The study looked at 20 marathon runners with varying levels of fitness (based on their VO2 max). Those in the less fit group showed abnormal functioning in more than half of the 17 segments in the heart's left ventricle, unlike their fitter competitors. Other areas of the heart had to work harder to compensate. The good news is that the heart damage was not permanent. After only 3 months, the damage was no longer visible.
So in case you didn't know, don't try and run 26.2 miles without training properly!!
Weights45 minutes of light weight, high reps - worked shoulders, back, biceps and abs
Swim888 yards (1/2 mile) in 15:38
After a quick warm-up, I did a half mile at a pace slightly faster than the pace I swim during a half-Ironman (1.2 mile swim). Felt pretty good the whole time and tried to focus on hand entry and body rotation.
Bike5 minute warm-up, 45 minute Spin Class and then a 5 minute cool-down
I really pushed hard the entire class. This was just a steady effort mixing in some hills, but no intervals. My heart rate was pretty high the entire time as you can see from the chart below (almost half the time was spent in Zone 4).
Weights30 minutes of legs with some stretching mixed in