Never Miss a Workout

A German reader asked me today how fast fitness is lost if you miss a day or, heaven forbid, several days of training. There are lots of confounding factors here but I’ll take a shot at it.

This is a particularly tender area for me right now as I am missing beaucoup workouts. While in Spain at a training camp two weeks ago I ran into a suddenly opened car door on a ride. It wasn’t a parked car, which I’m always pretty aware of, but rather a car stopped at a traffic light. A passenger decided to get out at mid-block and threw open the door just as I got there. Her timing was perfect. I landed on my hip which was fractured in four places. I’m now 17 days into no training.

So, never miss a workout… Obviously, that’s something which is nearly impossible to attain even if you haven’t broken your pelvis. Life sometimes just gets in the way. So let's take a look at missed workouts--or decreased training--from several varying perspectives.

Here’s what research on detraining by Randy Wilber at the Olympic Training Center in Colorado Springs, Colorado tells us about the changes that happen after three weeks of no training [Wilber]:

Effected Physiology	Change
Heart stroke volume	-10%
Heart rate at submax effort	+4%
Plasma volume	-12%
Capillary density	-7%
Aerobic enzymes	-29%
Blood lactate	+88%
Lactate threshold	-7%
Time to fatigue	-10%
VO2max	-8%

Anaerobic fitness, however, seems to hang on somewhat longer [Coyle]. So it’s aerobic function that we need to be most concerned about, especially since you are undoubtedly an endurance athlete given that you’re reading this blog. Even just reducing the number of aerobic workouts from 5 days per week to 2 causes a loss of significant amounts of fitness [Brynteson]. And reducing the intensity of your aerobic training below 70% of VO2max has been shown to also cause a loss of aerobic fitness with a decrease in aerobic capacity, time to exhaustion and heart size [Hickson].

There is also something relatively new, at least to endurance sport, referred to as “residual fitness” by Vladimir Issurin. This suggests that specific areas of fitness may be lost in a matter of a few days to a few weeks even if adequate training continues in some areas but with little or no specific stress in others [Issurin]. I’ll write more about this topic soon.

Using the WKO+ software model I can also tell you that if your fitness is relatively high you lose fitness at a much faster rate than if it is low. A single missed workout for someone with a CTL (Chronic Training Load) of about 100 TSS/day (high fitness) results in a fitness loss of more than 2%. But an athlete with a CTL of about 20 (low fitness) will see an approximate 0.4% drop in CTL when a day of training is missed. In other words, zeroes are more expensive when you’re highly fit.

So I guess my only hope is to lose a lot of fitness so my rate of fitness loss won’t be too great. That should be easy to pull off. But in the mean time I’m going to do what I can to exercise while I wait out this 6-week down time. I figure that even doing something is better than nothing—but probably more for my head than my body.

References

Coyle, E.F., W.H. Martin, D.R. Sinacore, et al. 1984. Time Course of Loss of Adaptations After Stopping Prolonged Intense Endurance Training. J Appl Physiol. 57:1857-1864.

Wilber, R.L. and R.J. Moffatt. 1994. Physiological and Biochemical Consequence of Detraining in Aerobically Trained Individuals. J Strength Cond Res. 8:110.

Brynteson P, W.E. Sinning. 1973. The Effects of Training Frequencies on the Retention of Cardiovascular Fitness. Med Sci Sports 5(1):29-33.

Hickson, R.C., C. Foster, M.L. Pollock, et al. 1985. Reduced Training Intensities and Loss of Aerobic Power, Endurance and Cardiac Growth. J Appl Physiol 58: 492-499.

Issurin, VB. 2009. Generalized training effects induced by athletic preparation. A review. J Sports Med Phys Fitness. 49(4):333-45.

Comments

[Allison]

Can you comment at all on what you will be doing to maintain aerobic fitness with the hip fractures? I'm a Pro mountain biker that has spent more of the year off the bike than on with foot issues (no fracture, but very painful/swollen/inflamed tissue due to sesamoiditis). I tried swimming but I think due to some foot muscle atrophy wound up stressing my plantar fasciia's.

At any rate, just curious from someone else what options might be aside from anything with the legs! Thanks.

[Linda]

So sorry about the accident and the painful recovery. I'm wondering, though, whether returning to a high level of fitness is quicker for someone who had been highly fit before the layoff. Quick to decline but also quick to rebound?

[Gerd]

Dear Joe,

what I always think about are the long term effects. How does a two week illness effects my form/fitness in 4 months? Or how do 2 months of very reduced workouts effect my fitness one year later?

Any information or experience about this?

Thanks
Greg

[Joe Friel]

Gerd--Depends on what the cause of the missed time was. A virus has been shown to affect blood chemistry for 30 days after symptoms have gone. A year after 2mths of decreased training I seriously doubt if there would be a measurable effect.

[Joe Friel]

Linda--Using the WKO+ model, a highly fit person takes about 5 hours of training to make up for one zero (1 missed workout). For a low-fit athlete it takes about 20 minutes.

[Joe Friel]

Alison--I'll be riding bike on trainer at whatever intensity my injuries will allow. The last few days that has been 1 zone. Not enough to impact aerobic performance. If that doesn't start increasing intensity-wise then I'll swim with a pull buoy.

[Lynda Wallenfels]

Ouch. Sorry to hear about your accident. Heal fast and strong.

[greg Hinrichsen]

Joe, Hope your recovery is quick. Who gets out of a car at a stoplight... Random. I will watch for that one.

What is your position on an athlete taking one day per week completely off. Is the benefit of recovery worth the risk of losing fitness? Do the pros take a day off? Thank you. Greg

[Joe Friel]

Lynda--Thanks. I recall your clavicle break and immediate return to heavy training back in about '98.

[Joe Friel]

Greg--Most of the people I coach take a day off weekly. That is _sometimes_ necessary for athletes.

[Hilton]

Hope you feeling better day to day with the hip Joe. Would that mean though that as the season wears on and you start to concentrate on higher intensity you also loose some of the aerobic fitness in a sacrifice for the anaerobic fitness?

[Rob]

Sorry to hear about your injury Joe. You should consider rehabbing and training on an Alter-G anti-gravity treadmill. There are a few available in your area. You know the benefits of continuing sport-specific training, biking and swimming can't replace running. Your doctor will gradually reduce your weight-bearing restrictions and the treadmill will allow you train at that reduced body weight while maintaining your fitness. Bone healing will probably be better also considering that running improves bone density whereas biking might actually diminish it.

[Joe Friel]

Hilton--It depends on how you periodize your training. If you neglect aerobic endurance then there is likely to be some erosion of this ability over several weeks.

[Jay Talbott]

Joe,

Good luck in the recovery. Be a patient--patient, but stay as active as you can.

Jay

[Herm]

What a freakish accident, that's tough Joe.

I train 4 days a week, but run 10 miles each day (about 90-95 minutes), then 2 to 2 1/2 hours on the weekend for my long run. I find the 4 day schedule very easy to manage around life. I've read that one long run is more beneficial than two shorter ones, but am I negating that benefit by missing 3 days a week? Between 6x 7 mile and 4x 10 mile schedules, does one have significant advantages over the other?

[TJ]

Hi Joe -- tough luck! I had a pelvic stress fracture (in the midst of a half) and know it isn't a pleasant injury. For me, the mental adjustment was way more painful then the physical injury. But, I'm back and cycling and running longer and faster than ever (I'm a master), thanks in no small part to your book and blog postings.

Good luck!

[Joe Friel]

Herm--I try to have my triathletes not go more than 2 days without doing a workout in a given sport, esp in the last 12 weeks (Build period).

[gwendolyn oguin]

Joe: Good Lord, who would ever think of someone getting out of their car at a stop sign. I am sending you tons of healing energy and I know you will recover well. You are a smart guy. At least you can watch some of the spring classics. Take care of yourself. Gwendolyn O'Guin Portland Maine

[David Tichy]

Hi Joe...sorry to hear of your accident, and take it easy and heal well. May be you could get one of those motors to put in the down tube of your bike (you know the one they said Cancellara had)to turn the legs over until they heal.:-) Rest well..

Cheers David

[CD]

Hi Joe,
So sorry to hear of your injury.
Please consider using a grounding pad to speed your healing. Dr. Spencer, who works with elite athletes, used it in with his clients during 4 Tour de France competitions. His description of its amazing effectiveness is described in the book "Earthing" by Clint Ober et al. You can purchase the pads at Grounded.com
Heal strong,
~C

[Mike Weber]

Hi Joe,
I rarely go a day without reading part of the "Bible". I have been sick with the flu for 5 days buy starting to feel better. How quickly should I return to training and at what intensity? I just missed week 4 of Build 1. Thanks for the great books and articles!
-Mike

[Joe Friel]

Mike W--I'd suggest spending 10 days to 2 weeks focused on aerobic endurance training. Good luck.

[how to build muscle]

Its so true that you should never miss a workout because it promotes cardiovascular training, strength training and stretches. Without it, your healthy life style is not complete. Thanks!

[PedalFaster]

Sorry about the accident.

Those are great studies about the effects of detraining. Are there similar studies of how quickly those adaptations return when training resumes? Do they return faster than they took to build the first time (I would hope).

As always, thanks for the insight of your blog.

[Joe Friel]

pedalfast--Don't know. I'd have to go back and check the research, if there is indeed such research (which I doubt).