I can't break the 5 mile barrier!

[XmisterIS]

This is annoying me!

There's a 7 mile commute that I do sometimes (14 mile round trip).

It is totally flat and so is perfect for sprint training.

My goal is to be able to sprint, flat out, for the whole 7 miles home (and then collapse! Lol!).

So far I can only get the first 5 miles at a sprint pace (5 miles in 12 minutes - I make that 25mph). Then, all of a sudden, I hit a "wall", all the strength goes from my legs and I do the remaining 2 miles in 8 minutes! (I make that 15 mph).

Note that these times are in the absence of wind (last night was totally calm) - I've done the whole journey at an average of 30mph before - but with a howling tailwind!

Once I've hit the "wall", it doesn't matter how hard I try and push the pedals round faster, they just won't go faster! It's like my brain is saying to my legs "push, damn you!", and my legs are saying, "no!".

What can I do to train to sprint the whole 7 miles? (I calculate just under 17 minutes if I can keep 25 mph up all the way). I just can't get through the 5 mile wall!

 

[Twenty Inch]

Glycogen getting used up - eat a couple of bananas about 40 mins before you set out tonight, let us know how you get on.

 

[WimbledonCyclist]

Hm, the physiology doesn't quite work.

No one can do a 12 minute "sprint" - imagine Usain Bolt running flat out for 12 minutes. The guy would break every conceivable running record.

If you're pedalling along calmly, most of your energy is produced by burning fuel using oxygen. You'll be able to sustain this for ages. Pedal much faster, and your body will need to produce so much energy that it taps into another energy system: it starts to burn fuel without oxygen. Byproduct of this process is lactic acid. And there's only so much lactic acid your muscles can take.

All you can do is aim to train both energy systems. Increase your aerobic fitness by endurance training. Anaerobic fitness is a bit more complex. You'll be able to do lactic acid production sets often, almost daily (just put in a few maximum acceleration efforts of about 20 seconds a time). Also boost your ability to tolerate and buffer lactic acid by occasional hard efforts that you sustain for longer periods: say a 15-minute max effort. Don't do that too often - it hurts, and you'll need time to replenish the stores of fuel in your muscles. Also, if you put in max efforts all the time at the expense of "endurance training", you'll lose some basic endurance/aerobic capacity, simply because you do too little endurance training.

 

[HLaB]

Keep going you'll get there. I've found prehydration usesfull before big rides.

 

[I am Spartacus]

errrrr 'flat out' meaning working @ anaerobic level?
can't be done for that length of time
you need to increase your ability to work @ critical power for the longer timescale

Joe Friel for instance has written power based training schedules
Eating a banana aint gonna cut it tho'

( riding in a chain gang/club run is always good (cheap) training)

 

[XmisterIS]

I see what you guys are saying about the "flat out" bit. No, it's not totally "flat out" anaerobic, or else I would turn blue, vomit and collapse!

What I mean is that I ride for 12 minutes at a level where I am breathing as hard as is humanly possible, legs and lungs feel like they're about to explode, sweat pouring off me. Then I hit the wall!

I usually do endurance stuff, so I deliberately put the high speed (ok I won't call it a sprint!) run in to try to push my fitness level up.

I must say that when I get off the bike at the end, my legs go all wobbly and I feel dizzy. It also takes about 5 minutes for the sweat to stop pouring out of me!

 

[trustysteed]

isn't the more obvious solution to ride at a pace slightly slower than the 5 mile pace that allows you to keep going for the 7 miles at a constant speed? than as you get fitter that average pace over the 7 mile distance will start to come up until you'll be able to do the 5 mile pace you originally started with over the full distance?

i can sprint my arse off for 100 yards but i know i can't keep that pace going for a mile. but i know i can ride that mile in a constant speed from start to finish and as i get fitter, my mile time will improve.

 

[XmisterIS]

This is true - and I can ride the whole route in about the same total time, but with more even speed throughout. The trouble is knowing just how much harder to push it each time!

 

[I am Spartacus]

What I mean is that I ride for 12 minutes at a level where I am breathing as hard as is humanly possible, legs and lungs feel like they're about to explode, sweat pouring off me. Then I hit the wall!

This will cost you normally €99..
do 4 of the above with 5 -10 mins recovery in between

 

[trustysteed]

This is true - and I can ride the whole route in about the same total time, but with more even speed throughout. The trouble is knowing just how much harder to push it each time!

do you have a trip computer? you can start to keep track of your average speed and if you have one with a pacer function, it shows you whether you're above or below your current average speed.

for example, say you do the 7 miles in an average of 14 mph one day. next time your ride, you know you need to ride at an average speed of 14.1 mph in order to improve. keeping an eye on your average speed on the computer will enable you to keep pushing at 14.1 and the pacer arrow will let you know whether you're currently above or below it.

 

[I am Spartacus]

Speed is irrelevant.... all about power

 

[jimboalee]

Speed is irrelevant.... all about power

How do you estimate power requirement if you haven't got the luxury of Powertap or SRM cranks?