2-second power & 20-second power almost the same

Discussion in 'Power Training' started by bradg, Apr 3, 2013.

  1. bradg

    bradg New Member

    Joined:
    Apr 3, 2013
    Messages:
    37
    Likes Received:
    1
    I was testing my 30-second power output over the weekend, and repeatedly, I noticed in the Training Peaks analysis that my 2-second power was pretty close to my 20-second power: 970 watts vs 902 watts. I weigh 80kg. Is this a normal relationship between the two durations? I've been told it's "rare," but nothing beyond that. Was just curious. Thanks!
     
    Tags:


  2. daveryanwyoming

    daveryanwyoming Well-Known Member

    Joined:
    Oct 3, 2006
    Messages:
    3,857
    Likes Received:
    97
    Well it either means you've got fantastic fatigue resistance for very short hard efforts or more likely it means you've got good anaerobic capabilities but not so much in the neuromuscular department.

    Just taking a wild guess I'd wonder what your form and gearing choices as well as terrain choices for the really short sprint work. IOW, are you jumping after those short big power burst sprints in an appropriate gear or are you perhaps over geared and grinding up to speed? Is you body position while sprinting low and taut with firm but deeply flexed arms pulling hard on the bars while you pounce with everything into those first few pedal strokes? Are you spinning at 90 to 100 rpm BEFORE you jump during those short explosive sprints or perhaps geared up and slamming 70 to 80 rpm and then trying to explode into the sprint?

    IOW, I'd investigate short sprint technique. Maybe that's all dialed and you're jumping in good gearing at high speeds off of descents or off of leadouts and your upper body engagement is totally dialed but IME those are typical problems for folks that can go very hard but lack a ton of snap and peak power in their sprinting.

    As mentioned in another recent thread, long drag race sprints and short intense power/speed burst sprints are really different beasts and draw on somewhat different energy systems but both can be trained if you work on them. Sounds like your long creep sprint or drag race is pretty good but maybe some attention to your short intense sprint is in order. When in doubt sprint in easier gears till you get the peak power bit and instantaneous acceleration dialed in.

    Good luck,
    -Dave
     
  3. bgoetz

    bgoetz Member

    Joined:
    Nov 25, 2010
    Messages:
    816
    Likes Received:
    20
    I am going to say if you are hitting 900+ for 20 seconds, you most certainly have a lot more of a initial kick than 970, maybe you just have not seen it yet.
     
  4. bradg

    bradg New Member

    Joined:
    Apr 3, 2013
    Messages:
    37
    Likes Received:
    1
    Thanks for the insights! Forgot to mention, I'm using a wired powertap, on a Cervo 2.4. Hey, I got it for $175...to a degree you get what you pay for, but at this point I'd rather not drop the $2000 on a Quarq.

    While I don't believe that barbell strength immediately translates to power on the bike (at all), I'd be a little surprised if I was totally lacking in the neuromuscular department--I can squat almost 300 and deadlift well over 400. Power clean 215 pounds, broad jump of 9 ft and 30" vertical. Obviously, it's another matter when it comes to pedals, but the other physiological markers seem to indicate that the potential might be there?

    I did these in a 50/17, and at most on a 1-2% grade.

    My guess? There's a lack of snap. Any thoughts on improving that snap?
     
  5. acoggan

    acoggan Member

    Joined:
    Jul 4, 2003
    Messages:
    3,047
    Likes Received:
    9
    To answer your question directly: no, it isn't normal - in fact, on average (n = 50 or so, with a broad range of abilities and strengths/weaknesses) 20 s power is only 73% of 2 s power.

    Even my wife, who had an exceptionally-high functional work capacity compared to her maximal neuromuscular power, could only achieve 81%.

    Conversely, an individual with a very high maximal neuromuscular power but with only an average functional work capacity falls to 61%.
     
  6. RapDaddyo

    RapDaddyo Active Member

    Joined:
    May 17, 2005
    Messages:
    5,088
    Likes Received:
    41
    Did you actually do a 5sec max power test? If so, what was your test procedure and what was your initial cadence?
     
  7. danfoz

    danfoz Well-Known Member

    Joined:
    Apr 12, 2011
    Messages:
    2,432
    Likes Received:
    92
    Don't want to hijack this thread but what is the best strategy to test for 5-sec power? I.e. initial gearing (would it be the same as the gearing I'd end up in?), cadence, rolling start, gradient, etc. I'm sure it's somewhat specific to the individual but thinking there might be a way to maximise the result.
     
  8. bradg

    bradg New Member

    Joined:
    Apr 3, 2013
    Messages:
    37
    Likes Received:
    1
    Thanks, all. I had replied earlier but it's not yet posted--can't verify my account via my email for some reason, and new forum members have to await moderation on their posts. Fair enough.

    acoggan--I'm assuming you're Andy. Are you still at Wash U in St. Louis? I live over in Tower Grove and have consulted for Wash U's rowing team over the past couple years.

    I have not done a formal 5sec max power test. The highest I've ever seen on my Cervo (this is a wired powertap) was maybe 990. Maybe I just really lack top-end power. I find that a bit odd given my background in Olympic weightlifting and the fact that I routinely deadlift over 400#, but then again, it's not like barbell strength = bike strength.

    My cadence on the 30-sec test reached 141rpm @ 31.5mph. Started @ 7mph in 50/17, 35rpm and was at 118rpm about 5sec in.

    Is it possible this PowerTap is just off one way or the other?
     
  9. acoggan

    acoggan Member

    Joined:
    Jul 4, 2003
    Messages:
    3,047
    Likes Received:
    9
    As long as you can get up to, but not go way over, 120-130 (maybe 140, if you're a real fast-twitcher) rpm in just a handful of seconds, the gearing, gradient, etc., doesn't really matter.

    This blog entry (part of a series) might help explain why:

    http://www.trainingandracingwithapowermeter.com/2010/12/prediction-of-muscle-fiber-type-from_20.html
     
  10. RapDaddyo

    RapDaddyo Active Member

    Joined:
    May 17, 2005
    Messages:
    5,088
    Likes Received:
    41
    I'm sure there are multiple approaches to a 5s test, but here's what I do and why, First, I prefer a slight upgrade. Why? Because on the flat I might spin out my gear and I don't want to have to shift during a 5s effort. Second, I prefer to start the effort in a gear that will give me an initial cadence of about 100rpm. Why? Because from experimentation I know that my max power is produced between 100 and 150rpm and I want to give myself a headroom of about 50% increase in bike speed during the test. Third, I don't rock the frame from side to side too much, about 15 degrees to each side is about all. Why? Because I am basically just trying to get my weight over the downstroke pedal and to tilt the frame more than that is wasting energy. Finally, I try to rest for about 5mins before and after each effort (e.g., 100-150W).
     
  11. danfoz

    danfoz Well-Known Member

    Joined:
    Apr 12, 2011
    Messages:
    2,432
    Likes Received:
    92
    Thanks fellas.
     
  12. daveryanwyoming

    daveryanwyoming Well-Known Member

    Joined:
    Oct 3, 2006
    Messages:
    3,857
    Likes Received:
    97
    Good points above, but in terms of your initial gearing try to pick a gear where you're spinning at least 90 to 95 rpm BEFORE you jump up and sprint, IOW don't grind gears hoping for higher power. That and really jump on those initial pedal strokes with everything you've got instead of trying to ramp into the effort. Personally I get my best solo five second power numbers (that is without a leadout or motor to take me to speed) by finding a road that goes downhill for a while to get me up to speed and then flattens out or gently tips up during the actual sprint. Use the descent to get up to typical race speeds or higher without expending much energy then jump for all you're worth as it flattens out and drive it hard to your pre-selected finish line. If you're looking for a peak 5 second effort then try to time your jump so it takes about six to eight seconds of all out effort to cross your chosen finish line and wind like crazy all the way to the line.

    Also pay close attention to upper body position when you go after peak power sprints. It's not like climbing out of the saddle with a tall and extended upper body, it's low and crouched with all your energy coiled up and ready to pounce on the pedals instantly. A lot of good road riders sprint like they're climbing a hill out of the saddle and that's not likely to yield your best peak or 5 second power numbers. Pull those bars back towards your belly and jump on the pedals at speed to see big power numbers.

    -Dave
     
  13. bradg

    bradg New Member

    Joined:
    Apr 3, 2013
    Messages:
    37
    Likes Received:
    1
    I tried replying numerous times yesterday, but for some reason the forum wouldn't post anything I submitted. So, at risk of being repetitive, I'll try to rehash what I wrote and asked previously.

    I'm using a wired PowerTap with a Cervo 2.4--for a $175, I couldn't say no, though I realize this isn't exactly cutting edge technology here. I'll take what I can get.

    I did the intervals on the flats, maybe a 1% grade at most, in a 50/17 hitting about 140rpm. Started at around 7mph, 30-something rpm. Got up to speed pretty quickly, within five seconds. I've never seen my power go much over 1000 watts, so I may just not have a lot of peak-power capability. Further proof that being able to deadlift 400#, squat nearly 300, and power clean 215# does not contribute to power or speed on the bike!

    I'd love to hear any thoughts on developing better snap. If that's even possible. As I understand it, your phosphagen stores are pretty static, but you may be able to improve the neuromuscular aspect?

    And thanks for the thoughts and replies, I really appreciate the insight.
     
  14. RapDaddyo

    RapDaddyo Active Member

    Joined:
    May 17, 2005
    Messages:
    5,088
    Likes Received:
    41
    I'm still not clear on whether you did a 5sec max power test. It sounds as though you were doing longer duration tests and you're looking at shorter durations as a subset of the longer durations. For one thing, there's no way you want to start a 5s test at 30-something rpm, more likely near 100rpm. A 5s test is an all-out effort from the start and if you go absolutely all out there's no way you can sustain the power for much longer than 5sec.

    As to how much you can increase your NM power, it varies quite a bit from athlete to athlete. I can give you one data point. My untrained 5s power is ~800W and my trained 5s power is ~1200W. So, a 50% increase from trained to untrained, although I don't know if that is an average result.
     
  15. bradg

    bradg New Member

    Joined:
    Apr 3, 2013
    Messages:
    37
    Likes Received:
    1
    I did not do a 5-sec max power test--and I totally failed to clarify that. Although, at the gearing I was on, I'm not sure I would have been able to go stronger or faster? Hard to say. My mindset was "30 seconds" so who's to say.

    So, I rather like your n=1 example of improving 5s power. Would you mind sharing what you did to prompt such an improvement? Because 50% is pretty awesome. I imagine this also took quite awhile to manifest. I've started doing strictly single-leg lifts in the gym, for what it's worth. I do the rear foot elevated split squat (often called Bulgarian, though it didn't originate there), and let me tell you it is humbling. I struggle to move 100# for 5 reps. Which indicates to me that a back squat, front squat, box squat, high-bar squat--whatever, I've read the debates on each of them--recruit a LOT more than just the legs. My guess is that any gym work might be of limited value anyway though, for track sprinters and "general" cyclists alike.
     
  16. daveryanwyoming

    daveryanwyoming Well-Known Member

    Joined:
    Oct 3, 2006
    Messages:
    3,857
    Likes Received:
    97
    I've never seen anyone hit anywhere near their best peak power starting a short sprint like that. Jump off a fast leadout winding your gears at 90 rpm or more before you jump or jump after rolling down a hill to get up to race speeds before you jump. You should hit your peak power for a 5 second maximal effort within one or two seconds at the most, zoom in on the data in your file and if your power curve doesn't jump right up to the peak in the first couple of pedal strokes and ramps up more slowly to the peak then you're overgeared for the jump and working on longer sprint form.

    What you described is fine for longer drawn out sprints but very unlikely to lead to your best short sprint or peak 5 second power numbers. You're turning a peak power exercise into a peak force and torque exercise and most riders will achieve much lower short duration power in that situation.

    Try some all out short jumps from higher starting speeds and at higher pre-jump cadences and work on pouncing on those first few pedal strokes with everything and not ramping up to speed. That and as RDO suggests make sure these are short sprint efforts, don't look at your peak 5 second power from a much longer sprint effort any more than you'd look at your best 5 minute power chopped from a 30 minute or longer maximal interval as an estimate of VO2 Max capabilities.

    -Dave
     
  17. bradg

    bradg New Member

    Joined:
    Apr 3, 2013
    Messages:
    37
    Likes Received:
    1
    Fantastic advice, Dave, and thanks for sharing it. Is it worth it to keep lifting weights? I race track and crits in spring & summer, and then do 'cross in the fall. I'm not a long-distance road racer or mountain biker.
     
  18. RapDaddyo

    RapDaddyo Active Member

    Joined:
    May 17, 2005
    Messages:
    5,088
    Likes Received:
    41
    I sort of figured from your earlier posts that you had not done an actual 5s max power test. It is a totally different animal from a 30s test. As to how I achieved a 50% increase in NMP, there's no magic to it. I did a couple of 5s MP efforts at the end of most road rides with 5min recovery before and after each effort. And once a week I did a focused NMP workout which consisted of 10 x 5s MP efforts with 5mins recovery between efforts. So, a total of about 20 x 5s efforts per week for several months. I have done these on the road and on my trainer with virtually identical numbers. FWIW, I do no lifting. I don't advocate lifting to increase cycling performance, even NMP. I'm sure you can find at least a dozen threads on this forum on that topic, so I won't rehash the arguments here.
     
    bradg likes this.
  19. daveryanwyoming

    daveryanwyoming Well-Known Member

    Joined:
    Oct 3, 2006
    Messages:
    3,857
    Likes Received:
    97
    Just to illustrate the gearing and start cadence tradeoff.

    Given your long sprint power it's likely that you could hit 1200 watts or more for very short sprints (possibly a lot more).

    1200 watts at 90 rpm requires ~75 kg average pedal force or ~150 kg peak pedal force (330 pounds peak force) during each pedal stroke based on normal pedal force distribution curves.

    1200 watts at 30 rpm requires ~ 226 kg average pedal force or ~ 450 kg peak pedal force (990 pounds peak force!).

    You'd have to be one very strong person and able to pull very hard on the bars while hammering down on the pedals with your legs to hit 1200 watts at 30 rpm. The required forces are huge and many times body weight. Even at 90 rpm it's a big force effort to jump hard on the pedals but it's in the realm of possible for many riders.

    IOW, from what you've posted your quickest path to seeing big improvements in peak power and short situation burst sprints is to work on technique and gearing.

    -Dave
     
    bradg likes this.
  20. danfoz

    danfoz Well-Known Member

    Joined:
    Apr 12, 2011
    Messages:
    2,432
    Likes Received:
    92
    My own observations were that lifting didn't help my cycling performance one iota. I have always been more of a sprinty type both during my running track days and on the bike. I have also spent many years lifting. The lifting did not help my 100 and 200 meter times at all. And while I never lifted during any of the seasons I raced bikes, I lifted for a couple years between racing seasons on the bike which didn't seem to add any benefit. My opinion is that sprinting technique (which can most certainly be trained) goes a lot further in maximizing short duration top-end. I.e we are either born pure spinters or we are not. I could very well be misguided and someone with actual data may refute my opinion.
     
    bradg likes this.
Loading...
Loading...