Irregular behavior - feeling of losing power

My '95 Corolla has 210,000 miles but has never had a problem - it is a 5 speed stick shift. About 10-12 times over the past 6 months, it will feel like the brake is on - when I start or sometimes after I have been driving 10-15 minutes. It will drastically lose power - I have to shift down and put my accelerator down and the temperature starts to rise and it feels like it is driving ‘rough’ - some vibration - and then all at once (maybe 5-10 minutes) it will just release all at once. The last 2 days it has done it so I am concerned. Ideas? I asked the dealer last summer when I had it in for a 200k tune up and he said everything was great - no problem and couldn’t recreate it.

It could be sticking brake calipers, collapsing rubber brake hoses, or junk in the brake fluid clogging the ports in your master cylinder. If it happens more frequently, eventually someone will be able to reproduce it on the lift. If you do get a hose or caliper replaced ,make sure they bleed and replace ALL the brake fluid.

To confirm or rule out a brake problem next time try letting the car coast, clutch released.
Does it slow down quicker than normal?

At this age and mileage I would suspect ignition parts:
distributor cap & rotor (if it has them), ig wires, coil, ignitor.
Plugs have been changed a couple of times by now, right?

Thank you for your response. I have done that test and my car will NOT coast when it is in this state - If I am going down a steep hill and I put it in neutral it will still act like I have a brake on and slow to a stop - and the same thing happens if it is in gear with my clutch engaged. I could be stopped on a steep hill - in neutral - and it will not roll.

SO - does this mean it IS a brake problem?

Yes - I have owned this car since it was new and have had all regular mainentance done on schedule.

does this mean it IS a brake problem?

Yes, go with what oldtimer said above, plus:
Next time it happens carefully feel each wheel (the metal under the plastic cover if applicable).
If one is hotter than the others you know where the problem is.
In the future change the brake fluid every 3 years

Thank you so much - it is really good to have a confident answer.
I have an appointment at the dealer for next Wednesday - meantime next time it happens (probably today or tomorrow) - I will stop and feel the metal if I am in a place where I can pull over!!!

THANK YOU again!!