Drop 54s 400m to a 52 in a few weeks?

Probably not, no.

That is like dropping 4 seconds off your 800m or 8 seconds off your mile, in a few weeks.

Depends on how you've been training, and if you have any weaknesses to exploit:

1. Use a 3 point start. There's a good youtube with Jeter showing exactly how to do it. Many distance people trying the 400 give up at least a second right at the start. Also, get a sprint timer (reaction timer) app on your phone and use it to practice doing the first 50-80m. There's an app for iPhone and for Android.

2. Race modeling. Clyde Hart way is to push out hard for 60-80m, stride out to 200, pick up to set up the stretch sprint from 200-300, and hold your form and relax in the final stretch. If you go out too hard in the first 200, there's some you can gain there.

3. 2-4 X 400 at around 800 pace. The workout I've used is 3X400 at almost 100% with 4 minutes. This is HARD, and you might not be able to do a whole lot the rest of the week, but it works great setting up a peak. John Smith has a version of this which is 3X350 with 3 minutes. Sebastian Coe did 4X400 at 800 pace with 3 minutes, which you can do if you ARE Coe.,This workout can wipe you out if you do it too many weeks in a row, but for once a week for 2-3 weeks, you WILL gain something, particularly if you speed endurance is not what it needs to be. If you try this workout make sure you talk to your coach and make sure he knows it, otherwise your overall training could be waaaay too hard.

I like 1 and 2, but I think the best single session to do once a week is this (no.3 seems much more of an 800 session to me):

3 x 300, or do 300-260-230 the first week, and 3 x 300 the following week. You could possibly handle 3 x 300 straight off.

12 mins rest.

Do them with a 10m roll in, and you should do all of them in 39.0 or 38-high. You will get used to running fast.

Once you can do all 3 at 38-high or 39.0, you should be able to go 52.0.

Oh, also, do 200 sprint training if you're not already.

Presumably you're much better at the mile, so forget all about running the 400 in season, as it would hurt you for the mile.

A standing start will be fine and more relaxing for you at that speed.

A good workout for 400 is 3x 250m with 10 to 15 minute rests, walking slowly for recovery. Anything longer would not be that helpful for your speed.

Be careful to not overdo it.

My #3 above was originally a 400 meter workout from SMTC and was 3X400 with 3 minutes rest. The reason it became 3X350 with 3 minutes is that they had too many people (that's pros) throwing up on the track on a warm day, so they cut it to 3X350 with the same rest. John Smith still uses this for 400 and there are slight differences for 400 and 800. It is a VERY hard workout, but if you need something that works quickly, this works quickly. Intensive tempo (80-85% with 5 minutes) or special endurance (90-95% with long rest) will work, but require more time.

BTW, like probably many others here, I competed in college and then went away from the sport after graduating. In my case, I went climbing in Nepal for 15+ years and only came back to running for conditioning for my last 2 climbs, ran in a few road races (1 HM in Colorado being the longest). After I had not been on a track for 15-20 years and obviously was really slow, I joined a running club that had 1 track workout a week, got a new pair of sprint spikes and started doing this one workout (3X400 with 4 minutes) once a week. I went from being almost the slowest person on the track to the absolute fastest in ONE summer. If it doesn't kill you, it WILL make you stronger.

Yes. Dropping 2 seconds off of a 54 isn't that much even if you were to not use blocks. But with blocks and good weather conditions, you'd be surprised how much you can drop.

Good luck