Fever after running

I am a healthy 32-year old male, work out regularly in the gym, and run for about 40 min. to 1 hour once a week. Twice in the last few months I experienced fever few hours after running. It felt like a beginning of the flu (muscle aches, fever, lack of energy), but with no cough, sore throat, etc. Fever lasts for about a day, and I feel lack of energy for one more day, but after 48 hours from the start of this condition I feel absolutely healthy. Except for those 2 times, I never developed a sudden fever. Hydration should not be an issue.

So it might be a coincidence, but I'd like to know if there's possibility that there's a connection? What can it be?

[Dr Vinod]

Hello,

Sometimes due to intense exercise like a 1hr cardio will get your body to secrete endogenous factors which cause fever like interleukin 1 a cytokine and also interleukin 6 and other pyrogens and prostaglandin E2.

With time and rest you would feel fine and for this the remedy is to acclimatize your body in a continuous way. You need to walk or do some amount of cardio in a more regular way than an intense workout once a week. Try doing some cardio on alternate days and one day intense in a week. Your body acclimatizes over a period of time and there is decrease of these endogenous pyrogens and factors and then you can continue this regime.

I am not taking into consideration any viral or external pathogens which cause fever taking your history into account and also taking into account that your thermometer is working fine. Consult a physician if your symptoms continue.

Take care!