• 27th July 2008 - By adventuresofgreg
    This is rather encouraging.

    I have analyzed and calculated and ran numbers in every combination and permutation regarding my chances to break Carter Johnson’s 242 km surfski 24 hour distance record. So far, to be brutal honest with you, I have not been totally convinced that I can do it. Carter is a formidable opponent and it is very difficult to beat the simple efficiency of a Surfski kayak and a paddle.

    Is my boat fast enough? Am I physically capable? Both really important questions, and both difficult to answer independently.

    Typical afternoon thunder boomers rolling in

    However, I found a way to directly compare man and machine. I found a YouTube video of Carter doing a 4 minute, 11 second thousand meter sprint in the same Surfski kayak that he used to set the 24 hour HPB distance record. I figured that if my fitness and my boat were both up to the challenge, I should also be able to complete a 1000 meter sprint in about the same time. And I did – 4 minutes, 11 seconds exactly.

    Below are the two YouTube videos – the top one showing Carter finishing his 4:11 sprint in his Surfski kayak and below that, me finishing my 4:11 sprint in Critical Power 2 human powered boat.



    I haven’t been training these short bursts, so my sprint interval power is probably down from what it used to be, but I was able to complete a few very painful 1000 meter intervals between 4:11 and 4:16. My interval was also interrupted by some waves from the SS Moyie paddle boat, and my prop striking the hull near the end of the interval when I was pushing out over 400 watts to finish. I am certain that I could shave at least 11 seconds off with some additional training – which would probably be good for me anyhow.

    I think this is a fair comparison and at the very least, it provides me with some level of confidence that I should be able to go at least 242 km in 24 hours with the assumption that my long distance endurance is at least equal to Carters.

    I have postponed the 24 hour record attempt until later in August to allow me more time to find a lake and get organized. We’re off to our cabin in Whitefish, MT this week and I am planning for some epic long training days on Whitefish Lake and maybe even Flathead lake with CP2.

    I just had an email conversation with Jeff Potter about what exactly we are hoping to prove to the world by beating a simple kayak with a complicated pedal and propeller powered boat. Jeff really makes me think about the bigger picture. I get so immersed in my challenge that I sometimes lose site of why any of it matters at all.

    If the record is a vast improvement over the kayak, then we could certainly state that our system is simply a better way of travelling on water by human power. It’s not that simple, and I really doubt that if I break the record, it would be by a substantial amount – however, 1 km over the current record in my books at this point *IS* substantial! A kayak is simple, light weight, and inexpensive. It can be dragged up a beach and generally weeds don’t effect it’s forward progress much. There isn’t much to break on it and you can paddle in shallow water because the draft is so small. The pedal powered boat is none of the above.

    A pedal powered boat does have it’s merits though – The advantages might be equal efficiency to a surfski – but I would say more comfortable to more people for longer distances than paddling. It also frees up the arms for fishing, or reading, or whatever. Most of the rowers tell me they would kill to be able to use their hands and arms during a long rowing journey.

    The technology we develop in pedal powered boats, however, has far greater importance than for what Joe Sixpak wants to tool around in on the weekend. Because we are developing a means to power a boat (or a road vehicle for that matter) that does not rely on large oars or paddles extending from the hull, we have a way to make our boats more aerodynamic for wind and weather sheltering for the rider(s). On long journeys, this is substantial (as PedalTheOcean hopes to prove).

    For the advancement of energy efficient water transportation, what we are developing with our pedal powered boats is DIRECTLY APPLICABLE to that end – whereas, paddle powered boats are not (I doubt anyone would be interested in pursuing a solar powered rowing boat). An adequate solar panel on CP2 would probably be the most energy efficient boat on the planet. I’m not sure how you could use a solar panel on a Surfski.

    I’ve said this before – Human power is about the pursuit of doing more with less rather than our current way of always trying to do more with more. Someone calculated that a gas engine in Critical Power would demonstrate fuel efficiency of over 10,000 miles per gallon.

    I would like to extend a HUGE congratulations to Carter Johnson who recently won the men’s solo division of the Missouri 340 kayak river race. Carter finished the race in 37 hours, 46 minutes. Johnson’s time is record-setting for this race, now in its third year. He finished more than eight hours faster than the winner in the men’s solo division last year. WOW!

    Carter Johnson during the 2007 Texas Water Safarai
    Image courtesy of FitToPaddle.com

  • 18 Comments to “1000 meter sprints”

    • Scott Ennis on July 28, 2008


      You may have addressed this before, so just point me to a previous answer if you have, but Carter is paddling, you are pedaling . . . wouldn't you get more power with a system that took advantage of both upper and lower body muscle groups?



    • "the Dude" on July 28, 2008

      OT: HPV boats

      human = boat, swim & backfloat
      log/surfboard paddled hand/feet
      dugout/raft with push pole
      dugout with wooden paddle/s
      ribbed skin/bark boat paddled
      plank boat with paddles
      plank boat with oars
      scull with oars
      pedal powered scull

      'Efficiency' depends on the metric used, the most efficient might be a swimmer, since no complex machinery involved, no time spent in design and construction, no cost, but this requires the local environment is perfect, warm water, no wave/shark

      If regardless of materials, time & $ spent, then efficiency is measured in other ways.


    • Adventures of Greg on July 28, 2008

      dude: When I speak of efficiency, I'm speaking of speed (on water) vs. energy consumed over long distances. Swimming is VERY inefficient. Rowing a skull for 2000 meters is very efficient, paddling a kayak for 24 hours is very efficient. Rowing an ocean row boat into a headwind isn't very efficient.

      Scott: no – You would get more instantaneous power (maybe) for a sprint, but over long distances just adding more muscles to the whole system doesn't improve physiological performance at all. there have been many studies. Over long distances the arms are about as efficient as the legs (if properly trained).

    • hyz on July 29, 2008

      This is a nice comparison of your boat and a kayak. How can you compare a Hobie Kayak with this?


    • Adventures of Greg on July 29, 2008

      Henk: This all-out 1000 meter time trial would not be a fair method of comparing different boats using the same rider because you would have various levels of training for each different method of propulsion. A Hobie Mirage drive is a different pedal action that my boat, so I doubt that I would be able to maintain the same power level for 4 minutes that I can with roundy, roundy pedals.

      It would work better If you used two different riders – each trained for their specific boat, but you would never know for sure if one rider was fitter than the other. The only really fair way to do it is with some kind of power meter on the drive.

    • Frank Eeckman on July 29, 2008

      Any prolonged effort is limited by cardiovascular potential. The heart delivers the oxygen you need to burn the fuel. (Oxygen delivery is more limiting than fuel delivery)

      In normal humans, lung capacity far exceeds what the heart can pump. Similarly, for any gross body movement, you can build muscle far in excess of what you can perfuse simultaneously.

      In normal healthy humans, cardiac output (stroke volume times bpm) is the true obstacle in all cases.

      Muscle efficiency is close to that of the best built human engines (i.e. about 25-30%).

    • Hannah Zimmerman on July 30, 2008

      Cool post! You may be interested in a story in the Pitch about the Missouri 340 race. Here is a link if you want to check it out..http://www.pitch.com.

    • Certifiable on July 30, 2008

      Greg stated previously that "Over long distances the arms are about as efficient as the legs (if properly trained)." I am not saying this is wrong on all counts, but it has never really made sense to me.

      We evolved as land animals with clearly bigger, thicker, longer limbs on our lower half than the limbs (arms) on our upper half for the express purpose of being able to carry our body weight over long distances and periods. Our arms were designed for grasping, eating, maybe occasionally hanging, but not for the heavy duty tasks our legs perform every day. How is it that our physiologically better designed for greater loads over long distance legs would ever have any competition from our relatively puny arms or even upper body? The lower body has greater muscle mass and better circulatory service than the upper body. Does it make sense that Carter's superbly trained upper body should be just as powerful as Greg's probably equally trained lower body? I don't think so at all. This is why in my mind, pedal boats should always BLOW AWAY paddle boats assuming relatively equal lengths, widths and weights.

      I think Greg is doing a GREAT job in his design and training efforts to beat Carter's record. I find very little wrong with what he is doing. Greg's CP2 is longer by 3 feet, narrower by some 7 inches, making it more of a surface tension/wave splitting needle than Carter's Huki kayak. CP2 weighs maybe 15 lbs. more, might have more wetted surface due to its pontoons, prop, shaft and larger rudder.

      Yet in my mind, Greg's pretty ripped lower body (butt, hips, legs) should CREAM Carter's impressive upper body (lats, trapezius, back, chest, shoulders, arms) on just about any rotary power test you might devise. Couple that superior lower body power to the constant, better water gripping traction of a propeller, and you should have an UNBEATABLE combination. A kayak has inferior upper body power coupled to an intermittent/pulsing, water slipping paddle that is usually at an angle to the water surface and the kayak's forward motion.

      Why shouldn't pedal craft be a quantum leap above in an endurance test like the 24 hour record? Why do well designed pedal boats fail to convert their superior lower body power into smashing records established by the inferior upper body power of the kayaks? This is the question that makes me crazy or … certifiable.

    • nemo on July 31, 2008

      To certifiable: muscle is not the issue, cardiac output is.

    • Jarl on July 31, 2008

      The Hobie kayaks with mirage drive are getting pretty decent speeds even with the heavy and slow hulls and often pretty unfit riders (from what i've seen at the hobie forum), would be interesting to see the performance of an evolved "super-mirage" drive, placed in a slim and efficent kayak hull with a fit rider.

    • Certifiable on July 31, 2008

      To fhe:
      If "muscle is not the issue, cardiac output is.", kindly elaborate on what you mean within the context of arm power versus leg power. I have not discounted cardiac output as a factor. I have wondered on this forum how an arm powered Huki kayak is proving to be so difficult to beat by even a superbly designed leg powered boat like CP2 given the obvious power advantage of legs over arms.

      How would you explain a leg powered bike ALWAYS beating an arm powered one, whether they are powered by specialized athletes or weekend warriors? How would you explain the over 2-to-1 advantage of a tandem Hobie kayak paddled by two good athletes being towed backwards by the leg powered flapping fin Mirage pedaled by the pasty faced designer? This can be seen at the Hobie Mirage website at:

      I still haven't heard of any superbly trained, even legless, hand standing athletes beating any weekend warriors in a race on flat ground or up stairs. 😉 Go to any gym and ask novice and bodybuilder alike if their arms can push or even pull as much weight as their legs, whether it is a maximal or endurance type effort. I think you will find that their cardiac output had little to do with their arm-versus-leg power comparison. Regardless of cardiac output, the lower body has larger arteries and veins supplying more oxygen to larger muscles giving an obvious short or long term power advantage over arms.

      Given leg power's superiority, why is Greg finding Carter's arm powered 24 hour record so hard to beat?

    • nemo on August 1, 2008

      Over short distances total power matters and that means muscle mass dominates. Total power includes anaerobic power production. The shorter the event is, the closer your heart can go to its maximal rate.

      In a 100m sprint for example, cardiac output does not matter at all and the whole event is anaerobic. You don't need to breathe. You also do not need to worry about skin perfusion to sweat, gut perfusion to digest, etc. etc.

      So, yes in any short event the large mass (i.e. legs) will win every time.

      Over longer distances, cardiac output is what limits performance and since prolonged maximal cardiac output is so much lower than what a large muscle mass can put out, it becomes the limiting factor. In a longer event you need to aerobic. You also need to perfuse skin to cool, gut to digest, kidneys to control fluid balance, etc. etc.

      The chronic cardiac limit is far below the difference between upper body and lower body muscle mass so that difference becomes irrelevant. The picture is totally dominated by cardiac potential.

    • "the Dude" on August 1, 2008

      Flippers are more fuel/oxygen efficient than propellers.

      Paddling kayaks and rowing sculls are more efficient than any propeller.

      Propellers afford greater simplicity and speed range than flippers, not so helpful to an HPV watercraft.

      Sea lions, fur seals, penguins, cormorants use (front) flipper power, other marine animals generally use tail fin/fluke and/or rear legs.

    • Anonymous on August 2, 2008

      If nature had a continuously rotating shaft in its arsenal then we would see water animals evolving propellers as they are more efficient than flapping devices for propulsion.

      So in this regard man has outdone evolution. If flappers were better we would see flapping wings on aircraft as manufacturers search out ever aspect that has an efficiency gain.

      Rick W

    • Frank Eeckman on August 3, 2008

      check this out.

      Nature has rotating shafts.

    • "the Dude" on August 3, 2008

      Rotating propellers are far more power-efficient than flapping, however they always produce high drag, whereas efficient flippers can be extremely low drag, depending on design and use.

      It's the continuous drag in water I was referring to in my last note.

    • Certifiable on August 5, 2008

      I am confused. Are you agreeing that propellers are a better way to transmit power, get traction in the water or not? Propellers are referred to as "lift" devices because they use rotating wings to screw/lift through the water, while paddles are "drag" devices because they rely mostly on drag to grip the water. If drag were worse on a propeller, Rick is correct in pointing out that aircraft designers would have gone the way of flapping wings, not propellers.

      To quote Wikipedia at:
      "In 1848 the British Admiralty held a tug of war contest between a propeller driven ship, Rattler, and a paddle wheel ship, Alecto. Rattler won, towing Alecto astern at 2.8 knots (5 km/h), but it was not until the early 20th century paddle propelled vessels were entirely superseded. The screw propeller replaced the paddles owing to its greater efficiency, compactness, less complex power transmission system, and reduced susceptibility to damage (especially in battle)."

      Nice try on the "nature has rotating shafts" reference but I believe that Rick was refering to animals visible with the naked eye, not nanoscale organisms where the laws of physics behave quite differently enabling a tiny insect to walk on water, but not a human. The bacteria use filaments, not propellers (rotating wings) that wind their way through the water much as a snake winds its way through sand or a corkscrew moves through a bottle cork. This is possible because at this nanoscale, water is probably more like jello or sand than the liquid we experience at our size scale.

      It would be impossible for nature to reproduce a rotating shaft on our size scale because no skeletal, muscular, vascular or nervous system could rotate continuously while still being attached. Flapping fins are doable in nature, they work very well, but propellers still reign supreme whether in water or air.

      FHE (or is it Frank also?):
      I think I see your point about cardiac output being the limiting factor in well trained athletes when comparing leg to arm power. But I would argue that most of us weekend warriors would do better with leg power than arm power, given that our legs are so much better trained through constant walking and carrying our weight around, versus arms that move much lighter objects and stuff food in our mouths.

    • "the Dude" on August 6, 2008

      It really depends on the definition of 'efficiency' used. A prop is a compromise, with its continuous rotation it fits well with lower body rotary action, while the upper body fits well with submerged-down-stroke emerged-up-stroke paddling. The pedal-to-prop system should do better on longer courses due to consistency (less room for errors and non-beneficial energy expenditure).

      The prop however always has drag at all times, while the paddle has drag only on the down stroke, since it travels through air on the upstroke (discounting the tiny resistance of a flat paddle moving forward in air). A penguin flipper travels through water on the upstroke so it produces more drag than a paddle, so it is closer to a prop performance.

      I don't know how close these are, they may be so close as to be over-ruled by other factors (comfort of stroke, posture, hull shape, depth of prop/paddle, waves…).

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