Unbroken on the swings, and a steady pace on the bike. As fast of runs as you can manage, knowing you'll recover on the sit-ups. Today is all about challenging that tempo/pace. So when your heart rate is getting higher and your muscles are fatiguing faster, remember this: if you can breathe, you can move. Yes it might be shallow breaths and it might be uncomfortable. Embrace the discomfort, know that it is necessary, and push through.