addicted2wheels

Folks, I've just spent a bit of time looking at crank lengths. I won't pass judgement, but I will say from my experience a longer crank works better for me, especially on the road, unless clearance is a factor. I currently use 172.5mm cranks on my crit and road bikes and 165.o on my track bike. Most 'crank length calculators' tell me that I should use 165mm cranks all of the time, but it doesn't seem to matter that much in practice. Unless of course you are using long cranks on a steep velodrome or in a tight-cornered crit - then you risk bottoming-out a pedal. Or if you swap bikes a lot (I once crashed spectacularly at a road circuit in Warriewood, Sydney, when I was balked by a car mid corner. I forgot I was on my Colnago with 175mm cranks and hit a pedal at bottom dead centre. I was too used to using my 'crit bike' with 170mm cranks at Heffron Park and simply forgot to stop pedalling around the only sharp corner that mattered). It can get dicey.

Anyway, some resources for you:
Cranklength.info
Bicyclesource.com
Sheldon on cranks
Netally goes into detail on research

I enjoyed the read and I think I've decided I'll stay with what I've got, thanks. 172.5 isn't causing me any pain, so I'll stick with it for now. However I may drop from 53 to 50 teeth on my big ring... hmmm.

Does Creatine supplementation work?

Firstly it has been shown in past studies that Creatine supplementation will attenuate increases in plasma ammonia and hypoxanthine during intense endurance exercise lasting 1 hour. So it seems reasonable to suggest that Creatine supplementation may indeed improve muscle energy balance during such exercise - it's worth testing.

The authors report that Creatine supplementation significantly increased muscle total Creatine, however no difference was seen between treatments after the first 45 min of exercise. They conclude that "raising muscle
total Creatine content before exercise appears to improve the ability of the muscle to maintain energy balance during intense aerobic exercise, but not during more moderate exercise intensities".

Title:Creatine Supplementation Reduces Muscle Inosine Monophosphate during Endurance Exercise in Humans.
Authors: McConell, Shinewell, Stephens, Stathis, Canny and Snow
From: Department of Physiology, Monash University; Department of Physiology, University of Melbourne;
Exercise Metabolism Unit, Centre for Rehabilitation, Exercise and Sport Science, Victoria University of Technology; School of Health Sciences, Deakin University.
Source: Medicine & Science in Sports & Exercise; Dec2005, Vol. 37
Issue 12, p2054-2061

My take on this is that Creatine supplementation appears to work in maintaining a balance in the ATP cycle during the intense 1 hour efforts that have been tested. This sounds like an A or B grader may benefit in a 1 hour criterium, for example. They may have more energy freely available at the end of the race and secondly (my guess!) may recharge quicker afterwards. However there's no benefit below one hour or at moderate rather than intense efforts. As always, tread carefully if you try any supplementation - and seek a wide range of advice beforehand.

Sounds like a cool study. The authors examined "patterns of leg muscle recruitment and co-activation, and the relationship between muscle recruitment and cadence, in highly trained cyclists". They tested at "individual preferred cadence, 57.5, 77.5 and 92.5 revs min" using (one
hopes) carefully placed electrodes. Sounds cool as well. And the findings? Well the authors say that "muscle recruitment patterns varied from those previously reported, but there was little variation in muscle recruitment between these highly trained cyclists". Specifically the "tibialis posterior, peroneus longus and soleus were recruited in a single, short burst of activity during the downstroke" and that "the tibialis anterior and gastrocnemius lateralis were recruited in a biphasic and alternating manner". They found that "contrary to existing hypotheses, our results indicate little co-activation between the tibialis posterior and peroneus longus".

So far so good. Muscle recruitment is important from many angles, not simply as an academic pursuit but as an aid to understanding how it is we can generate the power that we do and applying that understanding in coaching athletes in optimal patterns of training. Such understanding would also help avoid injury as well as assist in faster healing after injury.

Anyway, the authors found that "peak EMG amplitude increased linearly with cadence and did not decrease at individual preferred cadence. There was little variation in patterns of muscle recruitment or co-activation with changes in cadence". I take this to mean that most elite cyclists use the same muscles and that varying cadence does not significantly change the pattern of recruitment. In other words you are still using the same muscles, irrespective of the tested cadences.

Reference: Leg muscle recruitment in highly trained cyclists.
Authors: Chapman, Vicenzino, Blanch, Knox and Hodges from the Division of Physiotherapy, The University of Queensland, Brisbane, QLD, Australia and the Department of Physical Therapies, Australian Institute of Sport, Bruce, ACT, Australia.
Source: Journal of Sports Sciences; Feb2006, Vol. 24 Issue 2, p115-124

My view: For me this means that Lance Armstrong spinning at 110 revs/minute is probably using the same muscles as Jan Ullrich at 90 revs/minute. It's important to pin that down. Higher cadences do not necessarily mean a different arrangement of muscles doing the work.
Beyond that important point, there are neuromuscular factors involved as well as the lower per-rev power output at higher revs, so a comparison and conclusion Lance vs Jan isn't going to happen here. However I think it's interesting to note that seating position could affect the outcome. To me Jan looks cramped on the bike. Highly effective but a little less comfy than Lance. Perhaps (this is me postulating, not the authors above!) position will be a defining factor and possibly cadence is less important to the ultimate outcome than we have imagined. Any professional opinions on this out there?

Folks, please tread warily whilst travelling the Internet. It's hard to
separate truth from fiction or opinion from science wherever you are -
but it's worth getting a second opinion, irrespective. When you chance
upon an impressive website "in print" (as it were) it can easily seem
like the last word on a subject. In fact we have no final judgement on
anything, anywhere - only fallible human opinions. And this blog is all
about sharing those opinions.

I will quote published research that seems relevant (to me) on
particular subjects. You can then read my opinion, my take on the matter
presented. I don't always have a relevant degree in the field - my
degrees are in business administration and human resource management -
but I do often have relevant experience and I will share that experience
with you. It's not prescriptive, it's not advice. Hopefully, though,
it's interesting and thought-provoking. Please read widely and examine
claims critically. And don't forget to comment.

Well it's nice to see it proven.

At least in one experiment, anyway. My take on this is that an upright cycling posture is better than a supine one, if only when looking at a lab test of endurance.

I once 'raced' a recumbent with full aero fairings along a freeway from Bargo to Picton in NSW, Australia. I (on my 'real' bike) had more power up the hills but he certainly had the top speed advantage! So there is certainly an aero advantage to 'lying down on the job' but from a physical endurance perspective there's a decided disadvantage of some 10%. Anyway...

From the European Journal of Applied Physiology; Jan2006, Vol. 96 Issue 1, p1-9. Authors: Egaña, Green, Garrigan and Warmington, from the Department of Physiology, Trinity College Dublin, Ireland and the School of Biological, Biomedical and Molecular Sciences, University of New England, NSW, Australia.

To quote from the abstract, "The time sustained during a graded cycle exercise is ~10% longer in an upright compared with a supine posture. However, during constant-load cycling this effect is unknown. Therefore, we tested the postural effect on the performance of
high-intensity constant-load cycling." So they tested constant-load and found that "there is a very large postural effect on performance during constant-load cycling exercise and this effect is significantly larger in men than women". So upright beats supine, particularly for men. Not sure what this means to the crazy racing folk who sit on an 'upright' bike but bend down so far that they are almost parallel to the ground but I suspect they are successfully adapting the efficient upright style to gain an aero advantage. The racing tuck is a compromise,
and of course we can always sit up and stretch.

Other compromises made for racing include the need to 'pull up' on the bars when climbing or sprinting, so the bars have to be close enough to do so comfortably whilst being low enough to gain an aero advantage. Anyway, I suspect it still beats lying down!

Aside from all that, recumbents are almost invisible and need a flag on
a pole to be seen. They are pretty cool devices though.

posted by gtveloce  # 1/24/2006 11:46:00 PM 0 Comments Links to this post