Science of Paddling Fitness

The Science of Paddling Fitness

Many paddlers have discovered the undeniable benefits of a structured science-based training regimen. It works and works well. It’s what Olympians and elite athletes around the world do to train, and it makes sense that the same principles apply to those of us with more modest fitness and competitive goals.

However, as paddlers, we are not all the same. We are all unique in our body composition, fitness levels, and individual exercise capacity. Therefore, we must tailor our structured works to those unique attributes to get the most out of them. Most structured training programs do this by scaling the intensity of exercise into zones based on either perceived exertion or heart rate zones that are based on our age, or historical data. Alternatively, we can undergo medical testing to determine actual zones based on medical indicators. Using these zones, we can then customize workouts to our individual needs and characteristics.

Training Zones

For me, understanding the science of paddling fitness is super important, but how do we know if our zones are optimized or even correct? Perceived effort is subjective and relies on how we feel or physical indicators. If we use the aging method, we subtract our age from 220 to obtain a theoretical maximum heart rate. From there we use percentages of that maximum heart rate to define our workout zones. We can also use historical data captured from a wearable device on our maximum heart rate while exercising to determine the max heart rate we have to achieve while exercising. Zones are then derived using the same percentages of maximum heart rate as in the aging method.

The variability in the historical data method lies within the accuracy of the device that was used to capture the data combined with conditions in which the data was captured. Was the max heart rate data representative of maximum effort?

There are a lot of variables at play in all three methods of determining your workout zones.  With that said, is it close enough to get results? Almost certainly the answer is yes, but the question remains on whether or not you are getting everything out of your workouts that you possibly could. I’ve personally invested and continue to invest quite a bit of money on training and training programs, and I want to make sure I’m getting the maximum return on my investment.

The Medical Option

To put these questions to rest, I recently paid a visit to the Henry Ford Human Performance Clinic in Detroit Michigan for a comprehensive fitness evaluation.  It was time for me to put science-based training to the test. The clinic is attached to the Detroit Pistons Performance Center which serves as the headquarters and training facility for the team and provides medical care for both the Pistons and the Lions.

It’s a $300 test, not covered by medical insurance, but billed as preventative cardiology. Not cheap by means, but comprehensive, the test included:

  • Cardiovascular screening examination
  • Maximal exercise test with an electrocardiogram to monitor your heart’s activity
    • Maximum aerobic capacity (VO2max)
    • Anaerobic threshold
  • Body composition analysis
    • Resting metabolic rate
    • Body fat percentage
    • Lean body mass
  • Consultation with a clinical exercise physiologist
    • Training recommendations and heart rate training zones based on test results
    • Goal specific counseling

The Test

All told, I spent about 3.5 hours at the clinic, which didn’t include the extensive exercise history I had to complete beforehand. The first step in the evaluation was a trip to the Bod Pod, which looks like a giant egg. The Bod Pod is an air displacement plethysmograph which uses whole-body densitometry to determine body composition (body fat and fat-free mass). Basically, you are sealed in the pod and they pump air in and measure the volume of your body, composition, and lung volume. After the machine was set up and calibrated, the test only took a couple of minutes. Physically I felt a little air pressure change in my ears. Mentally, it was slightly claustrophobic, and I had to get over being mostly naked in front of a stranger, which for me is the stuff of nightmares.

From there we moved into the lab for the exercise test. There are two modes of exercise to choose from, running or cycling. As a cyclist, I chose the latter. In either case, the lab is equipped with a highly calibrated, computer-controlled exercise bike, or treadmill. It’s important to note that the results between running and cycling would be and are expected to be significantly different. Truth is that every activity or sport has a variable VO2 Max and unfortunately a paddling ergometer was not available for the test.

For the test, I was fully outfitted with EKG leads and a mask that covered my nose and mouth with a tube to measure my airflow. The test was a ramp test where the bike added 20 watts of resistance per minute at any even rate until failure.

For calibration purposes, I wore my Garmin Forerunner 935 but had to use the wrist-based heart rate monitor as there were EKG leads where the chest strap would have been. I’m happy to report that the HR data from my Garmin was dead-on accurate to the EKG data at all phases of the test.

My Results

My cycling VO2 max for the test was 36.37 mL/kg/min at a max heart rate of 163bpm and 302 watts of output power. For comparison purposes, my Garmin reported a VO2 max of 44 at 163bpm during the same activity, a significant difference.

My Ventilatory Threshold (VT) was measured at 59.57% at 117bpm. VT is similar to the lactate threshold (LT) which is measured through blood testing during exercise. I did not have the blood testing done, but the VT provides some insight into LT. VT is measured through changes in CO2 expiration and O2 consumption, along with breathing rate and volume.  Both VT and LT are able to identify when the body is accelerating towards fatigue. VT, AT and LT often times are used synonymously and often occur around the same level of workload/heart rate. It was explained to me that it’s easier to improve VT than your overall VO2max. Improving your VT (without improving your VO2max) will make me a fitter and better performing athlete. As a result, I will be able to perform at a higher percentage of my VO2max and not fatigue as quickly.

My Zones

As a result of the test, the exercise physiologist who conducted the test set my cycling target heart rate zones as follows. I have included my original heart rate zones set by age/gender guidelines as a comparative reference:

Zone Medical-Based Age-Based
Zone 1: Easy 106-129 125-133
Zone 2: Aerobic 130-139 134-142
Zone 3: VT Threshold 140-150 143-150
Zone 4: VO2 Max Intervals 152-163 151-172
Zone 5: Speed Intervals 163 173


For the most part, the changes in my zones are subtle and generally within 5bpm. Out of curiosity, I went into Garmin Connect and filtered cycling activities from this year to look at recorded max heart rate data. I found several incidents where I have recorded heart rates above 170, but they are very brief spikes that would indicate to me that those are data anomalies more than a true measure of max heart rate. The vast majority of my workouts were in the 160-167max bpm range.

The body composition results were surprising. Over the last 18 months, I’ve lost around 50 pounds. I always assumed I still had a ways to go. I weighed in heavier than usual the morning of the test at 199 pounds which is considered clinically obese for a short 5’5” man. This put my BMI at 33.1. I would need to weigh 149 pounds to reach the top end of “normal”. I’m not skinny by any means, but it’s hard to picture myself 50 pounds lighter than I am now. The Bod Pod showed a 27.7% body fat with a lean mass of 144.1. If I was going by just BMI, I’d have less than 5% body fat at what it considers healthy. As it stands, I’d be happy to lose another 10-15 pounds and call it good. My resting Metabolic Rate is 1787 kcal/day.


While there was a significant difference between the VO2 Max results from the medical lab and Garmin, the training zones are actually very close. They were close using the age-based methodology and closer yet if I aggregate Max HR data from recent workout history.

While my test results are specific to cycling, going through this process has given me confidence in the accuracy of the Heart Rate data. I aggregated the Max Heart Rate data for my paddling activities for the last 6 months and have a high confidence level that my max paddling heart rate is 169. I reset my zones accordingly, again, that changes were very small.

So is medical testing worth it? Maybe. I think it depends on whether or not you feel right where your zones are set. The perceived effort index is a good test when your zones are calibrated correctly. There is also the question of whether you believe your fitness tracking device is accurate. The accuracy of the Garmin Forerunner 935 wrist sensor shocked me.

In general, any method of calibrating your training zones is probably close enough for most people. However, medical testing is the way to go If you’re stuck or looking to get every bit of return you can out of the time you spend working out.

Personally, it was worth it to finally be able to let go of the myth that I needed to be 150 pounds to be considered healthy. There is also value to being confident that you are doing the right things to achieve the results you want. Science-based training is an important key to growth and success as a paddler.