It’s easy to track your effort using a heart rate monitor on an elliptical machine and if you use low resistance you can mimic running fairly well. You can use it to transition from pool-based cross-training to running if you’re coming back from injury, or you can use it to supplement running you’re already doing.
Most gyms have one – if your college one doesn’t then ask around the Hareys (on top of that the university sports centre gym is pretty well kitted out with everything).
If you’re using the elliptical to supplement your running, you don’t need to try and mimic running sessions, but if you’re using the elliptical when you’re coming back from injury, you need to get your heart rate up to what you’d do in a session (the key is to keep the recoveries short). Example sessions could be:
Eilish McColgan has some good advice on how to use elliptical machines here. One key point she makes is that even if you’re reducing the injury risk by using an elliptical, you need to be aware of chronic fatigue – all because you won’t get an injury from doing a tough session every day doesn’t mean you should. Also, given you’re indoors and in the same spot for a while, this is the time to get into some music or podcasts (or even good old daytime TV).