What to do with vastly different exercise level days?

Fat0605

Hi folks, I have just joined this group after reading some of the posts and I really like the concept of eating more (especially after several disaster very low calorie diets a few years ago!) I have about 45 pounds to lose and am just trying to figure out if eating at TDEE - % (ie the same calories every day) or letting MFP set my calories but eating any adjustments passed over from my Fitbit is better for me. I am currently training for a half marathon and am running three times a week (2 shorter and one long run which will be up to 10 miles) but the other days I am not very active (desk job, bit of housework, 10 minute walk from car park to work but that's about it). I'm worried that if I use the TDEE method I could potentially undereat on my longer run days and then overeat on rest days, or does this not matter as the week will average out?

I suppose my main question is if the TDEE -% method is better for people who do the same exercise every day and have roughly the same calorie burn and is it better for people like me to let MFP give me extra calories on my running days?

Any help is much appreciated

Thanks

Gillian

heybales

You would be undereating by too much on day you need the recovery - as well as overeating too much on pretty much any non-exercise day.

Indeed, bad combo. While thinking about it - make sure you lose the deficit the week before the race - no diet needed then while you taper.

You could approach the idea of proper fueling/recovery 2 ways.

Fitbit method.
Use a reasonable deficit for your avg TDEE from Fitbit NOT counting the big run day. That's what you'll have to tweak MFP with.
I'd confirm that Fitbit reports correct distance for your average pace run, when run on a known distance track - not treadmill.
Since calorie burn comes from distance, and distance from step impacts - need that stride length setting for running to be correct for avg speed you do. It'll adjust up and down from a middle point.
Then just sync and eat adjusted.

TDEE tweaked method.
Again use your avg TDEE from Fitbit not including the big run day. Just need avg. You'll have to unsync accounts.
That's the TDEE to take deficit from and eat that daily. Makes it easy for planning hopefully.
Except on big run day.
Take whatever that day is for TDEE, and just take off the 15%.
You'll be looking more at your device on this day, or the Fitbit app - and doing the math to reach 15% deficit.