Maximising your Fitness Devices

I've been using my Garmin 910xt since April 2012. To date it has served me well. Short of the ability to accurate record swim data in open water condition (due to my inability to maintain a consistent freestyle strokes), the GPS watch with ability to record more than sufficient data has helped me improve on my runs and analyse it.

Garmin 910xt Full Review, Here

Apart from the purpose of the device to record your usual running parameters and heart rate, there is one function/feature that resides in all Garmin devices (aka not limited to just Garmin 910xt, click here for the complete list). Training Effect or TE is a parameter used by Garmin and a few Heart Rate manufacturer to monitor and feedback to the user the quality of their workout.
About TE
TE were developed by this company called First Beat. Based in Finland and they specifically does lifestyle monitoring devices. What they do is to offer measurable matrix (aka quantified data) to be used for lifestyle improvement such as stress management, rest management and obviously, sports performances. A detailed explanation of TE can be obtained at the First Beat website where the TE was conceptualised and put into each performance gears. The whole idea is to allow you to "Train Smarter, Not Harder". Though i believe there is no shortcut to these, it doesn't harm to understand some of these training parameters readily available for you - since you already own the device/s.
How Did TE helped me (personally)
To improve your fitness level, you need to exercise. And by going out to "just run" or "just cycle" will not put enough load and stress to your system; and in return, accustom your body to it. These prolonged stress and load applied on a constant successive workout will build your base and improve your overall fitness. TE is measured between 1.0 to 5.0 As with every sets of statistical number, two points give a straight line and more points will be needed to give you an accurate measurement. With this in mind, the TE number for first time user will or might appear to be higher. The reason for this is because TE is a direct relation to your Excess Post-exercise Oxygen Consumption or EPOC. This is also known as the exercise "afterburn". The real reason why you are still burning energy while resting after exercising. EPOC has always been an expensive quantitative measurement that are usually done in lab (think of gadgets strapped on you while exercising/stress test on treadmill). It is also a direct relation to your VO2max and heart rate. With the TE, your EPOC can be predicted - thus allowing you priceless data to either push harder or take it easier in your next workout.
Pushing Harder? Or Taking It Easy
I am a strong believer to recovery after a hard workout. The body needs time to build and repair itself and you can only maximise it that much without falling into the abbys of exercise - Overtraining. Of course there are ways to get out of the rut, but why go there in the first place? TE provides priceless data for you to gauge your current training. As they are broken down to five-level, you can "relate" to your workout better.

The TE Table. Taken from Garmin Website

A good example would be my race for Malakoff 12km where I did a TE5.0 - an overload with high improvement workout. As I've conditioned myself to be able to sustain this stage (aka "care taken"), I can confidently pushed myself to that stage - and there will be much room for improvement.

Can't possibly get higher

What I then did the day after the race was to just go for a short run on very low effort (level 1 out of 5) to just "flush" the lactic acid out from the system. The low effort recovery run correlates to TE 0-1.0 where the heart rate will be at low limits. I will continue another easy day and start my training at TE3.0-4.0 before building up to yet another TE5.0 come this weekend when doing Hill Circuit Interval. 
Bottom line
Some athletes (social or otherwise) are secretive about their training regime. While most of it aren't rocket science, it will help that we all do our own research and read up to understand what needs to go into each exercises and how to maximise the time spent sweating (and sometimes, crying) out there. It is important to "COMMIT" to the activities and treat each workout with respect - as you would not done yourself any less injustice by injuring yourself while out working out.
As this is a technical write up with links to medical and sports studies, the resources below were read, understood and summarised to produce this write up. The sources were from: 
EPOC and Interval Training - A master thesis
First Beat TE White Paper
First Beat EPOC White Paper
Oxygen Consumption in Sports (VO2) - a basic understanding of VO2