My goal in paddling isn’t about speed as much as a ficus on efficiency and physical conditioning. Training for competition is entirely different. At the end of a training session or a race, your energy should be completely spent, and that is the only way to know you put out as close to 100% as possible.
My numbers might be wrong, but I found through experimentation that over an 8.5 mile course, the best option is to remain aerobic through most of the course.
There is a certain built in error when using a GPS. Accuracy improves with the number of satellites used to fix your location, but that takes longer to calculate. There’s a tradeoff between fixing your location and calculating duration of the sample. In other words, a calculation based on 1/10th of a second is less accurate, but it gets a better snapshot of the speed. On the other hand, a 1 second sample is more accurate, but it essentially can only get an average of the speed over a second, so it misses the high and low during the sampling interval. Regardless of how the GPS samples the trip, the average speed is calculated using the distance between points and how long it takes to cover that distances. My deck mounted Gamin GPS is set at one sampling rate and the GeoTrack app is set to another rate. Additionally, I have the moving speed set to another rate, with one recording any movement, and the other device sensing only movement that is faster than one mph. Consequently, when I stop for a water break, one device reads as “Moving Time”, while the other device will show “Stop Time”. When I compare data at the end of a trip, the difference is under .1 mph between them.
I cross checked the distance/time by calculating distance using a nautical chart and the started/end time. Using the set straight line distance of 8.5 miles, I constructed a chart based on time to finish 8.5 miles over every minute from 135 minutes down to 100 minutes. I also have a chart for 8.36 miles and 8.6 miles. The difference if I recall is within around only .1 mph. My point is that the average speed calculations and GPS error rate is well within a tolerable range.
It’s important to realize that you have a greater impact on accuracy by paddling an inconsistent track. You also skew the moving time average sognificantly, based on how often you stop paddling but continue to glide until your GPS senses that your progress is sensed as “Stop Time”. The best way to get more consistent GPS results is to paddle more consistently.
When I compare boats or paddles, I make a stop ever 2.1 miles of 30 second duration for water That way, each trip has the same delay at the same point which divides my course into four equal legs. It helps that the tide datum point is at the peninsula that serves as the mid point with 2 legs on each side of the penninsula. That gives me two legs into conditions and two legs with conditions.
By using different approaches over the same course, I found that setting your metabolism to use energy aerobically is the best option. Based on your charts and paddling technique, I’m cetain you could add another .5 mph to your average speeds, if you balance your energy output.
I divided your chart into segments to highlight features that I noticed:
The gray line appears to be your GPS calculated average speed. That reflects the limit of your physical ability for that boat using current paddling technique. However, you still have room to tweek you output and increase efficiency. This may seem counter intuitive, but segment 1 shows you are exceeding the average speed in the first 3 miles. Then your average speed became inconsistent for 3/4 mile, and you returned to consistent speeds for a mile, before it again became inconsistent. Without understanding the conditions, I believe you were using glycogen in your arm and shoulder muscle groups for power, and you maintained that output for 3 full miles, before it appears that you started going in and out of anerobic output. Then you appeared to recovered and resumed consistent speed for a mile. Notice the change at the beginning of segment 4. Your power builds slightly in the first line, then the next two inclined lines show a steeper output and sharper drops. As you enter segment 5, that is where you show inconsistent power (unless you actually encountered harsher conditions). To fully understand the charts, consider how you felt in segment 2, 4, and 5. Why did you paddle/stop, paddle/stop? Were you facing harsher conditions or did you feel you were running out of energy. In segment 4, your speeds became more eradict. Then by segment 5, your ability to control speed was compromised.
You may want to try a different strategy. Since you have a limited supply of glycogen stored in your muscle groups, you can modify your approach without paddling harder. Noticing that your speeds were abive the grey line for the first three miles, below for for 3/4 mile, then above for a mile, then above and below for the last segment.
Since it takes about 20 to 30 minutes to kick start the aerobic process, try paddling at around 4.6 mph for the first two miles. That’s where you body clicks into aerobic mode. Hopefully, after 20 to 30 minutes, you’ll feel a surge of energy that’ll increase your speed by .2 to .4 mph. Keep that level of effort and avoid the urge to hit max spikes. Your cruising speed is easy 4.8 mph. Your goal should be managing 4.8 mph with a solid flat line on the graph through the duration of the trip. The faster your speed, the greater the resistance as you approach hull speed. Avoid speed spikes for two reasons: primarily, higher speed increases energy needs exponentiall, and higher speeds push your energy use into anerobic, which depletes oxygen and builds carbon dioxide in your blood stream.
Also consider lowering you paddling angle to reduce the transition distance between the exit and the catch. If your paddle feels too long for high angle (your blade for the next power cycle looks like it’s about 5 to 6 feet in the air away from the catch. A lower angle will put the blade closer to the water following the exit. The longer your paddle stays in the water, the more control you’ll have. Low angle also makes it easier for core rotation. The paddler’s box reduces stress on the shoulders, and a wider grip allows you to open your chest to favolitate breathing and remain in an aerobic phase. Your chart appears to show that you still had anerobic energy left at the end, because there are higher spikes than drops above the gray average speed line.
I may be wrong, but that is how I interpret your charts. If I’m correct in how I’m reading your charts, you are a stronger paddler than me. The recommendations I offered is how I improved my paddling average speeds without increasing power. Match you power to the paddle. If you feel cavitation, slippage, bubbles, oscillation or flutter in the paddle, you’re simply overpowering the paddle. Match your stroke to be only slightly faster than the speed of the boat. The paddle locks in the water, and the boat moves.
