSD (Long Slow Distance) – an example of which would be jogging. The next is HIIT (High Intensity Interval Training) – an example of which would be sprinting.
For various reasons, HIIT is generally considered a better form of cardio than LSD. This is because it doesn’t take as long to perform as LSD, is more power-based, is generally easier on the body physically, contributes to both aerobic and anaerobic increases, and keeps the metabolism “jacked up” for several hours after your workout is over. However, if you short-change your HIIT, and don’t work hard, you’re getting the least productive cardio workout of all.
And while there is nothing “wrong” with LSD, it does take a long time to perform, can be very tough on the body physically due to sustained shock and “pounding” it has to go through, and while it’s great for aerobic endurance, it does virtually nothing for anaerobic capacity.
There are two alternative types of cardio workouts that I like to use. One is Density Conditioning. Simply put, choose a short distance (30-100 yards) and do as many reps as you can in a given timeframe. Sprint one way, walk or jog back, and repeat – rest only if it’s absolutely necessary. The goal is to get more reps in each workout. These aren’t going to be sprints per se, but hard runs – kind of like that 8 (or 9) intensity level, but you’ll be doing a lot more overall distance.
The other cardio workout is MFD – Medium Fast Distance. This is where you choose more of a medium distance compared to your LSD. For example, if LSD runs are 5-6 miles, choose 2.5-3.5 miles. Run the entire distance without stopping (just like LSD), but do at a fairly fast-paced clip. The best way would be to set a mile time that is pretty quick for you, and try to keep that pace the entire run.
Density Conditioning and MFD cardio workouts both combine elements of LSD and HIIT. Where LSD is long, yet slow, and HIIT is short, yet very hard, Density Conditioning and MFD are both medium-long, yet hard (as opposed to very hard with HIIT).
Either Density Conditioning or MFD can be good ways of keeping your conditioning good, without having to spend hours doing it, or worrying about burning out your nervous system.
Train Hard, Rest Hard, Play Hard.