Old teams in NBA

The team with the best record in the NBA right now is the San Antonio Spurs. One of the hottest teams in the NBA is the Boston Celtics. When the playoffs come I believe these two teams will not make it far because of how old they are. They will not be able to withstand a 7 games series with teams like the Heat or Bulls for the Celtics and the Thunder for the Spurs. In my opinion I think it is going to be the Heat vs the Thunder in the NBA finals.