They're different. The treadmill is measured. You can meet challenges I'm told, so if you're training for a specific thing it doesn't let you off easily.

Outdoor running balances things out, uphill, downhill, the flat....and if you sprint a bit you can also walk a bit if you get tired, not so easy on a treadmill.

I don't have much to do with either these days as I prefer dance but if I feel a bit lethargic I'd go for a run along the esplanade a couple of miles.

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