Weight gain from riding indoors

this has got me slightly baffled, over the last winter season (i am in australia), i have shifted my training mix from ~ 50/50 indoors/outdoors to 90% indoors due to kids sports/work etc. I am running a relatively high training load following the high volume plan - which i have done for the last 3 seasons. My hours on the bike each week have dropped from 12 to 9 but my TSS has stayed relatively consistent down from ~ 600 - 700 /week to 550/600/week. My FTP has stayed the same as prior years around 305 but my weight has moved up by 5kg.

The weight gain is baffling me as i cannot shift it, my diet has stayed pretty consistent and i am using myfitness pal to track so i know my calories are ok. The main difference to prior years is i have cut out my junk miles but kept the quality high.

The only conclusion i can figure is the junk miles whilst dont add to meaniful fitness gains are useful in burning extra calories. I am interested to understand whether those folk in the northern hemisphere that take their training almost completely indoors experience similar issues.

Thanks for any thoughts

If you gained 11 lbs your calorie intake is too high. You can take the 11 lbs times 3500 divided by the number of weeks it took you to gain it. That would be your weekly caloric overage. Divide that by 7 to get it daily and adjust your calories by the week or the day accordingly.


Hate to break it to you, but when you say you’re tracking your calories and they are ok, you’re wrong. You say you’ve gone indoors due to kids/work etc, i suspect activity levels are also lower overall

Case solved.
That is not consistent, a 100TSS drop per week. Based on my FTP that is 1500kcals less and I have a lower FTP. Not done the maths but you might be looking at 1600 - 1800 calories less a week. If you are eating the same as before that is going to result in a gain of 0.5lbs per week.

For the reduction in calorie burn I’d agree. I don’t disbelieve the statement that calorie consumption hasn’t changed.

I don’t follow high volume plans, but all activities burn some calories, including junk miles.

My n=1 is that I naturally tend to consume less when training indoors - 1.5 - 2 hour indoor workouts I barely add anything to my normal diet, and often do them straight without a breakfast. Where as when I’m going on a club spin, it’s normally 4 plus hours - so there’s breakfast, carb mix, real food, coffee stop.

What targets are you using in My Fitness Pal? Tracking is one thing, but if you’re tracking over maintenance you’ll gain weight. I use a calculator (something akin to scoobys http://scoobysworkshop.com/calorie-calculator/ ) to work out my target calories. Actually did it up in a spreadsheet (I can share, but reluctant as I have zero qualifications and just experience to go on). Again this is purely N=1 of what has worked for me.

Also, age can effect metabolic rate, as can stress.

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Junk miles, even if you’re correct in identifying them as such, still burn calories, regardless of how effective they are in training your body.

So the weight gain isn’t from riding indoors, it’s from eating more than you are burning.

I’m baffled that you would be tracking your calories and yet not recognise being in a calorie surplus

I’m the opposite, consume much less outdoors and during the rest of the day.
Outdoors typically 3 - 5 hours and only have a banana, few gels (sometimes none) and a bar, and struggle to eat after. Also more of the day has been taken up so less time to eat.
Indoor only 1 - 3 hours still eat on 2 - 3 hr sessions, because the season are shorter have more time to eat the rest of the day. I am also more hungry as its shorter and more intense.

Anyway, the OP is burning significantly less calories per week so I’d bet that is the issue.

Thanks everyone, very helpful. Obviously calorie driven, the rest of my day is pretty sedate - desk job + drive to office so my burn rate is obviously lower than my fitness pal. I will try cutting my calories into a bigger deficiency plus try to squeeze some more z2. Really appreciate everyone’s comments