5.69 miles in 1:05:21 @ 11:29 pace and 152/170 bpm for 897 calories

One of the most important muscle groups for endurance athletes is the heart and lungs—the muscles that define aerobic capacity.  Simply put, aerobic capacity is your body’s ability to transport the necessary amount of oxygen to your muscles for them to operate efficiently for long periods of time.  Aerobic capacity is also called “base” for short and is often referred to as an endurance athlete’s “engine.”

The thing about growing your aerobic capacity, also called “base training,” is that unlike other sports which require high-intensity weightlifting or sprinting or other workouts, base training is a slow and grueling activity where you purposefully keep your heart rate low for extended periods of time.  Mark Allen, six-time Ironman World Champion in the 90’s, wrote a great article where he describes the base-training regimen he used at the start of each season: “During those first few months of training, I would literally have to walk up even the easy hills on my runs to keep my heart rate from going too high…”  That’s right, the Michael Jordan of triathlon walked up hills during run training for months at a time before going on to win one of the world’s toughest endurance races six times—including a five-peat!

What I’ve found is that base training requires a great deal of patience.  Why?  Most athletes love to train, and the natural inclination is to get out there after a day or two off and really push.  But if you want to go race an Olympic triathlon that requires you to exercise for three hours straight, or a half-Ironman for six hours, the last thing you need to do is train at top speed.  You must have the discipline to watch your heart rate and put in the miles, and you have to enjoy slow and steady progress.

Today, for me that meant running a bit over five miles at 11+ minute pace (very slow!) to keep my average heart rate under 160.  You’ll notice in my summary line at the top of each post I list two “bpm” (beats per minute) numbers—the first is my average heart rate and the second is my maximum heart rate for the session.  You’ll notice that the the slower I run, the lower my average heart rate.  I don’t stare at my watch the entire run so I don’t hit my exact heart rate target (today was a bit too slow for example) but I get close enough to train my base and hopefully grow my “engine” to where I can run longer and longer races.