W/KG or Absolute for 5 Sec Power



objective

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Jul 5, 2005
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Which should a sprinter (crits, flat road races, endurance track) pay most attention to [1] absolute watts OR [2] watts per kilo?

I'm thinking that [1] watts per kilo is less important than absolute wattage because, it seems to me that, how much air a person pushes is the real trouble when on the flats. I happen to be on the smaller side at 5' 8'' and 155 lbs. ([size=+1]172.7 cm / 70.3 kg[/size]) and don't think my CdA changes that much in the winter when I am ~15 lbs heavier. However, I do put out more absolute watts when I am fat. My theory is that my best 5 second power comes from sprints done out of the saddle and that being heavy has an advantage over this time period.

Am I thinking clearly? Should continue on my quest to get McEwen lean or should I eat some cake?

BTW, I'd like my assertion to be wrong as my absolute numbers are not great...
 
objective said:
Which should a sprinter (crits, flat road races, endurance track) pay most attention to [1] absolute watts OR [2] watts per kilo?

I'm thinking that [1] watts per kilo is less important than absolute wattage because, it seems to me that, how much air a person pushes is the real trouble when on the flats. I happen to be on the smaller side at 5' 8'' and 155 lbs. ([size=+1]172.7 cm / 70.3 kg[/size]) and don't think my CdA changes that much in the winter when I am ~15 lbs heavier. However, I do put out more absolute watts when I am fat. My theory is that my best 5 second power comes from sprints done out of the saddle and that being heavy has an advantage over this time period.

Am I thinking clearly? Should continue on my quest to get McEwen lean or should I eat some cake?

BTW, I'd like my assertion to be wrong as my absolute numbers are not great...
Both are helpful but W/kg is probably the most useful metric since 5 sec and neuromuscular power is normally associated with accelerating the bike/rider - hence a better w/kg will mean you can accelerate more rapidly, which is typically what we want (I don't mind winning sprints if I can do so with less absolute power). Once up to max speed, then outright power does provide a solid indication of ability to push through the air but by then your 5sec power is long gone....
 
Alex Simmons said:
Both are helpful but W/kg is probably the most useful metric since 5 sec and neuromuscular power is normally associated with accelerating the bike/rider - hence a better w/kg will mean you can accelerate more rapidly, which is typically what we want (I don't mind winning sprints if I can do so with less absolute power). Once up to max speed, then outright power does provide a solid indication of ability to push through the air but by then your 5sec power is long gone....
Good point. I had not considered the effect of body weight on the all important jump.
 
5s power might be a good guide for neuromuscular power but i find that 10 - 15s power is a better guage of spinting ability... a sprint has two phases... acceleration followed by a short "speed endurance" phase when you try to ride as long as possible while having your power drop off as little as possible. 5s power doesn't take into account this second important phase, so IMO it is not a good guage of sprinting ability which is not equal entirely to neuromuscular power.

not sure where i exactly stand on W/kg... kg does vary with the amount of air you punch out too but it would seem that it doesn't coun't as much as a straight W/kg would suggest... seems to me that as the other poster said if acceleration is important in a given situation, and it isn't always the case, then W/kg will be significant, but if the sprint starts at 60km/hr and if really about who can just bump it up to 63km/h or can just hang on with the highest power ,then W/kg is less significant. i guess if you looked at both you could determine what your abilities are and what your stategy should be in a sprint.
 
doctorSpoc said:
guess if you looked at both you could determine what your abilities are and what your stategy should be in a sprint.
Good points.

I'm mostly interested in how to go about training these durations and what metrics to use for assessing progress.
 
i do a neuro muscular power/sprint workout once a week...

should do it fully rested (i.e. after a rest day) 1-1.5hr workout...

- 15-20min warmup (can just ride out Endurance to Tempo pace to where you can safely do the workout)
- nice to have a place where there is a short (100-200mm) downhill (~1-2%) followed by a very gradual false flat up
- i do 2x standing starts (or nearly so... just slow down as much as possible) up the hill.. 5-10s... don't grind out to the end just get "on top of the gear" and shut it down.. these are really just to get warmed up
- 3-4x rolling starts down the hill.. roll down the hill to get up to speed (35-40km/hr) should not take much effort.. as you reach the bottom of the hill do 100% effort... ~10s but not more than 15s.. standing for the acceleration then seated after about 5s trying to maintian your power and speed... really think about how your pedaling and feel your way around to the best pedaling technique
- 4-5min full recovery between efforts
- then ride home

the workout should feel easy but it will be very effective if you do it on a regular basis at least once a week... you could even do it in the morning and do something else in the afternoon/evening if you have that kind of time...

the 5s acceleration... after you get techinque down is almost entirely genetic but the second "speed endurance" phase needs to be trained... standing start followed rolling starts take care of both areas...
 
doctorSpoc said:
i do a neuro muscular power/sprint workout once a week...

should do it fully rested (i.e. after a rest day) 1-1.5hr workout...

- 15-20min warmup (can just ride out Endurance to Tempo pace to where you can safely do the workout)
- nice to have a place where there is a short (100-200mm) downhill (~1-2%) followed by a very gradual false flat up
- i do 2x standing starts (or nearly so... just slow down as much as possible) up the hill.. 5-10s... don't grind out to the end just get "on top of the gear" and shut it down.. these are really just to get warmed up
- 3-4x rolling starts down the hill.. roll down the hill to get up to speed (35-40km/hr) should not take much effort.. as you reach the bottom of the hill do 100% effort... ~10s but not more than 15s.. standing for the acceleration then seated after about 5s trying to maintian your power and speed... really think about how your pedaling and feel your way around to the best pedaling technique
- 4-5min full recovery between efforts
- then ride home

the workout should feel easy but it will be very effective if you do it on a regular basis at least once a week... you could even do it in the morning and do something else in the afternoon/evening if you have that kind of time...

the 5s acceleration... after you get techinque down is almost entirely genetic but the second "speed endurance" phase needs to be trained... standing start followed rolling starts take care of both areas...
Thanks for the pointers.

What's your typical TSS for a session like this? What are your thought regarding doing this workout and then doing some SST? I'm thinking of including sprint workouts 3X a week starting next month but I can't "afford" to do only that. In other words, I want to be sure to keep my CTL while I start adding sprint specific work.

Can a sprint specific session give me 100-130 TSS in 90 minutes?
 
objective said:
Can a sprint specific session give me 100-130 TSS in 90 minutes?
If you don't overdo the recoveries, sure. Personally, I do 30-45 min of sprints and then go ride some tempo, as you first mentioned.
 
frenchyge said:
Here's an extensive <finger quotes> discussion </finger quotes> on that topic.

http://www.cyclingforums.com/t-349905-15-2.html

Start reading at about post #17.
Ah, yes. I remember that doonybrook. ;-) Here's a statement from Andy that clears things up for me.


...with CdA correlating reasonably closely with height, and hence secondarily with mass. Thus, W/kg is a better predictor of speed against wind resistance than W alone, even though mass, per se, doesn't directly influence wind resistance.
 
objective said:
Thanks for the pointers.

What's your typical TSS for a session like this? What are your thought regarding doing this workout and then doing some SST? I'm thinking of including sprint workouts 3X a week starting next month but I can't "afford" to do only that. In other words, I want to be sure to keep my CTL while I start adding sprint specific work.

Can a sprint specific session give me 100-130 TSS in 90 minutes?
looking back at my workouts i see TSS of mid 70s for 1 hr so add in a slightly longer route home @ SST+ and you would probably end up at about 100 or so over 90min... but if i was going to include structured sprint workout 3x a week i'd likely only do 2 or 3 sprints in a workout and then go do my SST or whatever... i tend to like to do one structured sprint workout and then do unstructured sprints in my other workouts.. i don't think you need that much structured sprints and i personally wouldn't give up that much time in my other workouts to accomdate the sprints... but sprint here and there.. town sign etc is fine and breaks up longish workouts... and acts as a kind of real world testing.. but you need the dedicated, structured training in order to aquire proper technique... and really think about what you're doing so you can improve