When you step on the treadmill, make a commitment. Do, say, 3 miles a day. And don't get off until you finish. It doesn't matter what speed you're going. Just don't get off.
If I'm pushed, I'd also have to admit I don't like people with allergies. They just annoy me. There seems to be something far too self-centred about it. 'No thanks, I'm allergic.' Why not just say 'No thanks'? I wasn't asking for your medical history, I was just passing around the nuts. Trying to be