Is it possible to improve running performance for army physical fitness test without much running?

Evening

2400m (1.5mile) time trial

Time: 7:44

Even though I have not been running regularly for the past 2 months ( I think only total of less than 10km), I was able to maintain (technically improve by 1s) my timing for this time trial. I am using the same route, the only difference is that I ran in the evening whereas the previous time i did so in the morning. Prior to this trial I did a morning kettlebell workout (see previous post) and I did this trial in a hungry state (it is past my dinner time).

When I burst off from the start, I could feel so much "spring" in my legs. I felt light and fast and powerful. I had not felt anything like this for the past two years, when I was clocking massive mileage on the elliptical and on the pavements of Singapore. During the run, though i stumbled a little probably cos I was overstriding alittle due to being a little "rusty" from running, I felt that I still had the capacity in me to run. When I crossed the line I was breathing heavily but no where near state of collapse.
From this time trial, though it was a self experiment, I came to a conclusion on some of the key training areas that had helped me achieved this performance despite such low mileage from running:

Firstly is the maintaining of exercise intensity. Although I had not been running as much, I have been doing alot of high intensity training (Crossfit and calisthenics circuit training). These sessions ranges from 10 minutes to an hour. Oh, and lot of burpees. I feel that burpees is one of the  BEST exercise that can quickly destroy you in a workout. The next two are the Kettlebell Swings and Kettlebell Snatches. These 3 are my favourite exercises if I want to have a killer workout. This keeps my cardiorespiratory system strong and maintain a high work capacity. This is essential for a time trial like this as it is a short period of intense activity and is probably why i can last the trial at a furious pace (for me at least)

Secondly, it is due to several exercises that I have done. They are the Kettlebell Swings and Pistol Squats. The Kettlebell Swing is actually a very great tool to develop the muscles that you use for running - the glutes, hamstring, lower back and a very explosive hip thrust or snap, which is crucial for running. That is probably why I feel so explosive off the start. The Pistol squat will develop the quads and the stabilising muscles in the legs which will make running feel easier as well. Afterall, running is, when u break it down, a series of one legged hop.

However, I feel that the timing could have been better if I had thrown in 1 or 2 interval sessions of running every week. One session of 200s/400s and one session of 800s or 1000s shld be able to bring my time down abit more as I would be more accustomed to the pacing and improvement of my running economy, not being so "rusty". All these will help to conserve energy by running as efficiently as possible and will translate to an improvement in running times in your PFT.