sudden improvement

is just for curiosity.
in the last 2weeks i started a High fat/low carb diet, for a body recomp and because a friend want to do same photo of me.
in the last 3 weeks i started a training to improve my fitness and my flex, and to improve the flexibility of my right leg and hip flexor because it is very thigh compared with the left one. i started to do a lot of stretch, drill A, and tempo run, now i can do 2200 with low fatigue.

so, suddenly I improved my time in 40 m (5.5), in my tempo run (i did 20 approx, and today i did 17" approx), and in my other hobby (goalkeeper of soccer) i noticed an incredible improvement of my performance (in pratically one week).

what of the 3 point can be the key of this improvement?
1.increased flex
2. the diet who make me lighter (on this diet i weight 3 kg less because i lost wAter)
3. the improved fitness (but it don’t explain the improvement as goalkeeper)

i know isn’t too scientific…but like I say is just curiosity.