Phase 1: PBIM 2014

So Phase 1 of my grand N=1 experimentation ends with PBIM 2014. 

PBIM 2012: 6h 35min 

PBIM 2014: 6h 45min

Training Runs prior to PBIM 2012 fueled by gels & electrolyte drinks.

Training Runs prior to PBIM 2014 after I injured my foot at the end of June 2014

July 14 - 1 run at 4.7km

August 14 - no runs

September 14 - 1 run at 6km

October 14 - 5 runs at 5km + 11.5km + 5km + 16km + 21km (Penang Run Leg 2 - New PB)

All runs on empty, coconut oil and/or Generation UCAN Resistant Starch

The difference, in 2014 I guess I am part of the way to being fat-adapted. 

The grand experiment started in October 2013 with a 2-week carbohydrate intolerance test. However having taken ill and missing out on PBIM 2013, I kinda fell off the wagon. 

Beginning June 2014 following a foot injury I started to follow a more strict Low Carb High Fat (LCHF)/ No Sugar No Grains (NSNG) diet to try to get my body to be even more fat adapted and to reduce inflammation in the hope to recover faster.. But the foot injury means there is no running. This led me to use the stationary bike to maintain aerobic fitness and strength training in the gym to keep the body strong. 

Weight (kg) change on same caloric intake: The spike in Sept was from a business trip to Beijing :D - hmmm Peking Duck.... yummy - but notice how fast it was to recover.

Body Fat%

October 2014: 21km Penang Run Leg 2 - a cause for optimism

Fuel - 2 tablespoons Coconut Oil + 1 serving Generation UCAN pre-race + 1 capsule Endurolyte. 1 serving Generation UCAN + 1 capsule Endurolyte during race. Sugar trickle last 5km. 

Time - shaved 17 mins off my 21km Penang Run Leg 1 time from June 2014. 

Ran strong with stable energy throughout, no fatigue at the end and surprisingly no DOMS. 

There might be something in this "Strength Running" theory. 

PBIM 2014 Full Marathon - Respect the Distance

So I ran a poor 6hr 45mins :-( ........

With hardly any training time on feet......

With minimal slow released carbs and Endurolytes. Fuel:-

1 serving Generation UCAN + 1 scoop Whey Protein 2hrs pre-race.

1 serving Generation UCAN 45mins pre race

2 servings Generation UCAN over the first 4hrs of the race, sugar trickle with Gu Chomps for the remainder.

Endurolyte capsules every hour. 

BUT that is virtually the same time I clocked at PBIM 2012 with a full 3 months training behind me (though I probably bonked in that one). 

For PBIM 2014, the first 21km went promisingly well, clocking 2hr45min on a very conservative run-walk-run. 

At 26km, my feet started complaining.

At 32km, they gave up and compensatory muscles in calves and quads started to twitch of cramp. Decided to walk the last 10km back. 

Fueling was probably satisfactory though I think I probably mis-calculated the UCAN timing. But body muscles hurt like hell on the verge of whole-body cramps at the end. 

I am not sure exactly what the reasons were for the slow run:

- initial foot injury from end-June

- flare-up of the foot injury from some barefoot football with the kids just prior to PBIM2014

- lack of time on feet (did not do a 30km LSD as common practice) 

- strength training which was not running focus

- insufficient fueling (less likely)

Recovery:

1 serving Generation UCAN + 1 scoop Whey Protein immediately after the race. 

24hr slow cooked chicken broth, 2 eggs, 1 banana, left over brown rice for breakfast/ lunch

Coconut water& flesh + local pineapple + turmeric as anti-inflammatory smoothie

Electro-pulse massage

Keep walking (read shopping mall - Gurney Paragon why your escalator not moving).

And sleep. Lots and lots of sleep. 

One day later, pleased to say muscle soreness is greatly reduced. Not much fatigue felt. 

Some comments on PBIM 2014

The organizers should really stop making focusing on making this event "The Biggest....", "The Most....." and instead focus on making it "The Best Overall Experience". 

For FM I do not really have many complaints. I pity the front Women's Open runners who even with the staggered start time inevitably got came across our Men's Open traffic. I feel big mile markers are unnecessary. You know one way is 21km so the actual traffic mile markers at 100m intervals on the bridge is sufficient. Water stations were sufficient though I think runners themselves should learn to go down the line to get your drink instead of bunching up at the start of the station. There were some complaints of water-station volunteers to be inadequate but I did not notice this. Was glad to see many ice-stations on the return leg. Probably only criticism was how the toilets were arranged, the queue was cutting into the running lane.

One thing I must say, I do hope the organizers gave the bridge a good rinse after the race or else motorcyclist will be greeted by a "wonderful fragrance" under the hot sun.

For HM, totally missed this group but I can imagine the congestion for the first 10km at least and the water-stations.

10km - This was farcical. It was virtually a 10km walk even if your wanted to run. Especially near the turn-back point where 2 lane road became 1. 

My main criticism is to be pointed at the start/ finish line. 

- If you do not look at your Runner's Guide there are no signboards telling you where are the locations of the Baggage drop, finishing line etc. 

- The race sites are water logged and muddy.

- The finishing point was totally congested. For a slow FM runner, I was already suffering yet made to queue just to get my finisher's bags? All I want at that point was to get to my drop bag to rehydrate.  BUT the baggage drop was at the start site across a barricaded road. Worse, there finish site was so congested with runners and yet there was no signage on how to get out of there and back to the start site. I thought the organizers would use the Mainland end of the bridge for the start/ finish as there was a lot of open space there and was surprised they decided to start/finish on the island. 

- cellphone usability was virtually not-existant at the start/finish point. 

- traffic and parking was totally unorganized - some reports that feeder buses were inadequate. 

My friend has a more thorough write up here.

The FM route:
Hyper lapse 6x speed - PBIM 2014 FM Route, one way. 
0:37 - 10km U-turn
1:07 - HM U-Turn
End of video, FM turn back and do it all again.......

Phase 2: Whats Next?

- Work on getting body fat down to about 10-15%

- With the foot injury means looking more into Strength Running Training as opposed to Conventional Lydiard Run Training. 

- Explore Cross-Fit Endurance (not exactly same as regular Cross-Fit) with a focus on Running.

Book Review: Influx by Daniel Suarez

"Power Corrupts. Absolute Power Corrupts Absolutely" - Superman,  (Action Comics Annual #3 1991), quoting Lord Acton

Once in a while there comes a book that makes me drive round the block a few more times, drive a longer route home, be contented getting stuck at a traffic jam or at red lights or even running the extra mile, just to finish an exciting chapter. 

Daniel Suarez's Influx (Kindle | Audible) is one such book. 

I have always had a fascination with Tom Clancy and his Jack Ryan books, more so because the way he incorporates technology into the story line. In his era, it was the height of the cold war and parallel  advancement military technology & spycraft.

I find Daniel Suarez to be a similar kind of writer. He incorporates the use of technology of our era - computing, hacking, drones, robotics, etc while telling an absolutely thrilling tale. 

Influx highlights the dangers of concentration of powers - be it with a man, country or more predominantly in our times - corporations. 

Book Description from Amazon.com

What if our civilization is more advanced than we know?

The New York Times bestselling author of Daemon--"the cyberthriller against which all others will be measured" -Publishers Weekly) --imagines a world in which decades of technological advances have been suppressed in an effort to prevent disruptive change.

Are smart phones really humanity's most significant innovation since the moon landings? Or can something else explain why the bold visions of the 20th century--fusion power, genetic enhancements, artificial intelligence, cures for common disease, extended human life, and a host of other world-changing advances--have remained beyond our grasp? Why has the high-tech future that seemed imminent in the 1960's failed to arrive?

Perhaps it did arrive...but only for a select few.

Particle physicist Jon Grady is ecstatic when his team achieves what they've been working toward for years: a device that can reflect gravity. Their research will revolutionize the field of physics--the crowning achievement of a career. Grady expects widespread acclaim for his entire team. The Nobel. Instead, his lab is locked down by a shadowy organization whose mission is to prevent at all costs the social upheaval sudden technological advances bring. This Bureau of Technology Control uses the advanced technologies they have harvested over the decades to fulfill their mission.

They are living in our future.

Presented with the opportunity to join the BTC and improve his own technology in secret, Grady balks, and is instead thrown into a nightmarish high-tech prison built to hold rebellious geniuses like himself. With so many great intellects confined together, can Grady and his fellow prisoners conceive of a way to usher humanity out of its artificial dark age?

And when they do, is it possible to defeat an enemy that wields a technological advantage half a century in the making?

I highly recommend listening to the Audible Audiobooks version. Jeff Gurner's narration really brings out the persona's of the characters in all of Daniel Suarez's books. Its like our forefathers listening to War of the Worlds over the radio. 

Here is a video of some behind the scenes commentary between Daniel Suarez & Leo Laporte. Jeff Gurner is also present and gives an on camera reading of an excerpt from the book.

Triangulation Episode #140 

Other Daniel Suarez books

Daemon (Kindle | Audible) & its sequel Freedom TM (Kindle | Audible) - control of the Internet leading up to a Utopian society.

Kill Decision (Kindle | Audible)- productive use of drones, for good and for bad.

Podcast Notes: Top 5 reasons triathletes get fat

by Ben Greenfield Fitness (3 Dec 2013) 

iTunes Link

1) Consuming in the evening too much Starch, Sugar and Carbohydrate (except if you do intense workout in the early-evening before dinner)

2) Gut-flora/ bacteria imbalance - consume kefir, probiotics, yogurt, fermented foods etc to create good gut flora.

3) Pre-workout fuel - over fueled. Eating before light/ short workout followed by post-workout fueling. Water, amino acids, electrolytes are ok. No need to eat post workout as normal eating thru appetite over 8hours will replenish glycogen and electrolytes. Exception if you are doing more than one workout for the day. Consume more amino acids and electrolytes during and after long workouts to maintain weight and prevent muscle cannibalization.

4) Nutrient Density. Fuels lacking in nutrients will make you eat more and more calories. Check out whfoods.com

5) Consuming too much calories - even though on diet of healthy foods.

Other notes: 

- 4 weeks of caloric restriction to induce starvation mode and weaken the immune system

- Fat burning occurs when best when sleeping.

Apple & PrimeSense - Daemon future comes true?

      * Copyright Twentieth Century Fox Film & Dreamworks SKG

At the end of November 2013, official news came out that Apple acquired the 3D sensor company Primesense. Primesense technology was the cornerstone for the original Kinect sensor which could tell how many people were there in a room, where they were and tracking their movements enabling them to interact with the Xbox game console.

Most of the reports speculate that Apple would use the sensor to look at the user such as in an Apple Television Set/ Set-top box, in a retail environment where the sensor can "see" where you are and how you interact with a product and even gesture control (ala Leap Motion) and 3D user object scanning from an iOS device. You can read more about it here, here and here.

What if....

What if the device Apple envisions does not look at the user but is embedded in a wearable that "sees" what the user is looking at. 

Imagine the Oakley Airwave but maybe in something simpler like a pair of glasses.

     * Copyright Marvel & Paramount Pictures

Holographic projections in air for an audience to view is at the moment not practical much less mobile. 

However imagine if this holographic projection is for the benefit of the user alone.

Imagine full screen projection on the lens of the glasses instead of a small screen to the side. 

Imagine that this encompasses the full field of view of the user. 

Imagine the projection is in full 3D space so that it objects does not obscure the user's sight of real objects. 

The Primesense sensor can detect your hands in real-space in front of you. You can now manipulate icons, menus, objects in real-space in front of you - like Tony Stark. With Bluetooth LE connection to your iPhone or Mac, you now have powerful computational power at the backend.

The Primesense sensor can also map objects in front of you. Your iPhone is constantly connected to the world (Internet), already knows where you are (GPS), your orientation (Compass), your movement (Accelerometer) and has context-aware ears (Microphone + Siri). Now it can have context-aware eyes (Primesense sensor). With enhanced Apple Maps or Google Streetview, you can now have metadata projected 3D on the objects in front of you. 

Which brings us too the Daemon future. 

Daniel Suarez authored a thrilling book titled Daemon and its sequel FreedomTM. What is more fascinating to me is the technology described is very plausible with what we have today. With respect to the eyewear, it is a combination of the glasses described above + social media + MMORPG (World of Warcraft, The Sims, Second Life). 

The user is able to use it for:

- viewing, listening and interacting with virtual objects/ characters projected over real-space. Think Google Ingress game (Link, Wiki), virtual tours in Museums and cities etc. The book describes it as “Temporal Offset Projection, an interactive 3-D avatar projected over the GPS grid. It's only visible and audible in your HUD glasses.”

Imagine the presentation is being virtually projected on your glasses in 3D space on top of your real view of a real world beach and real world audience.

Layar is halfway there using the camera's in our phones.

*photo source








- navigation with turn by turn directions projected in virtual-3D space in front of you.

- full iPhone functionality, instead of touching a screen you use voice-control and multi-touch objects in the "air" as the Primesense sensor accurately tracks your hands and fingers.

- Internet connection so the user is able to retrieve information, navigate websites, use Apps and in the story conduct malicious hacking. 

What interest me more was the social media + MMORPG aspect integrated with the wearable glasses technology.

In the book, the massive online community is connected to each other via a "Darknet" 

The Darknet is an encrypted, distributed, and resilient network that Daemon operatives use to communicate. The operatives on the Darknet are able to "see" into d-space through a heads up display that maps objects onto the GPS grid. Communication is primarily wireless and uses ultra-wideband and WiMax to transmit information. Logging into the Darknet requires biometric authentication and all communications are secured using high quality encryption.

Members of the Darknet have an occupation which dictates their level of advancement. Members are able to rate each other using a five star reputation system which is visible to anyone on the Darknet. The rank is a simple average of the number of stars and the base is the total number of people who have ranked an individual.

Darknet Classes - Fighter, Sorcerer, Shaman, Rogue, Scout, Fabricator, Journalist.

Today there are virtually 2 billion active users among the various social media services.

Whenever we want to look up a product review, movie review, news, commentary - we scour the internet. Popular blogs, websites, commentary already get promoted and pushed to the surface via Likes, Shares, Retweets, Pins, Follows, Friends etc. Like-wise insightful writers have their reputations enhanced similarly. What if reputations can only be promoted by verified genuine users? Youtube comments already take this first step by requiring only Google+ comments which require real ID. What if we can expand further this reputation system to create classes in all fields of expertise to make our world a better place - educators, scientist, sportsman, governance etc.

Currently this reputation system is siloed within each proprietary service. What if like the Darknet, we can gamify life? Via the glasses we can instantly request for the name call out of the person we are interacting with either standing right in front of us or remotely, what are his expertise, what is his particular reputation/ rank. The glasses could instantly recognize and present the name call out for someone talking on the news. Who is he? What is his reputation? And in real time the public can up-vote or down-vote the message his is conveying.

Or with business, we can see the name call out of a business in a particular building? What offers are on? In real-time, what the public think of that offer?

Value of a person, object or message could transcend propaganda, censorship, bias advertising, falsehoods etc.

       * photo source

        * photo source

Think of it as an extension of a game like Second Life but with real people and projected in virtual 3D Space over  Real World GPS grid.

Now if only they could incorporate the eye-tracking technology Apache Helicopter pilots use to aim their weapons into these glasses..... oh and also an awesome Daemon & Darknet :D

And a Haptic Vest would be real interesting too.

Note: Links to Amazon are Amazon Affiliate links. 

Note: The technology depicted in Daemon and Freedom^TM may seem like science fiction, but it actually exists 

Two Week Carbohydrate Intolerance Test

Two Week Carbohydrate Intolerance Test

2weeks = Weight Lost 5kg, Body Fat Burned 4%, Waistline reduced 2.5inches.  

I have been on a predominantly Whole Food/ Vegan/ Vegeterian diet (5 days on, 2 days off where possible) for about 18 months now. Exercise has been basically running about 5hrs a week. 

Weight loss from a peak of 91kg in Feb 2012 to an average of 81kg before the start of the test. Body Fat % loss from about 27.5-30% down to 25-27.5%.

The purpose of the Two Week Test (TWT) is to evaluate whether I have carbohydrate intolerance (CI) and/ or whether I have been overindulging in carbohydrates in light of my advancing age.

This TWT will also help indulge my curiosity whether;

- a Low Carb-High Fat (LCHF) diet can further improve physical endurance and ability,

- effect of carbohydrate on blood-work,

- reset body to avert Metabolic Syndrome (Pre-diabetes).

The Two Week Test is designed by Dr. Phil Maffatone. 

You can read more about how he developed the test

http://philmaffetone.com/how-i-developed-the-two-week-test

and about the actual test protocol itself.

http://philmaffetone.com/2-week-test

The TWT is not a diet where you carry on perpetually. It is recommended to conduct it for two weeks and slowly introduce back carbohydrate rich foods slowly after that - see which ones instigate a physical response in your body. You go about doing this by totally avoiding certain carbohydrate rich foods such as grains, starches, fruits and natural & synthetic sugars.

The TWT does not mean you will be hungry. You are to eat to satiety on vegetables, meat, healthy fats and oils from whole UNPROCESSED foods (more whole plant foods the better). You can see from my meal plans below that my caloric intake remains normal.

The TWT also does not mean that you are 100% carbohydrate free as you still obtain more than adequate carbohydrates from vegetables, nuts and seeds.

Weight on 5th October 2013

81.3kg, 26.5% Body Fat

After a 1 week food transition to carb free,

Started TWT on Monday 14th October 2013

80.1kg, 22.5%

Day 4/5 - felt the most tired probably as body switch from sugar burn to fat burn. 

Day 7 - Ran 1hr 4.74 miles at Max Aerobic Fitness heart rate. (142bpm). Felt abundant energy and was difficult to go slow to maintain heart rate. I feel anything more than 90mins I would probably needed some water and carbs. 

1-week - 24th October 2013

77.2kg, 23.7%

Day 11 (25th October 2013)

76kg, 23.2%

Breakfast Smoothie at 9am, still did not feel hungry at 1pm

Day 13 (27th October) - 22mile run. 5hrs 15 mins, 4700 kcal burned.

It is ok to consume carbohydrates during this exercise as most will be used up immediately. Hopefully as I was towards the end of the TWT, most of the benefits will already be achieved. 

Day before the long-run, I ate additionally about an extra 100gms of carbs.

1hr Pre Run - 188 kcal, 40gms carbs

During run - 785 kcal, 121gms carbs  ingested, about 4700kcal burned

Recovery - 296 kcal, 62gms carbs

Total for the day - 251gms carbs.

Intended to run at MAF HR (below 145bpm) but HR at start of run was already 20bpm higher than usual. Not sure whether it was lack of sleep or consuming food 1hr before run. Ended up running around LT zone (160bpm) increasing to about 170bpm when fatigue set in. I did not feel bonked at all but quads were not conditioned and started to cramp at Mile 21. 

Day 14, 75.5kg, 22% body fat 

Day 16, 30th October. 75.6kg, 22.7% body fat. Morning of scheduled full medical check up. 

(Weight on 5th October 2013 was 81.3kg, 26.5% Body Fat)

From the blood-work, Total Cholesterol dropped even though I ate more fat and 2-3 eggs per day! 

Details 

There is the possibility of weight loss  due to water loss. Glycogen in the muscles hold on to water, so when this is burned off, so will the water. Seeing that Body Fat% dropped or maintained makes me think water was not the only thing lost. I did feel more  thirsty (so drinking more), probably from the higher ratio of protein and sodium in my diet. 

Tracking my weight and body fat % over the past 3 months 

Pre-14th Oct generally weight above 81kg, body fat between the 25%-27.5% range. 

During TWT 14th Oct to 30th Oct, weight dropped to 75-77.5kg, body fat % between 20%-22.5% 

1st Nov - 11th Nov -  I re-introduced grains and sugars as carbs. A small rise in weight.

11th Nov - 17th Nov - Fell sick from overtraining. Body weight on 17th Nov was 74.4kg, 21.8%  (almost 7kg drop form 5th October)

18th Nov - 25th Nov - Business trip with less control on food and alcohol intake  followed by the inevitable weight gain. 

Below was my nutritional consumption during the TWT. 

Comparing with my Fitness Goals calculated using myFitnessPal, my weight should have maintained (or at the most 0.4kg loss) each week. However,  I burned off about 2kg per week. Note the ratio of carbs:fat:protein by the myFitnessPal app is calculated on the current US RDA.

Compare that my diet for the past year. 

This was for a typical day on what I thought was a healthy vegetarian diet of a Fruit-Heavy Green Smoothie for breakfast, rice + 3 types of stir fried vegetables for lunch and more rice + vegetables for dinner. (I will reserve my thoughts on vegan/ vegetarian/ paleo diet on a separate post). Lots of sugars, carbs and unhealthy cooking oils. No wonder my weight and body fat % plateau even on a 5 day per week exercise routine. 

Below was a typical day’s meal during the TWT. Mainly whole plant foods, healthy fats from nuts, seeds and fatty plants like avocado. Carbs are also from whole plant foods. 

And this was my consumption on the day of my 22mile run using mostly home made fuel.  

Breakfast - 2 tablespoons honey + 2 tablespoons chia seeds + 2 capsules electrolytes. 

1st 3hrs of run - 4 tablespoons honey diluted to 6% in water. 

2nd 3hrs of run - 500calories of Phil’s bar made from homemade ingredients.

GU Gel consumed at mile 20 in attempt to stave off cramps.

Recovery drink = Coconut water + banana + L-Glutamine

For  the rest of the day. Interestingly I did not feel the usual cravings for carbs or the usual low in energy.

Wrapping is up

- The Two-Week Test does show that as I live a relatively sedentary office lifestyle, perhaps there is some merit to eating a lower carbohydrate diet.
- Energy levels during the TWT, especially during the send week was extremely high. I worked on my feet at a standing desk practically the whole week while including single-leg balance exercises hourly. Could be a mental thing. 

- Energy levels for endurance type exercise was perhaps better with a Low-Carb High Fat diet particularly when the body is fat-adapted. 

- By eating nutrient dense foods from whole plants and health fats and oils, I felt satiated for most of the day just from the breakfast smoothies. Hunger pangs were eventually nonexistent. 

- Lost cravings for nightly potato chips or chocolates. Could be a mental thing. 

- Eating Nutrient-Poor foods led to eating more calories throughout the day. Rapid weight gain noticed.
- Consuming too much high-carb foods such as rice does produce insulin spikes, followed by crash (i.e. afternoon siesta's ).
- While body weight has stabilized, waistline still seems to be on the decline. 

Going Forwards

- I will continue with a Low-Carb, High Fat diet, incorporating No Sugar, No Grains as much as possible. Carbohydrate consumption will probably be higher than during the Two Week Test.

- To investigate whether how a Low-Carb diet affects higher intensity activities. Perhaps there is a need to increase Carb consumption to around 150gms per day or a better optimum level. 

- To observe whether a Low-Carb, High-Fat diet can eventually increase HDL and lower LDL & triglycerides (as theoretically supposed to)
- To monitor protein levels and muscle mass to avoid cannibalization of muscle tissue. 

(Disclaimer: I am neither a qualified medical practitioner, certified dietitian, nutritionist or fitness/ sports coach. Above views are my own from personal experiences and from what I've read, seen or heard.)

Miracle Tea

This is partially what I have been pumping myself for the last one week in order to try to recover for the 2013 Penang Bridge International Marathon (PBIM)

1/3     cup loose green tea leaves (preferably Chinese)

1        teaspoon whole peppercorns (can optionally replace with mint leaves)

2-3     plump stalks lemongrass, smashed (optional)

4-6     inches each ginger and turmeric, washed and thinly sliced (you don't have to peel them)

3 to 3.5 liters/quarts boiling water

Steeped in boiling water for 12hrs.

Full article/ description here

My last bout with chest infection gave me fever for 2 weeks, and 2 courses of antibiotics. This time round, fever for 3 days and no antibiotics. Was it due to the tea, my diet or the strain of the virus? Go figure.

(Disclaimer: I am neither a qualified medical practitioner, certified dietitian, nutritionist or fitness/ sports coach. Above views are my own from personal experiences and from what I've read, seen or heard.)

Heart Rate Variability: I should have listened to my body.

Heart rate variability (HRV) basically tracks the differences in length of time between each of your heart beats. I will not get down to the exact science of how it is measured. A Google search will give better explanation than I would. The gist of how HRV works I obtained from here. 

"

Heart rate and rhythm are largely under the control of your autonomic nervous system, which is split into two branches, your “rest and digest” parasympathetic nervous system and your “fight and flight” sympathetic nervous system. 

Your parasympathetic nervous system influences heart rate via the release of acetylcholine by the vagus nerve, which can inhibit activation of SA node activity and decrease heart rate variability. In contrast, your sympathetic nervous system influences heart rate by release of epinephrine and norepinephrine, and generally increases activation of the SA node and increases heart rate variability. 

If you’re well rested and haven’t been overtraining aerobically, your parasympathetic nervous system interacts cooperatively with your sympathetic nervous system to produce responses in your heart rate variability to respiration, temperature, blood pressure, stress, etc. 

But if you’re not well rested (overtrained or inadequately recovered), the normally healthy beat-to-beat variation in your heart rhythm begins to diminish. This variability indicates sympathetic and parasympathetic nervous system balance, and proper regulation of your heartbeat by your nervous system.

In other words, the delicate see-saw balance of your sympathetic and parasympathetic nervous system no longer works. 

In a strength or speed athlete, you typically see more sympathetic nervous system overtraining, and symptoms such as:
 - High cortisol & insulin
 - Low testosterone & DHEA
 - Fluid retention and swelling
 - Highly variable HRV (heart rate variability number bounces around from day to day) 

Comparatively, in endurance athletes, you typically see more parasympathetic nervous system overtraining, and symptoms such as:
 - Adrenal exhaustion (low cortisol, low insulin, low testosterone, low DHEA)
 - Weight loss
 - “Rest & Digest” overstimulation
 - Low HRV (the heart rate variability number stays consistently low)
 "

This was my HRV on the morning of 10th November 2013. Though I felt a little tired, I foolishly went for a "short" 1hr training run. 

The next day I promptly fell ill with a chest infection, runny nose and fever. The above shows my attempt to rest and recover. However as of Sat afternoon, 16th November 2013, a low reading together with lingering feeling of fatigue, cough and itchiness of lungs, I decided to rest and forgo racing 42km at the PBIM. 

Whether the chest infection would have flared up in any case even if i had rested? I do not know. Perhaps. But weakening the immune system further certainly would not help. I will keep a closer eye on HRV in the next year.

I use Azumio's Heart Rate iOS App with Stand-up Test to record my HRV.  A more accurate reading would be to use an ECG accurate chest strap with systems from iThlete or Sweetbeat or similar.

(Disclaimer: I am neither a qualified medical practitioner, certified dietitian, nutritionist or fitness/ sports coach. Above views are my own from personal experiences and from what I've read, seen or heard.)