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July 2002 | SFI Endurance = 100%

superfit index™

Quality of your bodyweight on a scale from 0 to 100%

Superfit Index (SFI™) is a unique algorithm that rates your bodyweight in percentage. No complicated measurements are needed to make the analysis. Your age, height, weight, gender and body composition are taken into account and combined into a single number, your personal Superfit Index (%).

You need to log in at this point and have your Superfit Index calculated to be shown your results when you read this article.


Information you enter assigns you to at least one of the four possible criteria:

    > Level 1		Homo sapiens
    > Level 2		Fit human
    - - - - -
    > Level 3a		Superfit Endurance
    > Level 3b		Superfit Strong

We will return to these bodyweight criteria again as I write more about each later in the article. Additionally, for deeper understanding of your own results we shall analyse a fairly typical result from a person that trains on a regular basis. What follows is an actual result from someone who I will disguise simply as Joe. Let us take a look at Joe's results.

    90.0 kg / 186.0 cm / age = 39
    Fit Human        86.5 %

Most would be — as they should be — more than happy with such result but there is nothing wrong in working to improve it even further, especially if you are training on a regular basis. To give you a more clear picture how to improve — your Superfit Index™ — you additionally get valuable info what to change and work on if you work towards your theoretical 100%.

    fat mass        5.0 kg lose
    muscle mass     2.5 kg gain
    weight change   2.5 kg lose

For Joe to reach his ideal bodyweight all he needs to do is lose an additional 2.5kg of bodyweight.

Similarly to Joe, when pursuing a better body majority is left wondering how is it that once they finally reach their desired bodyweight — even when they go so far as to reach what they believed to be their ideal bodyweight — results are rarely as ideal as the term ideal bodyweight implies.

life is suffering @ get better at it

quality of ideal bodyweight

another way to explain what Superfit Index tells you

There are three principle strategies how Joe — from the case above — could reach his ideal bodyweight which demands he loses only 2.5kg of bodyweight to attain his ideal 87.5kg.

    A. lose 2.5kg of body-fat                      SFI =  94.2 %
    B. lose 2.5kg of muscle mass                   SFI =  81.1 %
    C. lose 5.0kg of fat + gain 2.5kg of muscle    SFI = 100.0 %

All three examples above lead to reaching the exact same ideal bodyweight yet their Superfit Index™ results are different.

Its easier to explain basic principles for achieving Joe's desired bodyweight by idealistic A-B-C case scenarios as I have chosen above. They are not exactly 100% scenarios you might achieve but they are illustrative to how things would play-out.

Here is a quick assessment for each of the three different strategies used to achieve Joe’s ideal bodyweight and why this lead him to three very different results.

  1. Awesome goal: Majority usually tries to achieve just that, lose primarily body-fat while loosing bodyweight which is indeed an excellent goal in most scenarios. If Joe would succeed the quality of his body composition would improve by a large margin — Superfit Index would rise from 86.5% to 94.2% — very close to his ideal result.

  2. Worse option: How you lose weight matters. If Joe would lose primarily muscle to drop those 2.5kg — his Superfit Index would drop from 86.5% to 81.1% — the quality of his body composition would be worse — at his ideal bodyweight — than it was when he was 2.5kg heavier to start with.

  3. Perfect plan: The only strategy which attains that drop of 2.5kg of bodyweight and delivers theoretically ideal 100% is the hardest and takes the longest even though all you need is to lose those damn 2.5kg of overall bodyweight.

mother of two who works harder then 99% of all men

How to best achieve results for any of those three strategies, to explain in depth those A-B-C principle strategies, how to best improve the quality of your bodyweight is beyond the scope of this “introductory” article. There is however a great deal to discus in regards how to achieve any of those result in practice. For example; What is the best way and how long it takes to lose 2.5kg of pure body-fat and stuff like that but this calls for another extensive article which I am excited to write as a follow-up.

father of three entering the age gate of 40

superfit index™ method invention

You need to log in at this point and have your Superfit Index calculated to be shown your results when you read this article.


After thousands of questions about what’s my ideal weight, how much should I lose, how much muscle do I need, etc. I decided to make everyone's life easier by creating a tool which delivers highly individualised, yet easy to understand answer.

The first algorithm was developed all the way back in 2004 and was done with the help of Excel spreadsheets coupled with some simple programming. More than 1.000 body composition measurements that I had done in the years via different methods gave me a huge pull of data to build that first initial model to start with. In the years that followed I have made improvements and many subtle tweaks, which forced me to build a more robust adaptive model with databases, individualised age grading and a solution how to “magically” guess a person body-fat even if I can't measure it or if like many of you — you just don’t know it. This is why I need you to answer that one question — if you workout, yes/no and then ask to choose an answer which best describes your recent habits.

Anyway, I imagine that most of your are not interested in technical details which geeky side of me enjoys. Best then to tell you more about how superfit analysis work, when you are penalised, when rewarded and which are the four main criteria by which your bodyweight is judged.

fear of pain must be conquered on a regular basis

who gets penalised

General population that drives their bodyweight either far too high, or far too low to be considered healthy. The goal is to find a good balance. If you find your self in close to obese or in obese category your result will tell you to lose a huge amount of bodyweight. Ironically there are cases when someone's bodyweight is far too low, even clinically so and to increase bodyweight by considerable amount is suggested.

Specialised athletes, even though you might be in great shape for your sport, being specialised for something specific will highly likely result in lower result than you might expect or feel is deserved:

  • athletes who need to maintain low bodyweight to increase their sport performance;
  • athletes who are specialised for strength and need to carry more muscle mass and/or weight to perform at their best in their discipline;
  • bodybuilders and even physique competitors as the level of achieved muscle mass and other applied manipulation results in naturally unattainable, unsustainable and non-health results;
  • females that have body-fat levels bellow essential healthy level — which is 10-12% for a female — will get a lower score for going to low;
  • natural freak cases which are too unique to be judged by criteria I came up with.

if it were easy it wouldn't be worth pursuing

who gets rewarded

General population which works towards attaining their suggested ideal body weight by — in most cases — lowering their body-fat level and building some muscle. Those looking to upgrade their goals from primarily getting enough movement through their day by adding at least 2-3 workouts/week to build their strength levels and improve overall conditioning.

Non-specialised athletes

If you find your self not being married to neither sport but rather enjoy the freedom to work on everything with a solid and challenging program that includes:

  • basic bodyweight gymnastics
  • old school bodybuilding
  • pure strongman stuff
  • endurance sports
  • add anything

conditioning, strength, mental toughness and pure grit

bodyweight criteria

There are four main criteria and depending on information and measurements you provide — you will be assigned and judged by at least one. Here are the main bodyweight criteria:

  1. Homo sapiens criteria judges you against hypothetical ideal body composition of someone who doesn’t do any serious training but still tries to look after own health by achieving good amount of daily activity and maintains balanced eating habits.

  2. Fit Human is already notably harsher in judgement than initial Homo Sapiens criteria. Its designed primarily to judge those who train on a regular basis and value towards both athletic body as they do physical performance. High result in this category already puts you well above majority of those who train regularly.

  3. Superfit Endurance is the original category that started this whole project and stems from the period of my life when I was pushing the limits of my conditioning to — at least what I believed to be — my maximal genetic potential, while retaining as much muscle as possible. Lean and strong athletic machine. Leading image (July of 2002) for this article is an example of 100% score in this criteria.

  4. Superfit Strong is the category which was my personal pursuit while transitioning more into strength. The goal being to build as much quality muscle and strength as I can while not neglecting good overall endurance and conditioning. When you are as close to the top in this category as you can be you should be at your strongest and fittest overall level. Strong and mean, not bulky yet still muscular with a big endurance engine to carry all.

July 2002 | SFI Endurance = 100%

Some of you will be assigned only Homo sapiens criteria; some will be assigned Fit Human criteria in addition to Homo sapiens criteria, meaning you will see your result for both. Obviously a high result in Homo sapiens criteria will always be far easier to achieve than a high result by Fit Human criteria. Still it can be useful to see how you do in both to have a clearer idea how far you’ve come or where to go next.

Its not uncommon to be assigned to both Superfit Endurance and Superfit Strong criteria. Generally you will notice you do much better in one than the other. For example when I achieved 100% by Superfit Strong, I only got 91.5% by Superfit Endurance. This is normal if you are tilting more towards one than the other. You can not be best by both criteria simultaneously but you can have a very similar result in both if your are somewhere in between.

Superfit Endurance and Superfit Strong are the harshest criteria by which you are judged. While similar in their extreme nature, one tilts more toward endurance, other more towards strength, both demand you are exceptionally balanced and extremely fit overall.

September 2018 | SFI Strong = 100%

final words

No matter where you find your self, the goal of your Superfit Index™ result is to serve not only as a judge but also as your guide. You might not be happy with current results but if you were to improve you would probably appreciate that a tool exists which will confirm and reward your hard work.

You can always come back to Superfit Index™, evaluate your progress and use it as a guide for further improvement. It has been a brutal but honest judge for me through many years. It compliments my training philosophy perfectly and if I were to explain my training philosophy to you there is no better way than with my life motto.

“Specialised for nothing, ready for anything!”

Doomed to eternity I answer questions which people imagine hold a secret ingredient to how I do things, something they have been missing all along. The more truthful my answer, more disbelief some seem to find. Informations most are accustomed to consume are built on very little truth but abundance of disinformation, half-truths or twisted facts which promise high reward for little effort.

Speak the truth and people seem confused, offended and you less popular. Live a meaningful life, share lessons learned and learn along the way, better your self and encourage those around you to become better then they were yesterday. Superfit Index™ is a challenge, an invitation for personal responsibility and my gift to the courageous souls.

Marck Goran Lorencin © all rights reserved