It appears every year I put some time on the bike and begin riding and feeling great. Say December thru July. Then I go on vacation for two weeks and I never feel that great after I come back, putting the same distance in just not feeling as strong. Do you really lose that much fitness just taking two weeks off? What is a quick fix to get back on track is it just putting more time in the saddle?

I'd be interested in hearing what you guys have to say about this too as Im just about to go on vacation and usually feel the same (dead legs) once I return.

This is my first year Im training with powermeters so I have numbers to back it up. One week off the bike last easter was enough for me to lose about 15-20W off my FTP. It then took about 4 weeks of regular training to bring my values back up to where they were.

I guess the best way is to fully ramp up your training the 2 last weeks before you leave increasing your ATL sky high.

At the moment I have a CTL of 120 (form). After my week off I will probably have a CTL of 80-90. Once I get back If I were to put in very long or intense rides (ATL) in a short period of time it could be possible get my CTL back to where it was in 1 week. Under normal circumstances it takes way longer (about 30days).

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Canyon Ultimate SLX 2013 + DA9070 + Red Quarq + Corima Aero+ MCC (Ordered! 6.0kg)
Canyon AeroRoad + DA9000 + Lightning Power2Max + MCU's (6.5kg)
Cervelo P4 + G3 Powertap (7.78kg)
Cervelo SLC + SRAM Red 2013 + Red Quarq (6.8kg)

G6612 to answer your question. 2 weeks off will roughly bring your form (CTL) to half. To bring it up to exactly where it was you would need to do one of the following:

1) If you train just like you trained before (same length/same intensity) it will take you 45days to bring your form (CTL) to where it was.
2) Really intense first week (will be very hard to execute) and then back to your normal routine will bring your form back faster and can be maybe done in 1 week or 2.
3) Last option is probably the best way to go by. Ease your way in the first week and then really ramp up the intensity until you get your CTL back.

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Canyon Ultimate SLX 2013 + DA9070 + Red Quarq + Corima Aero+ MCC (Ordered! 6.0kg)
Canyon AeroRoad + DA9000 + Lightning Power2Max + MCU's (6.5kg)
Cervelo P4 + G3 Powertap (7.78kg)
Cervelo SLC + SRAM Red 2013 + Red Quarq (6.8kg)

Taking 2 weeks off from the bike should not affect your previous fitness too bad.
Getting back to your previous fitness level will depend on your previous training level and your age.

It would be best if you eased back into form and you will notice you will reach your previous form a lot quicker than
you did when you were trying to reach form back in the early part of the season.
It again depends on your previous fitness level and age.

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I never took drugs to improve my performance at any time. I will be willing to stick my finger into a polygraph test if anyone with big media pull wants to take issue. If you buy a signed poster now it will not be tarnished later. --Graeme Obree

Surely the right thing to do is to do some maintenance exercises say 2x per week to keep some of the gains?