I can help you statistically analyse the test results of individual athletes.
In my opinion, group statistics should be left for scientific articles.
Perhaps scientists are most interested in general tendencies, however, coaches more care about the extent of changes in an individual athlete. Did he/she improve? How sure may we be that he/she improved? Is this improvement big enough to influence performance?
Until recently, I thought that the answers to these questions might be only based on coach’s experience. However, in works of Martin Buchheit and William Hopkins, I have found a statistical method which can give statistical support for our intuition.
It is Magnitude Based Inference (see article)
After some consideration and analysis I developed this method further and combine it with Bayesian statistics. That allows statistical analysis of group of tests.
I understand that coaches have no time to delve into math . Nevertheless, mathematical logic can be useful in assessing performance and in making decisions. So you can read article with relatively simple explanation of Magnitude-based Bayesian analysis and use online calculator.
Lactate and respiratory thresholds are widely used for prescribing exercise and monitoring progress.
One of the most popular ways for determining the threshold point on a blood lactate or respiration curve is the so-called D-max method. In this article you will find an explanation of D-max and a calculator that automatically finds it using your data.