I want to circle the cell as shown in image. How do I do this inside a beamer frame?

I followed [this similar question](https://tex.stackexchange.com/questions/311367/draw-circle-around-cells-in-table-and-use-pause-for-this-cells) but couldn't figure out how to make the circle bold and red.

```
\documentclass{beamer}

\usepackage{tikz}
\usetikzlibrary{fit,shapes.geometric}

\begin{document}
\begin{frame}{}
    \begin{table}
        \begin{tabular}{l | c | c | c | c }
            Competitor Name & Swim & Cycle & Run & Total \\
            \hline \hline
            John T & 13:04 & 24:15 & 18:34 & 55:53 \\ 
            Norman P & 8:00 & 22:45 & 23:02 & 53:47\\
            Alex K & 14:00 & 28:00 & n/a & n/a\\
            Sarah H & 9:22 & 21:10 & 24:03 & 54:35 
        \end{tabular}
        \caption{Triathlon results}
    \end{table}
\end{frame}
\end{document}

```

[![enter image description here](https://i.stack.imgur.com/xta5g.jpg)](https://i.stack.imgur.com/xta5g.jpg)