i've been trying to keep my training consistent over the past few weeks, getting up early and doing about 13-18 miles every morning. i'm alternating "hard" days and "easy" days.

yesterday i did 13 miles at an intense pace, was not sore.
today i did 18 miles at easy pace (higher cadence) and my legs feel like concrete. it was supposed to be a recovery ride.

my diet includes a good amount of protein and water.

i tend to overdo things and hurt myself. so before i go out tomorrow, i want to just check in - what would you recommend i do? take tomorrow off?

Aim for at least one day per week off ... or perhaps doing something other than cycling, like a nice stroll round the block ... in order to allow your muscles to recover and rebuild.

So what's your goal? If you want to train and get better, i.e. faster, you need a plan and schedule. just riding day after day is fine, but won't necessarily make a faster or stronger. There are lots of training plans and schedules out there, just look. diet is of course a big part. some sort of recovery drink after the ride is not a bad idea. after any workout there is about an hour or so that you have to replenish what you body has used up. lots of various recovery drinks out there too, even stuff like Cytomax and Endurox R4.

keep working at it. get a plan, follow a schedule.

do you have a heart rate monitor? the best thing to do is to look at your resting heart rate when you wake up. if it's high, rest.

+1 on taking a day off, coming up with a goal and a plan to meet it, and replacing electrolytes, glycogen and all that other nutrition stuff

A few other things to check:

Was your route different? You tax your muscles differently on a hill than you do on a flat road, regardless of intensity. I've found this out the hard way by noticing that I can do anaerobic sprints (flat road) one day and ride a hilly route below threshold the next and be fine but I cannot do it the other way around (<AT hills followed by >AT flat) - my muscles are too fatigued from the climb even though from a HR standpoint it was an "easy" day...

Are you sure it was an "easy" day? How are you defining and measuring that? I am not a big fan of HR monitors but I always wear one on easy days. The hard stuff I trust myself to knock out, no problem. But it's really, really hard to keep my recovery rides easy. You should be able to breathe through your nose and comfortably carry on a conversation.

rest day, maybe two

rest is awesome for growing muscle. do it and you'll feel stronger.

with weight training you take 48 hrs off between intense sessions. I know its not the same blah blah blah, but its relevant