that is correct
that is why triathletes and ironman training is considered so brutal. you have to be really good at swim, bike, and run.. you can't suck at 1 or 2 of them and do well
i will tell you this though, if you want to juggle both you will wear down your body before you know it. as someone who is unique (the only mod who can say this) who has switched from powerlifting, to bodybuilding, to endurance, back to powerlifting, to being a yoga person, to being a vegan, etc etc. you have to pick ONE THING and focus on it to be great. you cannot juggle all of the above, you will only drive your body into the dirt.
anyone who says I'm wrong on the above... well that is because you are young. when you get older the body starts breaking down. that is why you see pro athletes with offseasons, they don't play their sport all year lol. you play 4-5 months, then take a break during the offseason.
that is also why you don't see pro athletes playing multiple sports at the pro level. you do that shit in high school and maybe college if you are lucky.. but in the pros. maybe a handful of guys have even done that like Deion Sanders and he didn't ever take a beating in the NFL because he avoided contact. Bo Jackson also played 2 sports, and his career was cut super short due to injury (surprise)