Training & Nutrition - Need advice on my Base training : intensity&nutrition

I started this week my base training with some cross-country skiing. My main goals for this period is to ncrease endurance, improve my cardio-respiratory system and increase the presence of mitochondrias in my body.

After reading on the forum, I found some answers to my questions but not all of them. I've read that I should maintain a steady pace at 80% for 2hrs at submax. I'm wondering if it's necessary to not go over that intensity even if I can, meaning that I should ski at an intensity lower than my max in order to get the benefits of that specific zone. What happens if I pace myself at lets say 85% of my max HR? Will I get the same benefits (or even more) or will it just be a «waste of time»?

Keep in mind that because of the snow, I decided to complete base 1 on skis instead of on the bike for the endurance part of the training. I don't know if the HR% and training zones are the same for both sports.

Also, I would like to get some info on the duration of the training session. Is 2hrs obligatory or can/should I go on for a longer period of time? Do I set it depending on the races' length I'll be taking part in next summer, or do I just focus on the 2hr mark?

I believe I wouldn't have any problems lasting for 2-3hrs at 80% of my max but I don't think I could hold on for 3hrs at 85%. My question is, should I set a target intensity that I want to work at to get specific results that can only be obtained in a specific zone (80%) and keep going until I can't go on anymore, or should I set a time target (ex. 2hrs) and go at my max (ex. 85%) at a steady pace ?

I also have a concern about nutrition. Do I have to eat right after a training session even if I haven't emptied all my glycogen supplies? Will my body start eating muscles to recover because it doesn't have any «new» energy coming in or will it be able to recover w/o any problems?

Thanks a lot, any suggestions or comments will be greatly appreciated. BTW I'm 21 y-o, 155 lbs (looking to lose 5-8lbs of fat in the next 2 months). I've read some books about cycling and begin to have some knowledge of training :) I am intending to begin racing next summer : I began cycling last april and enjoy life even more since then :p

I've read that I should maintain a steady pace at 80% for 2hrs at submax. I'm wondering if it's necessary to not go over that intensity even if I can, meaning that I should ski at an intensity lower than my max in order to get the benefits of that specific zone. What happens if I pace myself at lets say 85% of my max HR? Will I get the same benefits (or even more) or will it just be a «waste of time»?

This is one of the misconceptions of base training. Going outside of a specific level doesn't hurt, and in fact it can help speed the adaptations you are looking for.

See the following chart in pdf format (http://bike.terrymorse.com/coggan-adaptations.pdf). From that chart, it's pretty clear that the training benefits you are looking for are produced more quickly at higher levels of effort. Specfically, mitochondria are best produced when at Level 4 (LT effort).

No it won't hurt to ride at 85%, but it's also a different kind of workout as well. One of the purposes of the endurance rides is to tax your energy system and make it more efficient at utilizing fats and converting into energy. This requires you burn off a lot of calories in a single ride, like 1500-2500 calories. Riding at an 85% pace is fairly brisk and you'd be hard-pressed to keep it up for 2-3 hours. After you've completely spent yourself, cramped up and gone home after an hour having only burnt off 800 calories, you've cheated yourself out of a long workout that would've been beneficial if you've been able to burn off 3x the calories. :)

In the early stages, you definitely want to put in at least one day of endurance. As you build more fitness and speed from the other workouts like sprints and intervals, you'll be able to hold that 85% pace for longer. At which point, your same endurance ride will occur at a faster rate without any problems.

then I guess I'm going to start with 2-3 hrs at a sustainable rythm 3x/week, and then 1 harder but shorter session for about 1-2 hrs at a pace closer to my LT, doing some tempo and long intervals of some 20 min. with short recovery in between. I'll see what happens after the first 3 weeks, increase the volume a bit and replace an long and steady session by an other light interval one near LT.

I'm also starting to the maximum strength period of my weight training, can't wait to see how much I'll have improved when I'll get back on the bike for outside rides in spring! Unfortunately, that won't happen before march-april...