So, here is what I found so far, to summarize:
- Time between last meal and beginning of training - Ideally more than 3 hours
- minimal ideal weight - smaller portions - keep your weight in the lower range of your ideal - for me by experience, I now know that it's in the 68-70 kg range - this could be even lower in the coming year
- Rest and sleep - a night with less than 5 hours sleep will have a huge impact on your energy level while you train.
- missed some training session - for instance, if you don't train for a 2 weeks for practical reasons, you will feel that you need way more will power to achieve the same results
These are some core fine tuning elements.
When you start training and are only at 40-50% optimization these fine tuning elements matter way less.
The core limiting factor will probably be 10 or 20 pounds extra body fat or simply being out of shape.
However, when you are in the 80-100% optimization range, the 3 elements I mention above become essential!!!
To compensate, you can always use your will power and force it.
However, when you are taking care of these optimization elements, then you enter into the fun/energy zone.
This means that you feel that your training is effortless.
It becomes super enjoyable and almost exhilarating.
Also, these strategies apply to exercises like jogging, swimming, cardio, and the kind of training I do in the woods with intervals, exercises, etc.
If you are on the weight training and body building mode, the rules might be different because you are trying to build up bulk muscle.