Viewing the phrase in isolation, this response is logically correct, but it's more interesting to view this in the context of the rest of the author's arguments.
If you're consistent with physical exercise by resisting when you feel like skipping a workout, you'll have more strength, endurance, and freedom of movement when you become much older. And if you're consistent with improving at your career skills, you'll have more career opportunities in the future. Therefore, even if you may seem less free by avoiding unhealthy food or watching too much television, you're setting yourself up for more opportunities in the long-term.
I personally do agree that you can be disciplined toward the wrong goals, though I also think it's more interesting to consider Willink's arguments as a whole, instead of focusing on a phrase in isolation.
If you're consistent with physical exercise by resisting when you feel like skipping a workout, you'll have more strength, endurance, and freedom of movement when you become much older. And if you're consistent with improving at your career skills, you'll have more career opportunities in the future. Therefore, even if you may seem less free by avoiding unhealthy food or watching too much television, you're setting yourself up for more opportunities in the long-term.
I personally do agree that you can be disciplined toward the wrong goals, though I also think it's more interesting to consider Willink's arguments as a whole, instead of focusing on a phrase in isolation.