When the people on your team aren't performing up to the same level you're at, don't get angry at them. What you need to do is raise the bar.
What that means:
Your performance rises and acts as the standard everyone else must reach. You don't come down to the level of your team -- you make them rise to reach where you're at. This is much harder than it sounds. Humans are social creatures; there is only so long we can be around any influence and not be affected (or infected) by it. If you don't keep your mind strong, you will become part of that average in due time. Which is why the Circle of Five Friends philosophy is so true.
They say when you raise the bar, you lose the losers, and when you lower the bar you lose the winners. Meaning --
If the standards are too high for some people, they will try to get those standards lowered (which is what leaders, coaches and managers usually cave to). If you don't bend to that pressure though, the people who can't measure up will leave or be removed. You will cycle through a lot of employees/trainers/contractors to find the right ones this way.
When the standards are too low, you will attract more people, since most are average by definition. The problem is, lowering the bar is disrespectful to your people who can and want to do better -- and they will find somewhere else that actually challenges them. And you'll be stuck with a team or losers with low standards.

Over time, people will rise or fall based on what's expected of them. You can essentially control people's actions by where you set the bar.