Arrhenius equation in Kinetics and Thermodynamics

It is always stressed that one should never mix Kinetics with Thermodynamic. How is it then possible to calculate the free energy of activation with the Arrhenius equation? As I understood, the Arrhenius equation and thus the activation energy of a reaction "belongs" to kinetics, whereas the free energy represents a term of Thermodynamics.


An example of the calculation I refer to can be found on page 7 of this link:
<http://cbc.arizona.edu/classes/bioc460/summer/460web/lecture/EnzIntrod_11.pdf>


