I have a strong weakness in my legs after a long walk, what can it be?

It could be.....: time to close your computer and get a comprehensive physical exam with emphasis on the circulatory and neurological systems. Cannot be diagnosed online.

Possible pvd: You might have peripheral vascular disease causing blockage of blood flow, a condition called claudication. You need a non-invasive test called an ankle-brachial index to evaluate this possibility.

I have a number: of questions. Are you not used to such long walks and your legs are tired.? How long does the weakness last? How disabling is it? Are your legs painful, swollen or discolored? Are you more fatigued than usual? Are you taking any medications (such as beta blockers) that might be contributing. Do you have weakness elsewhere. I suggest you see a doctor to sort this out. It's complicated!

...Muscle Fatigue..: 41 y/o male says, I have a strong weakness in my legs after a long walk, what can it be? it is supposed that 'strong weakness' implies 'extreme weakness' in the legs. In that case that could be simple Muscle Fatigue. Expected sometimes; but one should make sure they are well Hydrated while taking long walks. It may also be necessary to see one's PCP for Laboratory work up if symptoms persist.