Can you lose fitness during a taper?

I have read, and personally observed, that HR during a race does not correlate to HR in training; you tend towards a higher HR for the same pace, due to adrenaline and the thrill of racing.  That doesn't mean HR is worthless, it just means we need to figure out what the numbers tell us and why.

Another thing to consider is that three weeks might be too long, and that you might have cut too much mileage.  While I don't think you lost fitness per se, I think you might have degraded your ability to perform at peak.  Peaking for a race is tricky business, and elites don't always get it right, so chances are we aren't either.

Tapering is nothing more than reducing training load enough to allow your body to recover while doing enough to sustain the maximum amount of gained fitness. Every time you train you get fitter but you also can get proportionally more fatigue. Think it like this, every time you train you earn fitness and fatigue points. Usually fatigue points worth more than fitness point but fitness points linger longer than fatigue ones. IOW you get more tired after a session but you recover faster and the adaptation gains (fitness) will last longer.

When you taper is because your main goal is to perform at your very best on race day. You are allowing your body to recover while maintaining your hard earned fitness. When athlete race with partial or no tapering it just means that while they still will strive for the best possible performance on race day given their current fitness level + chronic fatigue, the result won't be as good as if they were rested.

Since athletes can only achieve a few top peak performances (max) every season, that’s why they allocate priorities to races labeling A, B, C races. The A races are those in which the athlete will taper 100% in hopes to achieve peak performance, B races are those in which the athlete will taper partially to achieve a solid performance and C races are those in which the athlete won’t taper, still a good performance might be desired but not granted.

In the end, tapering for you will vary based on your fitness, experience, genes, etc. If you are following a plan just follow it and while training pay attention how fast or not you recover from hard/long sessions. Somewhere along training you’ll learn how much tapering you’ll need. Good luck!

Tapering is nothing more than reducing training load enough to allow your body to recover while doing enough to sustain the maximum amount of gained fitness. Every time you train you get fitter but you also can get proportionally more fatigued. Think it like this, every time you train you earn fitness and fatigue points. Usually fatigue points worth more than fitness point but fitness points linger longer than fatigue ones. IOW you get more tired after a session but you recover faster and the adaptation gains (fitness) will last longer.

To visually describe Jorge's post.. in my log I my fitness to see where I am.. I am recovering from surgery so I do not want to kill myself with workouts, but want to have a steady build.



In the graph  the blue line is fitness (Chronic training load - CTL), the blue bars are workouts (They receive a training stress score), and the pink line is fatigue (Acute training load - ATL).. the yellow line is my training stress balance (TSB)... the difference between fatigue and current fitness.  A negative yellow line (TSB) means I have a high training load for my fitness.. a positive TSB means I have tapered and am ready to rock it.  

Right now I can only bike so you can see the impact when I go a few days without a bike.. the very large workout took more of a toll than expected on my back, so I took a few days off. 

So basically there is a quick visual on fatigue/taper.