And they have a high amount of triglycerides means our major source of fuel, our major source of ATP is our fatty acids. So these muscles use predominantly triglycerides to break down the fatty acids in aerobic respiration into ATP. So that also means that they have a low fatigue rate. That means we can use them for hours and hours before they actually run out of that fuel source. So we can continually use our fats as our major storage fuel to form ATP. And that's exactly why these are the muscles that are used when we carry out very long activities such as running a marathon.