This is a common occurance. One can turn on the Internet and almost daily find tips on relaxation and tension removal. So, considering how many of us are exercising and meditating like you, do know you are not alone.
The basic reason this happens is one you are probably already aware of: when the environment changes, so does the experience.
Although you may exercise and meditate with great concentration, you do so in physical circumstances very different from those in "everyday life." Much of the tension released is likely garnered from exposure to psycho/physical environments almost opposite to those you relax in. Re-exposure can quietly rejuvenate this previously released tension. The key is to find ways to reproduce your relaxation space off-site.
Using the senses can help. Take a moment out to try the following steps with your eyes open or closed:
See your surroundings. What is to your right, in front of you, to your left?
Smell the environment. Breathe slowly.
What do you hear? Music, the outdoors, the voice of the instructor, a chant or repeated word?
Can you feel what you are sitting or standing on? Can you feel the surface of the floor, mat or road? Is there a particular temperature? If you run, can you feel the impact on your feet? Can you recreate your clothing and what is on your feet?
I remember a story my acting teacher, Lee Strasberg, told of a well-known film actress who, before rehearsals, would play a record off-set to elicit a specific emotion. After several weeks the time came for the actual shoot. Just before the take, the director told the actress to play the record, but was surprised when she said she no longer needed to hear the actual music, as by then, "the tune was in her head."
This same technique can work for the layman. Taking a moment to re-create the environment in which you meditate and exercise can help you reconnect with the results --
no matter where you are.