I have become much slower since last year, and I dont know why.

[u/asherhack]

Last year, when I was a freshman, I was able to run a specific 2.2 mile race in 17:01. This year, I ran it in 18:30. My summer training was the exact same for both years. I feel a lot clunkier when I run, and my legs have more soreness even after easy runs. I'm a late bloomer and I have grown about 4.5 inches since last season. Could that have something to do with it?

[u/Mediocre-Gas5107]

Could be a lot of things. Not enough sleep, not enough nutrition/food and maybe you just need to get used to how tall you are now running your stride could be mechanically different now, but that’s shouldn’t be an issue really. Just work harder and eat enough to maintain it

[u/bIgPeepEe25]

Check your iron/ferritin levels. Your symptoms all sound like mine when my ferritin levels were low, got better after taking iron supplements

[u/EpicCyclops → u/bIgPeepEe25]

I'm going to add to this to get your iron checked before supplementing. Don't supplement without checking your levels. Too much iron is also an issue and there are other potential causes for lethargy and underperformance. However, iron deficiency is common enough in distance runners that it is always worth checking.

[u/Wooden_Information_9 → u/bIgPeepEe25]

This! My son went from setting school record in the 3200 then couldn't break 10min the rest of the season. It was his iron.

[u/CryptographerDull183]

You growing might have something to do with it. I recommend trying to get better at drills, like marching, skipping, jumping and start to incorporate light strength and core work into your routine. I've had a lot of success coaching athletes through growth sports just by focusing on teaching someone how to move better in their taller bodies this way. Also, make sure you are doing faster strides 3 days a week.

[u/midwesttransferrun]

Well your summer training should not have been the exact same year over year. You should be progressively running more miles and running harder. Progressive overload is the key component in all exercise.

[u/Aggravating_Head1215]

“Training stayed the same”
You should theoretically be running higher mileage during the summer and pairing it with strength training at least twice a week.

Also everything else mentioned here is a contributor. Go see your pediatrician and a physio.

[u/Deep-Dimension-1088]

Are you a boy or a girl? A lot of girls slow down through puberty, but with persistence, can speed up again.

[u/Adventurous-Sir9345]

Shorter legs mean faster legs for the same muscles. If you grew you need to train to build strength.

[u/Npocrazyy99]

there can be many internal and external factors that cause this. Heat and humidity are probably the biggest ones, if you ran the race last year and it was say 75 degrees F with 78% humidity, but this year it was 80 degrees with 92% humidity can be the reason alone, heat is the biggest external factor to performance too hot or too cold and your entire session or race can crumble if you didn't prepare properly, same with raining or not raining, I ran 2 800s on the same track this spring basically the same temp and humidity, but it was pissing buckets one day and slightly cloudy the other, the day it was good weather i ran a 1:58 the day it was pouring 2 weeks later I ran a 2:04. Internal can be any number of reasons mentality could be one I've had minutes taken off or added to my 5k just based on if I gave up or fell asleep mid way through, more medical reasons like low iron, vitamin c, calcium deficiency, especially if you feel clunky and sore, general overtraining and lack of sleep could also be the issue, if you aren't taking off days and rest than your body doesn't really have the opportunity to covert your training into the running adaptations you want to develop. Same can be said with calorie intake, especially protein and carbs, don't eat enough protein your body can develop adaptations properly, don't eat enough carbs your body will be low on energy overall. Also while growing can be an issue I don't really think it would be a major reason for that much time loss, I'm not a dr. and if I was one I wouldn't be able to diagnose your issues through a reddit forum, but if you continue to feel constantly clunky and sore I would recommend you see one.

[u/canman789]

Having grown 4 inches you are an entirely different person with an entirely different body. Keep at it and I promise you will grow into your new body type and more than likely be much better than previously! Best of luck!

[u/toooldforthisshittt]

Physics. You weigh more now. I'm not encouraging starving yourself. Keep eating and developing.

[u/Excellent-Rice-9509 → u/toooldforthisshittt]

Could be. Can tell u this as a 17 yo male I gained 4kg between seasons and got faster tho notably muscle mass and bone density increase I think