Long hikes/ extended workouts.

Because you are building muscle from the long hikes!

If you want a really accurate measurement maybe get a heart rate monitor. I always make sure that I get a couple of MFP quotes and use the middle range.

Hey my question is in regards to the accuracy of calorie burned estimates from MFP, Heartrate, and Map my run. I perform extended hikes from about 6-8 hours with a single 30 min break in each. I've done 4 so far in the past two weeks and on each one I travel from 20-30 miles depending on the difficulty of the slope. Based simply on an average pace of 3.5 for a total of 6 hr.s MFP states I burned 2000 calories while based on my average heart rate of 115 of my HRM it says I burned 3482 and Map my run says I burned 4432 calories based on distance terrain and elevation change. Which of these do you believe is accurate?

This is the start of my 3rd week of dieting and for the past 2 I've maintained a 1000 calorie deficit BMR to maintain my current weight and haven't eaten additional calories to make up for my daily runs/hikes. Yet my weight has actually creped up a few lbs any reason behind this? Perhaps my digestion is slowing down to better absorb the little calories that I am consuming? Or perhaps my extended hikes has caused my cells to store a lot more water making up for the weight. Either way it's not a big issue as I can see improvement just wondering where the weight is going.

Interesting one, this. I hike most weeks for several hours and up a few thousand feet (usually involving lot of rock scrambles). I use an HRM and usually burn around 2,000 calories but, of course, this depends on age, weight, sex, inclines etc.

While my heart rate does shoot up when climbing, I'm aware that some of this might be technically strength training (clambering up rocks, rather than walking along at a fast pace as I do on other "cardio" bits of the walk). My heart rate also never reaches the rate it hits when I run, even though I find climbs more exhausting. As such, I do think my HRM might overestimate my calorie burn.

Because of the water retention due to muscle repair my weight usually goes up a few pounds the day or two after a hike, then I get a whoosh as it goes back down (so it often goes up 4lbs then drops by 6lbs later in the week - so a net loss of 2lbs).

I'm a bit confused about your calorie intake but you do need to make sure you are fueling your body for such an extended workout.

For me that means setting my TDEE at sedentary, eating 20% below that and eating back all my exercise calories. It's quite easy on hiking days as I usually take quite a bit of high-carb food and also tend to drink in the evening

If I were you, if your hikes tend to be cardio rather than scrambling I would set the calorie burn as per your HRM and eat back at least half those calories.

Give it a couple of weeks and see how you get on.