Small Signs of Progress: Heartrate Changes

Since I gave myself shin-splints a few weeks ago, I've been limiting myself to walking daily. No running. I worried for a while that I would feel like I was stuck because I wasn't progressing to running but I think that was a false concern.

I've been able to walk faster from week to week and I've settled for walking for an hour, most days (a few days I've been the butt of Mother Nature's joke on females and just couldn't go far or fast - but I still went). I started out with under three miles in an hour, now I'm up to over 3.1.

I've also been paying attention to my heartrate and using it to help judge how fast I should be walking. I like my heartrate to be in the 120s during the bulk of my walk. When I first started out, 2.8 mph would have my heartrate in the high 120s easily. And if I slowed down, my heartrate would take several minutes to slow to the 110s.

Today I noticed that walking at 3.4 mph had my heartrate in the low to mid-120s and when I slowed down, it took under a minute for my heartrate to drop.

That's progress that may not show on a scale or as running, but my body is slowly adjusting and getting healthier.!

Don't Rely on Treadmill Calibration!

I've already confessed to being both a geek and a data junkie, so this post may not come as a surprise to any of the (no) people reading this blog. Once I had my new Garmin in hand and started using it, I started to see interesting discrepancies between what the treadmill's display was telling me and what the Garmin was telling me.

Now, I would expect that if it were a problem with the Garmin or its footpod, I'd see the same or very similar discrepancies all the time. But that's not what I'm seeing.

A few days ago, I used the third treadmill from the end at my gym and noticed that 3mph seemed exceptionally slow. After a bit, I glanced at the Garmin and it said that I was really walking at 2.8mph. hmmm.

Today I used the fifth treadmill from the end to see what happened. The treadmill's stated speed agreed with the Garmin's reading so it was probably reasonably close. But the problem came in mileage....

I walked for 2 min at 2.5 mph (a warm-up and a cool-down minute)
Then I walked for 58 minutes at a 3.0 OR GREATER speed. I was watching my HR monitor and would go between 3.0 and 3.2, depending on what my HR was doing, mostly 3.1-3.2.

At the end of the hour total time, the treadmill told me I had walked a total of 2.75 miles.

Ummm.... that math does NOT work at all.

58/60 = .97 (the portion of an hour actually walked in full-on mode)
.97 * 3mph = 2.9 miles (minimum distance because I'd actually spent most of it at 3.1 to 3.2 mph).
1.0-.97 = .03 (the portion spent in warm-up/cool-down mode)
.03*2.5mph = .075 miles (distance walked in warm-up/cool-down)
2.9+.075 = 2.975 miles

2.975 is the MINIMUM I walked. This is a difference of almost a quarter mile from what the treadmill told me. The difference is greater if I take 3.1 mph as an average and do the same calculation.

Seriously - walking 2 minutes short of an hour at a 3mph pace should give me just shourt of 3 miles, no? Not 2.75.....

So, in light of all the variances, I'm going to stick with the Garmin's variances since they should be consistent over time. I think my best bet is to walk for an hour and just see how far I go, since I know I can walk 5K in an hour at a very doable pace.

So - this is my data geek warning to never take what the display on any exercise machine tells you as the truth. Calibration (or lack thereof) can play havoc with the stated values.

Today's Walk - Sammamish River Trail (WA)

Today, despite it being my allowed "day off" of exercise, I decided I wanted to take advantage of the nice weather and walk along the Sammamish River Trail. I live in Western Washington state and we're very lucky in the number of trails, paths, parks, etc we have. Many of these are multi-use trails where bikers, walkers, runners, skaters, etc. all share the trail. For the most part, this works really well and the vast majority of people follow the basic rules and are nice to each other.

The Sammamish River Trail is 10.9 miles in full, all paved. I love the river and all the plant, insect and wildlife I get to see. In fact, I meander along it with my camera quite a bit. Today was obviously Canada Goose day as a lot of them were bobbing in the river, looking for snacks.

I enjoyed my walk and put a link to the map generated by my Garmin Forerunner during the walk at the top of this post. See - DATA!

I slathered on a lot of sunscreen, filled the smaller Camelbak with water, brought my good sunglasses and set off in my VFF.

Things I'll do differently next time:

• Burp the Camelbak. The sloshing was a bit annoying.
• Put ice in the Camelbak (we don't use much ice at my house so rarely have any - might have to stop somewhere). The water got pretty warm after a bit.
• Take chapstick. The sunscreen did well on most of my skin but my lips suffered a bit.
• Go earlier in the day. It gets a bit crowded at noonish on a weekend.
• Remember my iPod.

What a lovely day for a walk.

Oh - and I realized I got 5K done in under an hour. Woohoo!