Running two days in a row?

Hi Guys,

I've just decided to get back into running & hopefully keep at it with a view to attending my local 5k Parkrun soon.

Anyway, I've been doing 2 runs a week in between my gym days for 3 weeks now.  This week I'm out the gym for one reason & another so I thought I'd do more running this week. Now, I want to keep my long run on a Saturday but I don't really want to have a 2 day rest during the week! Would it be ok to do a 20 minute run tomorrow having run for 30 minutes today?

It'll probably just be a one-off but I guess I'd still like to know at what stage it is ok to run two days in a row?

All my training is aimed at building an aerobic base at the moment, so I'm running slowly & even having to walk a couple of times to keep my heart rate in the right zone.

I'm not an absolute beginner... I did a reasonable amount of running a couple of years ago but then was sedentary for 1.5 years for health reasons. Since then I've done a few runs here & there but mostly just walking. Over the Christmas period I walked 2-3 miles every day almost, so I'm not a stranger to doing some form of Cardio!

I'm 26 & male if that makes any difference.

Thanks guys!