No problem at all.
I suppose adb sees your phone given that it has the proper adb usb driver installed. So you should see logs coming from your phone into logcat (you can find them in 'Android monitor' subpane of Android Studio).
Certain version of android may connect the phone in PPT mode, you can go to settings -> storage -> usb connection and change it to Camera mode so that adb can detect the device. After building the project, hit the play button, then select your phone from the list that pops up (assuming that adb sees your device) to install the apk to it. When installation completes, the app should be shown in foreground and you can start playing with it. This should work the same as your Hello World App.
Additional info, in case you want to use gradle instead:
1. select import from existing project (Eclipse, etc)
2. pick import from external model "Gradle"
3. While selecting the source code directory of the project, do not choose the top level directory "ANT+ Plugin Sampler", instead navigate into this directory and choose "source"
4. Do anything to make the import wizard happy, mine nagged about AntPluginLib.jar missing, so I removed that line from project.properties then accept all default options.
5. At the project window, hit F4 to open module settings then add all of the necessary jar references, namely: android-support-v4.jar, antpluginlib_<version>.jar and fit_16.00.jar. Note that the jars need to be placed somewhere within the project directory, so I made a libs subdirectory within source. The first image shows how my gradle file looks like.
Note: If you want a better name for the directory instead of 'source', you can rename the source directory to something else before starting step 3.
Hope this works for you.
Image Attachments
Click thumbnail to see full-size image