Originally Posted by musicmaster

To start, I'm a marathon runner and have been running 70+ mile weeks for over 10 years. I recently moved to CO, I've been biking 1-2x per week as cross training.

As I have years of aerobic base training from running, I'm finding it hard to really judge effort while cycling via heart rate as my HR stays pretty low the entire time. Also, the consistent rolling hills or mountain climbs here in CO seem to make it difficult to judge.

I was thinking of purchasing on the crank-based power meters (The 4iiii) for around $350.

For those who have them, do you find they are worth the cost?

I'll either be doing an Oly Distance or Half Ironman next spring.

I'm trying to base my current rides off of PE, which isn't bad on the flat sections. Rolling hills though, I seem to overdo it early on, and on the long climbs (4-5 miles at 5-7%) I just bike and it's hard to tell how hard I'm going and my only performance indicator is to compare times from the same climb each time to see if there's improvement.

My thought behind a PM is that I'd be able to have a consistent workout regardless of wind/elevation/climb. If I know my workout level is around 170W of something, I'd be able keep that specific wattage for my intervals or "tempo" on the bike without being concerned about the route I take.

Heart rate training has been a bit of a hit or miss. Because of my huge aerobic base from running, it takes a lot to get my HR up. I often find my legs give out well before i'm anywhere near my running HR, thus I was thinking a power meter would be a better gauge of how I'm training and to base workout on.