1 run per week - optimal 5k training strategy?

[GavMoon]

Ok TheEd I did 3x1km today, with 90s of rest between them. I was aiming for 4:10-4:20 pace but it was dark and hard to read Garmin, ended up with:
4:09, 4:02, 3:59

This was probably a bit too fast. I was puffing hard on the last one and got a new max running HR of 184.

I think I’ll do 2x2km next week, any pace/rest suggestions and/or comments on today’s session?

Thanks,
GM