This is a subject that we could spend HOURS talking about and there are countless ideas, concepts, and methodologies used to help with. In fact, a few months ago, Coach Cody and I went to an Aerobic Capacity Certification that was 8 hours on a Saturday and the content felt crammed even in that amount of time.
But, to keep my answer short enough to keep people’s interest I’m going to give three pieces to think about.
1. If you start a workout with good energy and then get too tired to move halfway in, you most likely aren’t doing a good job at pacing the workout to your current ability level. You’re expending too much energy at the beginning (as almost all athletes do, even most of the best in the world) and not properly pacing for your current ability level. So, my first piece of advice would be to think about the workout thoroughly before, come up with a gameplan and start slower than you think you need to and only increase pace as you feel strong and like you have more to give.
2. Even though most people hate it, I think that running is the best way to increase your endurance. First, everyone knows how to run and you can do it any time of day by just walking outside and going for it. Second, when you do it you’re required to support your own bodyweight at all times, so you’re being “punished” for weighing more, unlike the rower or the assault bike where it actually pays to be heavier. Third, you can increase your pace when you feel good, back off when you’re getting tired and still continue.
3. If you’re going to run, please DO NOT go outside and jog/walk a half marathon weekly and expect to get faster or improve your endurance or aerobic capacity. By running slow, but covering distance, all your teaching your body to do is to get slower and work with a low heart rate, anyone can do that. And, without trying to offend anyone, running a 2 hour half marathon does not impress me at all. Running (8) 400m sprints, which is only 2 miles of running is far more impressive and will be much more effective because of the intensity involved. So, the lesson here is, as always, intensity is king when you’re trying to drive physical adaptation.