Say I follow this running schedule here:

WEEKS #1, 2: 2 miles/day, 8:30 pace, M/W/F (6 miles/ week)
WEEK #3: No running. High risk of stress fractures
WEEK #4: 3 miles/day, M/W/F (9 miles/wk)
WEEKS #5, 6: 2/3/4/2 miles, M/Tu/Th/F (11 miles/wk)
WEEKS #7,8: 4/4/5/3 miles, M/Tu/Th/F (16 miles/ wk)
WEEK #9: same as #7,8 (16 miles/ wk)

By the end of week 9, I should have a pretty healthy cardio system. My question is, does the cardio vascular system get more effective or improve itself at all? The current theories are that above 80% of a person's MHR, that cardio becomes an anaerobic activity. Could my cardio system improve itself enough to where 80-90% of my MHR would become an aerobic system?

If that isn't how the cardiovascular system improves itself, then how does it? What allows you to run that extra distance when you train? Does your body just realize it needs to adapt for that specific distance?

To improve your aerobic fitness you need to work at a variety of heart-rates. While it can be effective to measure them during exercise, I would recommend not. A heart-rate that may be uncomfortable for you to run at one week may be comfortable by the next as your fitness improves.

To improve your aerobic fitness you need to do a variety of workouts - varying terrain, pace, and total time:


Run for a long time (45-60 minutes) at a comfortable pace on flat terrain. (Long distance endurance runs.)
Run for a long time at a comfortable pace on hilly terrain.



Run for a moderate time (15-35 minutes) at a slightly uncomfortable pace on flat terrain. (5k races, for example.)
Run for a moderate time at a slightly uncomfortable pace on hilly terrain. (This pace should make you really have to push it throughout.)

^ Pick a distance that you'll finish in between 15 and 35 minutes, 3.1 miles (aka a 5k) is a good distance. Time it and then try to beat this time every week.


Sprint short distance on flat terrain. (Sprinting is always at a very uncomfortable pace.)
Sprint short distance up hills.


Times are suggested but by no means should you start out doing these. Just keep all this in mind after you've reached a fair shape with your current plan and want to improve it.

Running longer and longer distances alone is not the best way to increase your aerobic fitness. You need to vary your speed and terrain to vary intensity.

Don't run on anything but grass or track if you can help it.

Never stretch before your workout and always warm-up by running for about ten minutes at a very easy pace. On "long time" runs you can do this and then quicken your pace and count it as part of your total time; stretch afterwards. On "moderate time" runs do this before your run, stretch, and then start your workout. On sprint workouts run for 10 minutes at an easy pace, stretch, do some build-up sprints (gradually get faster), stretch, then move into your sprint workout, and finish with an easy run (basically repeating your warm-up) before stretching. Always stretch thoroughly after your workout.

The current theories are that above 80% of a person's MHR, that cardio becomes an anaerobic activity. Could my cardio system improve itself enough to where 80-90% of my MHR would become an aerobic system?

Yes and no. You'll still be anerobic at 80%+, but what will happen is that as you improve, you will be able to perform more intense work at the SAME levels.
When I started working out in April, a 4mph walk would push my HR to 155. It only took a couple of weeks before that same routine only carried me to 125.

Today, a 4mph walk with no slope barely gets me to 110, and I can run 8mph for about 2 minutes before I have to slow down... this level of work brings my HR to about 160 or so.
In May, I couldn't maintain a 6mph run for more than 1 minute. Today, my cardio routine consists of a 5-minute interval plan, alternating 4mph with 6-7mph runs and an occasional 8mph blast.

Don't rely so heavily on a published schedule (I recognize the one you posted, but can't remember where I saw it... it reminds me of the BUDS program). Instead of using a pre-set schedule, try to work to a given HR range and push the intensity as your working HR drops. This may or may not allow you to match the schedule you posted.

One of the best ways to gauge your cardio effort and ensure that it remains aerobic, is to maintain a level low enough to where you CAN engage in a normal conversation, but high enough to where you really don't want to.

Yes and no. You'll still be anerobic at 80%+, but what will happen is that as you improve, you will be able to perform more intense work at the SAME levels.

That makes sense. Is there a roof to cardio fitness based on a person's age as MHR is? I'm sure at around 50, you can't exactly run a mile at a 6:00 pace, but I'm more concerned with the ages between 19-28.

(And yeah, that is the BUD/S workout. Congrats. Have a protein shake :D )

That makes sense. Is there a roof to cardio fitness based on a person's age as MHR is? I'm sure at around 50, you can't exactly run a mile at a 6:00 pace, but I'm more concerned with the ages between 19-28.

In actuality, no, there is no limit. It depends on your conditioning level, and probably on damage done due to lifestyle in earlier years.
The classic formula for max HR, for example, is to subtract your age from 220. Lance Armstrong has a resting HR of around 30 or less (Bjorn Borg was in this league), yet when required, he can crank it up and sustain a heart rate well in excess of 180.
President Bush is in very good condition as well. His age would put his max HR closer to 160, but treadmill tests indicate that his theoretical max is still in the 180 range. Hmm... so much for drugs and alcohol doing permanent and unrepairable damage.

The average American certainly could not maintain 10mph for a full mile, but that has little to do with being 50 :)
George Irvine, former manager of the WKPP cave exploration team down in Florida (He and Jarrod Jablonski have done cave dives penetrating over 3 miles at depths to 400ft and with total in-water time including decompression in excess of 17 hours) is over 50, yet would have no problems being competitive with guys half his age in a triathlon.

Heh, I've probably got some gunk in my arteries that's probably caused some issues.

Last question: The knee thing... assuming I have nigh perfect knees (which I probably don't from walking/jogging around at 215lbs), how long do you think I could continue running in general before I'd see knee problems (lets say 16 miles a week over 4 days..)? I'd like to think the knee thing is a myth, but I would like to think severe damage comes from people poorly prepared and have bad execution (running on pavement, bad running style, etc.). Guess I get to find out when I'm 40 or so :p

You may never develop problems. I've run 50-60 miles per week for months and never had a problem. Thinking you're going to develop an injury isn't a good way to prevent it. Start slow and if get knee pain watch it and if it increases don't try to work through it.

In actuality, no, there is no limit. It depends on your conditioning level, and probably on damage done due to lifestyle in earlier years.
The classic formula for max HR, for example, is to subtract your age from 220. Lance Armstrong has a resting HR of around 30 or less (Bjorn Borg was in this league), yet when required, he can crank it up and sustain a heart rate well in excess of 180.
President Bush is in very good condition as well. His age would put his max HR closer to 160, but treadmill tests indicate that his theoretical max is still in the 180 range. Hmm... so much for drugs and alcohol doing permanent and unrepairable damage.

The average American certainly could not maintain 10mph for a full mile, but that has little to do with being 50 :)
George Irvine, former manager of the WKPP cave exploration team down in Florida (He and Jarrod Jablonski have done cave dives penetrating over 3 miles at depths to 400ft and with total in-water time including decompression in excess of 17 hours) is over 50, yet would have no problems being competitive with guys half his age in a triathlon.

Wow 30bpm??? I thought mine was low after a 3 month cardio/weight stint. Mine sits at about 55-60bpm when resting. I guess the heart is more efficient at pumping and transporting oxygen then?

Wow 30bpm??? I thought mine was low after a 3 month cardio/weight stint. Mine sits at about 55-60bpm when resting. I guess the heart is more efficient at pumping and transporting oxygen then?
I'm around 57-60 now, after 4 months. Getting down to 30 takes a lifetime of training and dedication... I'm sure it's not rare among the elite marathon/triathlon category of athletes, but it would be extremely rare among even the fittest of people at the local gym.

A lot of it is a matter of vascularization and low bodyfat. Fat is extremely difficult to pump blood through, and it is not well vascularized (if it were, liposuction would be fatal), but it does require blood to survive... it is a network of capillary beds. This is of course, by design, as fat SHOULD only be a temporary tissue used to store fuel, and was never intended to be a long-term part of the body.

With reduced bodyfat and improved vascularity, you get lowered blood pressure, which results in the heart not having to work as hard, which results in the resting HR dropping. I'd be very interesting to learn what Lance's BP is.