Does the Sims weight affect their athletic ability?

[Alexandria_]

If I was to make a Sim as large as possible or completely lack muscle, would it have any effect on athletic ability?
Or is this just something that forms over time as they do athletic activities?

[RubyLovesSims]

To my knowledge, no.
It is purely cosmetic, but as you said, it changes over time, with weight decreasing and muscles increasing.
I'm not sure about muscle definition, however.
Hope this helps!

[Pam]

I don't think it really matters much.  It doesn't seem to make the athletic skill increase slower or anything.  However, as your Sim gains athletic skill, his body will change.  He'll lose weight if you put him on the treadmill and he'll become more muscular if you put him on the weight machine.

[Alexandria_]

I thought so too, but thank you for clarifying 

[Leto85]

EA made this like real life mostly, according to Pam's post. But in what condition you will start working out doesn't really matter. And that is actually a difference with real life. Fat people are mostly stronger than thin people, just because they already have a workout from taking their body weight with them all the time. They are quicker tired.
For thin people the opposite counts. The should be better with things that requires condition.
According to that: the muscle definition should only appear after doing a lot of training and having a particular diet what force you to eat low fat food for six times a day and sleep well.
But I haven't see that in The Sims so what the muscle definition really affects exactly I'm not sure.