The past few rides I've participated in, I have really struggled physically during the first 5-10 miles. What I mean by this is I will sweat profusely, feel a bit weak/lightheaded and feel just overall BLECCCH. After I get past this, and usually after my first rest stop for a Clif bar, I am O(plenty of energy and not sweating near as much) for the rest of the ride for the most part as long as I stay hydrated and eat. FYI, I have been eating oatmeal/toast/OJ for breakfast before I leave out. Time between that meal and when I first start the ride has been ~an hour both time.

Any suggestions what this could be?

Dunno what's happening, but here's a kludge:

Ride to the rides, or if too far, get there earlier and do a 5-mile out and back before the ride.

I personally would need a more substantial breakfast than that to feel good about myself but I know people that get by on that.

I think it's kind of weird but on a hot day I takes me longer to warm up.

It takes me 10 miles to really get into a groove. If you ride with a group that starts fast it can be a real suffer-fest...right at the beginning! Lately I've been doing some faster rides and they begin 5 miles from my house, so I ride to them at a nice relaxed pace to get in some of the warm-up miles.

Similar to the above post: I don't know why it happens specifically, but I feel your pain. Definitely takes me 10 miles or so to start feeling like I have any power in my legs.

Interval training and/or hill repeats!

I have had the same problems and these helped tremendously!

My normal weekday ride is a 32 mile loop 3-4 times during the week, with a 60+ mile ride usually on Saturday morning. I replaced one of my weekday rides with hill repeats. This is by far the most difficult day of my week and I have to force myself to do it, but it has made all the difference in my average speed, sprinting, and the problem of fatigue early in rides.

YMMV.

I found that if I eat before riding, it seems to kick my body into a "Feed me, Seymour" mode. I have to keep eating. If I don't, I bonk. However, if I don't eat before riding, my system relies on its energy stores and lasts for up to 2+ hours before I need to start eating.

As I said, YMMV. So play around with it. Also, get warmed up before the ride as others have said.

I usually drink a muscle milk shake before I leave (which I am about to do actually), and that seems to be enough food for a while. However... the first 5-10 miles still sucks. My cruising speed takes a while to get to my normal, which I think contributes to feeling bad in the beginning, because I feel so slow. I have found that looking down less at my speed seems to help a bit, and I can feel when my body hits its groove. Then I don't notice how slow I am, and feel a little better.

I think it is normal what you are experiencing. I usually feel good after several warm up miles. There have been times I didn't click until around 20 miles, an off day for sure, but most rides start out slow for me.

I'm not sure how to answer the OP but I'm sure glad that I'm not the only one whose ride sucks during the first 7-10 miles.

One thing that may help.

Try forcing your breathing.

As a jogger, I learned that it was really important at times - particularly right at the first of a run and/or before going up a big hill, etc.

Force breathing out - really push it out - As in making a shout on the exhale.

Then after ten or so breaths start sucking in also.

Then keep a measured tempo - heavy breathing, basically a military double time cadence - you've heard them shout them out. You will normally breath in somewhat - but you will not normally force the air all the way out. Doing so, increases oxygen supply to your system primarily to your muscles.

My theory is - early on, your blood stream and system are behind the curve on supplying oxygen to your muscles - this is what makes it tough during the early part - When you smooth out, your system is supplying enough oxygen to your muscles.

When a runner "hits a wall" it is usually that he/she has entered an oxygen deficit situation. No way to win on this one. Have to stop and recover. However, if you force your breathing - you won't hit that wall -

I'm talking recreational running here, not olympic marathon runners, they may well tell you different.

I'm 65, and this system is what has made jogging roughly fifteen miles a week work for me.

Biking - not exactly the same, but in some ways this has helped me a lot - I will start breathing deeper before a grade - and as I go up, pushing harder - I breath harder and force it - and have no problems with the grade. No real hills on my route.

Worth a try, not saying it will solve your issues - but in fact may well make your situation a lot better.

try warming up before the ride. You see TDFers on the trainer prior to a time trial? Guess why.

Our group doesn't go hard until at least 30min. Warmup before you meet the group.