First, I'll try to describe what you are trying to achieve in this "Phase I" training. Then, I'll try to summarize the execution of the training, in the knowledge that our ADD-riddled culture will prevent most readers from working through the whole essay I linked in the last post.
In the other long discussion thread on distance training, Africans etc, wetcoast asked about Hadd's and Snell's "discovery" about glycogen utilization, muscle fibre activation etc.
I won't try to explain any of the science, because honestly, my brain rejects anything to do with biology or chemistry, but I may use some scientific terms, hopefully correctly, but only to try to establih context, and not in any rigourous way. If anyone wants to debate the science, or quibble about terminology, they'll need to do it with somebody else, as I won't pretend to be expert in that stuff.
The basic thrust of the Phase I training is to work away, deliberately, at successively harder efforts, each in turn, after having "mastered" the lower efforts, to build a solid, stable aerobic foundation. In doing so, you improve (increase) the pace that corresponds to any given effort, and lengthen the time you can run at that effort at that faster pace.
The work is done progressively from below (i.e. squeezing from the bottom of the toothpaste tube). Over time, the pace at any given effort, as measured subjectively by perceived effort, or objectively by the HRM, will increase, and you will push all of your working paces closer together.
In my experience, this method is so effective in building aerobic strength that it really nearly ought to be considered cheating. Successful correct implementation of this training creates an aerobic "animal," who is ready to either run a decent marathon, or start into, survive and thrive on the really hard training required for shorter races (800-HM).
The biggest problem with this approach, in my opinion, is that it is largely counterintuitive, and most runners lack the patience to do it properly.
A final note before the Cole's notes summary, back to wetcoast's question about glycogen utilization. What happens over the course of this training is that you alter the fuel mix your legs use in delivering power for running. The untrained runner will burn glycogen (and thus generate lactate, which corresponds with fatigue but also serves as a secondary fuel source) at high speed, and rely little on fatty acids. The aerobically well-trained runner will burn a different fuel mix, drawing on fat to a greater degree, thus generating lower lactate at all efforts (than before) and preserving glycogen stores longer.
You can see this directly by doing lactate testing on an athlete at various stages of the training, or can infer it from HR levels and perceived effort versus pace.
Here's a Coles' Notes version of Hadd's base training, as I understand it and experienced it.
Keep in mind as you read this – it ONLY DESCRIBES the process of building an aerobic base, which may be lacking for a lot of runners. It doesn’t say anything at all about subsequent phases of training or race specific preparation.
Disclaimer – these are my words, not the original words of John Walsh, so misunderstandings from the original intent are mine. Refer to the original writing to clarify as necessary.
The basic principles are that workouts and easy runs should be based on appropriate effort, rather than pace, and effort is measured by watching the heart rate via a heart rate monitor. The body adapts based on how hard the heart is working, not what speed the legs are moving. The heart isn’t aware of external factors (heat, humidity, wind) the way the legs are.
Training is broken into different phases. In the base Phase (that this post discusses) you're working on your aerobic threshold (AeT), trying to nudge it closer to your anaerobic threshold (AnT). Later phases of training focus more on AnT and other things. If you skip (or cheat on) Phase I, you won’t get the optimum benefit of later Phases.
Base training concentrates on aerobic base development. It makes you stronger than an ox, and ready for later phases of training. All phases are mostly easy aerobic running, with (normally) two work sessions and a longer run each week.
Here's the gist of the base phase:
Buy an HRM and learn to love it.
Determine your HRmax plus or minus a couple of beats. You MUST know this number to get to work. Don’t guess or use textbook formulas. They’re useless. If you don’t know your HRmax, go to the track and do a good warmup. Run 800m all out. Suck wind for maybe 30 seconds, then run 400m all out. The highest number you see on the HRM during this workout will be close to your HRmax, within a couple of beats.
Start running at 70-75% of HRmax, or less, every day until you work up to being comfortable running 50 miles per week of easy mileage. At this point, you will begin to add in stronger aerobic work sessions. These work sessions will be guided by HR, not pace. Don’t worry about pace, but track it so you can see the improvement over time. Keep the HR within the intended zones.
Space the work days two or three days apart. The body needs this recovery time to be able to adapt to the work you’ve done. A “work day” would be either a workout, long run, or race. Don’t do more than three work days in a week. Often (ie. when one is a race or particularly hard workout) you will only do two work days in a week.
During base training, you concentrate on aerobic work sessions, and the idea is to "lock in" each HR range until you could run at that HR all day (well, 60 to 75 min) without slowing down. You do this progressively, starting with lower HRs and shorter "intervals," and over the weeks ratchet up the duration of intervals, total duration of work, and working HR levels, or maybe shorten the rest between intervals.
But don't move up until you've mastered the level you're already working at, which means being able to run more than 60 minutes at that HR without slowing down to keep HR below the target.
So you might begin the program (after getting to 50 mpw of easy running comfortably) working at 80-83% of HRmax on Tuesday and Friday, and stay with that level until you can comfortably complete an hour of work without slowing down, and knowing you could keep on going at that effort and pace. As the pace-HR relationship gets locked in, you can up the second work session to 82-85% of HRmax.
So week 1, maybe you do 2 x 20 min @ 80-83% Tuesday and then 30 or 40 min @ 80-83% Friday. Next two or three weeks, maybe stay at that HRs, but get the sessions up to 2 x 30 then 60 min continuous for 80-83% work, and then maybe start to ease in something like 2 x 12 min, 2 x 15, 3 x 15, 3 x 20, 2 x 30, 60 continuous for 82-85%.
Over the following weeks, work up into higher HR ranges, with similar interval progression (85-88%, and 87-90%).
Again, don't move up until you've mastered the level you're at, keeping HR and pace steady, and finishing knowing you can keep on keeping on. You want to finish every work session feeling fairly fresh, like you’ve worked but you know you could continue at that effort. If you feel spent at the end, you’ve gone too hard, and need to ease back.
Work at this until you're at about 88% HRmax for 60-75 min continuous at a steady pace (with HR staying steady over that duration) feeling like you can keep going, and you're an aerobic monster, ready to tackle faster training and racing.
Many people find the 70-75% of HRmax running to be too slow, especially at first. Some people find they need to walk some stretches (ie. hills) to keep it below 75%, particularly for untrained or young runners. Early in Phase I, if this is the case, it’s OK to keep the easy running at 80% or less, if 75% is really too slow, but over time you should get the easy stuff below 70-75% as the aerobic fitness improves, and then keep it there. If you’re running a hilly course, it’s OK to let the HR drift about 5-10 beats higher than the target for short uphill sections, but don’t let it stay there for very long, and keep the overall average within the target (70-75%).
Fuel is really important. The work sessions will gobble up glycogen (the fuel in your leg muscles). Eat/drink soon after all runs. Always eat well (lots of carbs) the night before and after a workout or long run. Always. Without exception. Your legs will thank you for it.
Incorporate doubles when the mileage starts to creep up there (maybe ~ 70 mpw for some runners, as an example). Instead of running 13-15 miles on an easy day, maybe run 7 in the morning and 7 at night. Try it once a week and see if you can manage to add more.
Warm up and cool down should be a couple of miles or so easy running for the aerobic work sessions.
Every third or fourth week drop the work sessions entirely and let your body absorb the work. Assuming all else is well, you'll see improvement after three weeks, but it normally seems to take up to six weeks at one level to really nail it.
You will find that pace at certain HRs will vary depending on conditions. If it is hot and humid, expect to run 10 to 30s/mile slower than you’d like or expect. Don’t worry about it – that’s just the way it is. On these days, stick with the target HR and don’t worry about pace. The heart has no idea how humid it is outside or what pace you’re running, and it doesn’t care either. The training effect is based on effort, which the HRM judges more accurately than your watch.
If you give this a go, you'll be amazed, over time, at how easy it'll become to run for 60 minutes at efforts that start out being damn hard. Improvements don't happen in linear fashion, but every six weeks or so, you'll have a "holy shit" moment where you ask yourself, OK where the hell did THAT come from?