Weather:  Amazing!  Cool and dry, very little wind.  I launched just after 6:30.

Plan:

• 4 x 2500
• 5′ active rests
• rate target: 26
• pace target: 2:15

I am pretty darn happy with this workout.  I would have been happier if it was faster, but I executed this workout to the best of my ability.  No theatrics, no bailing out.

There was one weird thing with today’s workout.  I was seeing a persistent difference in pace between the speedcoach and the GPS.  Now, over a short span, I don’t expect them to read the same, but for basically the whole row downriver, I was seeing the GPS based numbers giving a pace 2 to 5 seconds faster than the impeller.  Must be flow, you might be thinking.  At least that was what I was thinking, but right now, there is essentially no flow.  The water level is so low that basically nothing is going over the dam.  And when I saw the same thing going up river, I decided that something was fishy with the speedcoach impeller.  Either the cal was off, or there was something fouling the impeller.

Here is a comparison of the paces for the four pieces.

GPS — Imp –> Delta
2:12.0 — 2:14.6 –> 2.6
2:14.9 — 2:17.4 –> 2.5
2:16.1 — 2:18.7 –> 2.6
2:16.7 — 2:19.5 –> 2.8

I saw nothing on the impeller when I pulled the boat, so I will do the comparison again tomorrow and update the cal if there is still a difference.

Here’s the (slow) speedcoach data.

For comparison, here are the first 3 intervals based on TCX data from RIM.  The pace data is a lot noisier, but the eyeball average is about 3 seconds faster.  I had a glitch with the phone and the data for the 4th interval ended up in a different file.

Here’s the TCX data for the fourth interval.

Here are the tabulated results.

TCX Data from RIM
|Start|Dist_|Time_|_Pace__|_SPM__|avg HR|DPS_|Remarks
|00019|01203|07:11|02:59.1| 18.7 | 117 |09.0|Warming up
|01250|02496|10:59|02:12.0| 26.2 | 159 |08.7|rep #1 – downstream
|03746|00474|04:59|05:15.4| 16.1 | 125 |05.9|rest
|04269|02498|11:14|02:14.9| 26.2 | 167 |08.5|rep #2 – upstream
|06767|00424|03:53|04:34.8| 19.9 | 135 |05.5|rest
|07219|02501|11:21|02:16.1| 26.2 | 170 |08.4|Rep #3 – downstream
|00020|00280|03:22|06:00.7| 13.1 | 128 |06.4|rest
|00300|02498|11:23|02:16.7| 26.5 | 170 |08.3|rep #4 – upstream
|02798|01492|09:50|03:17.7| 19.7 | 139 |07.7|cool down
|—–|09993|44:57|02:14.9| 26.3 | 167 |08.5|Main Set

Impeller Data from Speedcoach
Start_|_Dist_|_Split_|_Pace_|_Strks__|_Rate_|_DPS_|_AvgHR_|_Remarks
00020_|_1188_|_06:46_|_2:50.7_|_122___|_18.0_|_09.7_|_117___|_warmup
01220_|_2501_|_11:13_|_2:14.6_|_292___|_26.0_|_08.6_|_159___|_rep #1
03720_|_0389_|_02:59_|_3:49.8_|_052___|_17.4_|_07.5_|_126___|_rest
04093_|_2508_|_11:29_|_2:17.4_|_300___|_26.1_|_08.4_|_166___|_rep #2
06610_|_0299_|_02:15_|_3:45.9_|_039___|_17.3_|_07.7_|_128___|_rest
06900_|_2512_|_11:37_|_2:18.7_|_304___|_26.2_|_08.3_|_169___|_rep #3
09420_|_0302_|_02:35_|_4:17.0_|_039___|_15.1_|_07.7_|_134___|_rest
09700_|_2493_|_11:35_|_2:19.5_|_306___|_26.4_|_08.1_|_170___|_rep #4
12210_|_1364_|_08:20_|_3:03.2_|_166___|_19.9_|_08.2_|_136___|_cool down

Dist__|_Time__|_Pace___|_Strks_|_SPM__|_DPS__|_AvgHR_|_Remarks
01188_|_06:46_|_2:50.7_|_122___|_18.0_|_09.7_|_117___|_warmup
10014_|_45:54_|_2:17.5_|_1202___|_26.2_|_08.3_|_166___|_Main set

Tomorrow:  75′ Steady State, 20 spm, HR cap at 155.