How fast do you lose fitness during detraining (no training)?

sparknote_s said:

I have only been training for about 5 weeks now... For the past 4 days, however, I've been waiting to get a replacement wheel since my back wheel got bent up in a race.I have not been able to bike, since I don't have a spare wheel.

However, I set up an old comfort bike on the trainer and rode for an hour. The first thing I noticed was that it was very hard to get my heart rate past 115. Usually my avg heart rate on training rides is 150. My legs were dog-tired, but my heart rate was only 115! So I kicked it up a bit and finally in the last 30 minutes I heart rate got up to the mid 140s. But this was about as high as it was going to go without REALLY REALLY cranking. I was in the mid 140s HR and I was begging myself to stop, it felt like I was in a time trial or something, it was very hard effort. But my HR was only 140.

Is this because I could have lost so much fitness in just 4 days off the bike, or because it is different riding on a trainer?

Thanks.

COULD be a lot of things, including:

You've been training hard for 5 weeks, and haven't taken enough recovery time for your body to adapt (realize the profit from your training. What you could be seeing is the effect of your training. Are you saying you were putting out the same or greater power, at a lower heart rate? If so.. that is the goal of training! (at least one of them)

If your weren't putting out the same/greater power, then something else could be involved.

Just keep in mind that HR is not necessarily an indication of fitness, in fact after you've ridden for a while, you'll probably learn to rely more and more on your perceived exertion (how hard it feels) and look at other things as references.

In general, takes longer than a week to lose fitness, so I doubt that's the case.

John

I've logged 1400 miles so far this year. More than 2 weeks ago I did a month of "intense training" working as a bike messenger doing 32 to 43 miles per day 5 days a week. Doing this (180 to 166 miles per week) made me a fast biker - at 87% Max Heart rate I would cruise at about 23 mph. Last year I was an 18 mph biker at 87% MHR. This year I started from a winter of no training or not using a trainer for 9 weeks.

See both jpegs below to analyze my improvement in speed for this season and my detraining (loss of speed) from the past two weeks. Unfortunatly I went the last 1.5 weeks with just two bike rides totaling 68 miles - pathetic. 4 days of no biking and then a 23.7 mi ride and then after 5 days of no biking a 44.3 mi ride. This will certainly detrain you as seen from my Excel Jpeg.

In short what my detraining has done to me was make me go from 16.7 mph avg @ 78.92% MHR to 16.5 mph avg @ 82.7% MHR.

So if you're really serious about this sport you should have at least 2 road bikes in case one is down from a crash.

perceived exertion always seem higher on a turbo trainer so it can seem more of a struggle to get your HR up there. overheating is partly to blame.

in my experience you wont lose any 'fitness' in 4 days off the bike but the leags can get a bit dead to the point that intensity does not come so easy. riding again later the same days, or the day after, is likely to give sensations much closer to what your used to.

i think this is why too much total rest before a race is actualy not a good thing.

Mansmind said:

COULD be a lot of things, including:

You've been training hard for 5 weeks, and haven't taken enough recovery time for your body to adapt (realize the profit from your training. What you could be seeing is the effect of your training. Are you saying you were putting out the same or greater power, at a lower heart rate? If so.. that is the goal of training! (at least one of them)

If your weren't putting out the same/greater power, then something else could be involved.

Just keep in mind that HR is not necessarily an indication of fitness, in fact after you've ridden for a while, you'll probably learn to rely more and more on your perceived exertion (how hard it feels) and look at other things as references.

In general, takes longer than a week to lose fitness, so I doubt that's the case.

John

John, your reply says it all....agree 100% with your comments.

Sometimes I think I lose fitness overnight. 🙁

JTE83 said:

I've logged 1400 miles so far this year. More than 2 weeks ago I did a month of "intense training" working as a bike messenger doing 32 to 43 miles per day 5 days a week. Doing this (180 to 166 miles per week) made me a fast biker - at 87% Max Heart rate I would cruise at about 23 mph. Last year I was an 18 mph biker at 87% MHR. This year I started from a winter of no training or not using a trainer for 9 weeks.

See both jpegs below to analyze my improvement in speed for this season and my detraining (loss of speed) from the past two weeks. Unfortunatly I went the last 1.5 weeks with just two bike rides totaling 68 miles - pathetic. 4 days of no biking and then a 23.7 mi ride and then after 5 days of no biking a 44.3 mi ride. This will certainly detrain you as seen from my Excel Jpeg.

In short what my detraining has done to me was make me go from 16.7 mph avg @ 78.92% MHR to 16.5 mph avg @ 82.7% MHR.

So if you're really serious about this sport you should have at least 2 road bikes in case one is down from a crash.

9 days off could be significant, but keep in mind the variability of HR. Your heart rate tends to depress with constant training. Everything from temperature, when you last ate, to how much sleep you got can also affect your HR.

Example: Ride one day `40 miles at 200 watts with avg. HR of 155. Riding the very same route, at the same power the next day you could see your HR drop 4-8 bpm. I've done this.

Conversely, taking time off the bike sort of "gets things back to normal" as it where.

I wouldn't be all that concerned about a .2 mph drop on one ride, that could be due to a lot of factors, including wind, terrain, etc.

Monitoring your heart rate is a good tool, I do it on every ride, but it's just not that precise. I can tell more from perceived exertion, speed over a hill I'm used to, power output, etc.

As one of the other posters mentioned, you may feel your legs "be dead" after getting on the bike again, but that's generally short lived unless you've been off of it for a significant amount of time.

John

dhk said:

John, your reply says it all....agree 100% with your comments.

Thanks dhk, how did your recent century go? Didn't you do the 3 state/3 mountain thing?

I did the MS150 last weekend in Dallas, TX. I learned what Texas hills are (called headwinds anywhere else). There was a point I was generating 300 watts to ride up a SLIGHT rise into the wind to get 12.4 mph. Wind stayed that way all day. I think we average about 15.5 mph over the day. The next day had rolling hills( in OK ) so I felt a little more at home. I think we averaged about 16.5 for the whole 2 day ride. I had a good time other than sucking my rear derailler into the wheel on the first day.

Mansmind said:

Thanks dhk, how did your recent century go? Didn't you do the 3 state/3 mountain thing?

I did the MS150 last weekend in Dallas, TX. I learned what Texas hills are (called headwinds anywhere else). There was a point I was generating 300 watts to ride up a SLIGHT rise into the wind to get 12.4 mph. Wind stayed that way all day. I think we average about 15.5 mph over the day. The next day had rolling hills( in OK ) so I felt a little more at home. I think we averaged about 16.5 for the whole 2 day ride. I had a good time other than sucking my rear derailler into the wheel on the first day.

Skipped the 3 State this year to go on the club's campout and ride in the NC mountains. We did a 62 mile ride with around 9400 ft of elevation gain, so I didn't miss out on all the fun that weekend.

Did an "easier" century in May in TN, and it went fine.....no pain or suffering at all. My goal this year is to be comfortable on centuries; learn to enjoy the ride. The speed is picking up a little too, but that's not my primary concern.

cydewaze said:

Sometimes I think I lose fitness overnight. 🙁

I thought I was the only one that felt like that. It's refreshing to know that I'm not!