You have worked jobs where you are on your feet all day. You may have worked jobs where you are sitting all day. By the time you are in your late twenties, you have worked the sit-down jobs and the standing and running jobs to the point where you cannot picture yourself doing either anymore.
Truth is, constantly sitting, constantly standing, and constantly moving on your feet as separate activities are not good for you at all. Constantly standing causes your lower extremities to swell, making it impossible to move without extreme discomfort. Constantly moving on your feet all day creates fatigue from which you do not fully recover, no matter how young you are. Constantly sitting for work causes problems with blood pressure, heart health, and a whole host of other problems. When you want a job where you have about 50/50 equal split with desk work and foot work, consider training for an intelligence analyst job. Here is what you would be doing.
It Is Like Being a Spy, Only Slightly Less Dangerous
Quite often, you are given a "target." You have to gather as much information as possible on your "target," and then report back to your field office. There is rarely any long-term engagement or personal interaction with your "target," but that does not mean that you would never be compromised while on duty. You have to be very careful about how you gather your information.
You Have to Analyze Your Information and Create a "Perceived Threat" Report
Once you have gathered as much information as you can on your "target" (which could be a location, but is more often a person), you head back to the field office to analyze the info you have. You have to figure out if the person or location is a threat to national security (yes, you work for the government!), and then write a detailed report about your findings and your personal analytical guesses as to the "perceived threat."
Your bureau, and the government as a whole, has to decide based on your report whether or not the threat has to be monitored regularly and often until there is no real threat anymore. You may spend half your time in the field gathering the information you need over several months before you return to the office and spend about a week creating your report. If things are quiet, you may be following up on several old reports and analyzing information on old targets to see if that information still applies.