Training Easy Makes You Fast!?!?!?

I received the below email from an athlete that I coach:

Athlete:
I thought I was well hydrated and most of the high hr is drift toward the end. I ran yesterday (outside) and kept hr in 150's for first three miles and then it went into 170's after a few hills and did not go down much. Interval times were similar across all 6 miles (have not downloaded that workout yet). My rpe was low except for a couple long hills. Can a person compete over a long period of time with higher heart rates? Do I need more base work?

Here was my response:
**FYI - this athlete has an ATHR (anaerobic threshold heart rate) of 174 beats per min. Zone 1 = <148, Zone 2 = 148 - 157

I hear what you are saying. And you are not going to like what I have to say. You need to slow down your running so that you are in zone 1 - 2 for most of your training. By running in zone 3 and higher consistantly you are not training your body aerobicly, more anaerobicly. You will not improve your fitness by training in zone 3 and above all the time. All you will be doing is making yourself fatigued, overtrained and increase your chances of injury. It will take you having a ton of self discipline to train slower, this will require you to walk once your HR leaves zone 2 and climbs into zone 3. Training in zone 3 and above should be done in short durations and used to specificially develop your anaerbic (threhold, endurance) and muscular endurance. I am very confident that if you can hold back the reigns staying in zone 1 -2, your pace will eventually drop. If you chose to train in zone 3 and above you will not experience any gains in the endurance.

So to answer your question - yes, you need more base work in zone 1 - 2, that is the key. Now for your other question - can a person compete over a long period of time with higher heart rates? YES - but only after a base is laid. This base depends on the person. Take me for an example - when I race anything up to 1/2 Ironman distance or 5 hours and under, I am racing within 5 beats of my anaerobic threshold of 170 bpm - the whole time. This is what it takes if I want to be competitive in my age group. I do 95% of my training in zone 1 - 2. When I go hard during my training it is very, very hard. There is a huge difference for me when I go easy its very easy so that when I go hard its going to hurt.

Training easy makes you faster!!

Coach