One of the assumptions implicit in the calculator is continuous activity.
1974 calories in 4 hours is about 500 calories per hour. 250 calories in 30 minutes of strong consistent paddling is not unreasonable, but it is unlikely you could keep that rate up for 4 hours. Even if you were out on the water, I'd probably recommend scaling it back to being the equivalent 2.5-3 hours of active paddling.
The other thing to remember is that the standard convention for counting calories is to include your underlying metabolism as well, which is technically a double count. For short intense workouts, this double count is immaterial, but for 4 hours, this may represent 250 of those 1974 calories.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.
| current weight: 178.0