Muscle Fatigue

Question
I think my question may have been answered in Arial's issue from just a few days ago.  But, it is possible I am experiencing something a bit different.  I've been training for a 10K following this schedule: http://running.about.com/od/racetraining/a/10Kadvbeginner.htm
I was unable to complete one earlier run because of a side stitch and researched/corrected that problem (gulping too much water right before the run#.  Early on in my running #prior to this effort and at the beginning of it#, I had some knee sensitivity and swelling post-run.  I took my rest days seriously and I had felt my knees were getting stronger over time and giving me less problems as I went along.
Then, however, we come to this morning #Tueday of week 5 - a four miler#.  Before I even finished the second mile, my right knee didn't want to go on.  I stopped to walk and when I tried to run again, the left knee made it clear it was all done, too.  I finished the four miles walking #had to get home, after all# and have been experiencing extreme muscle fatigue in my legs since.  Getting up and down from my desk chair takes some effort.
I suspect this has to do with my diet as I have been fasting for Lent and eating just one meal after sundown each day.  However, I've made it a significant, well-balanced meal #most days!# and it's not hindered my training up until today.  If anything, I thought the early morning run would be easier having just eaten dinner before going to bed #most days I don't run until closer to 3:30 PM when it's been more like 15 hours since my last meal).  I drink plenty of water throughout the day.  Could there be any other cause besides diet?  I will have three weeks of "normal" meals before my race.  But, after this morning, I feel pretty nervous about the whole thing (whereas yesterday I thought I'd be ready without any problems!)!

Answer
Wow - there's a lot going on here.  There are three problems you touched on : a side stitch, a knee issue, and muscle fatigue.  Let's take them on at a time.

1# Most side stitches are related to your breathing, not what you recently ate or drank.  They are common in people who are new to running, and tend to diminish in frequency over the years.  #Although some veteran runners occasionally have to deal with them.#  When a side stitch occurs, one thing that I have found often works is controlled, deep exhalations.  The next time you get a side stitch, slow down your pace a tiny bit, and take slower and deeper breaths.  On the exhale, try to force out more air than your normally do.  Sometimes it helps to grunt or groan a little towards the end of your exhale, as this helps to force out the last bits of air.  You may sound weird while doing this, but it can usually resolve a side stitch in a minute or two.

2# There are many different things that might be causing your knee pain.  You might have some type of structural issue in your knee that is acerbated by running.  Or the supporting tissues around your knee might be weak and/or inflamed.  There is really no way I can tell from an e-mail #nor am I a doctor#.  However, I can say that many people have running strides that will, over time, cause joint problems.

Perhaps you have heard about the barefoot running movement?  Or at least the move towards more minimalist shoes?  The basic idea behind these movements is that shoes with large, cushioned heels allow people to run with an un-natural stride whereby impact with the ground is first made with the heal, with the leg in a mostly-straight position.  This causes the impact of your foot hitting the ground to be transferred straight up your leg through the bones and joints.  Try running barefoot for a hundred yards on pavement, and you instantly discover how painful it is to run this way!  

Try this exercise.  Make a fist with your hand, and while keeping your arm straight, gently punch a soft surface, such as the back of a chair.  This action will feel jarring to you - you will feel it in your elbow, and in particular, your shoulder and back.  Now do the same thing, but keep your arm bent when you punch.  Allow your arm to bend a little when your fist lands.  This will not feel bad at all.  In fact, you could punch much harder with this technique if you wanted to.

The same sort of thing happens with your legs each time your foot hits the ground.  You can significantly reduce the wear and tear on your legs by simply shortening your stride and making sure your foot hits the ground while your leg is slightly bent.  Just as with your arm, this will reduce the impact forces transmitted through your joints and bones.  Ideally, the part of your foot that first makes contact with the ground should be the ball or mid-sole.

When running this way, you will notice three things.  One, you will run a little slower.  This is because your stride is shorter.  Two, your calf muscles will get sore.  This is because they are short #from years of shoes with built-up heals# and not used to having to absorb the impact of mid-sole or toe landing.  Three, you will get tired faster.  This is because when your foot makes contact, your leg flexes a little #just like your elbow did in the punch-experiment#.  In order to stop your leg from flexing all the way, your muscles have to contract in order to counter-act the flex.  This means that the impact of your landing is handled by your leg muscles, not your joints, which is as it should be.  Muscle is designed to handle large axial forces - your joints are not.  But this also means that your leg muscles will be doing more work than before, so you will tire faster.  Don't worry though, in time you will adapt to this stride just as your had to adapt to the demands of recreational running.

My suggestion for your knee would be to lay of running for a little while and allow it to heal.  Any pain and inflammation needs to subside.  Once this has happened, try running using the stride I described above.  It often takes a little while to un-learn your old way of running, so be sure to be vigilant.  Run for shorter distances than before and see if your knee is aggravated.  If everything goes well, then you may be home-free.  If your knee problems return, you may need to see an orthopedic doctor to found out what is going one.

3) Your muscle fatigue is mostly likely related to your diet.  Severe caloric restrictions that reduce your total daily energy expenditure #TDEE) by more than 20% are going to make you feel miserable.  In addition to total calories, the timing of food is extremely important.  Running in the morning before breakfast is hardest to do because your are the furthest away in time from your last meal.  And running 15 meals after your last meal is going to be even harder.  Is there some reason why you are doing this to yourself other than Lent?

You may have been able to get away these strange eating patterns for a while, but as your metabolism changes #and it will change for the worse if you are eating far below your requirements, or forcing long fast-times between meals) and your glycogen levels deplete, it will all catch up with you.

First of all, you need to eat on a regular schedule.  If you are only eating one or two large meals a day, stop.  Break this up into three or four meals, spaced evenly starting with when you get up in the morning and ending before bed.  You can do this without changing the quantity of calories you eat - simply by make each meal smaller.  You will feel much better.  I understand you may have religious reason for eating the way you do, but your body doesn't know anything about religion, and it is going to respond in the same way that everyone's body does faced with dietary stress.

Second, you need to eat nutritiously.  You've said that you have been eating a "well-balanced" meal.  What does this mean?  What is the percentage of fat, protein, and carbohydrates in this meal?  How many calories does it contain?  What types of carbohydrates?  Simple high glycemic, or complex low glycemic?  Perhaps your energy levels might benefit from a diet higher slow-digesting complex carbs, such as those found in oatmeal and beans.  Perhaps you need more fat in your diet.  There抯 really no way for me to tell.  Analyze your diet to understand what you are eating now.  Then, since you only have a little time until your big race, take a shortcut and lookup the diets of other runners.  You may be surprised that the quantities and types of foods are quite different from what you have been eating.  Trying eating a similar diet and see how you feel.

Good luck!