Hi
Welcome to the MedHelp forum!
If you are easily getting fatigued with accustomed exercise level then hypothyroidism, diabetes, heart problems, high BP and anemia should be ruled out first. If you become tired after unaccustomed exercise, then it could be age related and keeping drinks handy after exercise such as lemonade, juices etc will help. It would be good if you could get a complete body checkup, even if you do not have any obvious problem other than this fatigue. Hope this helps. Take care!
I'm 60 and walk 6 miles a day with lots of hills, and this doesn't happen to me even on the hottest days, so I doubt it's age related. Take care....
You may be getting dehydrated, especially if you take any type of BP meds with a diuretic in it. Next time you want to work out drink orange juice, or gatorade before and during and see if this helps. If it does then you are getting dehydrated, but you shouldn't get dehydrated that easily. It's worth a try.