Acro Image

Aerobatics Server

ACRO E-mail Archive Thread: [Acro] Re: Cardio and G tolerance- all the replies

[International Aerobatic Club] [Communications] [Aerobatics Images]

Disclaimer: These aerobatics pages are developed by individual IAC members and do not represent official IAC policy or opinion.

[Usage Statistics]

ACRO E-mail Archive Thread: [Acro] Re: Cardio and G tolerance- all the replies


Thread: [Acro] Re: Cardio and G tolerance- all the replies

Message: [Acro] Re: Cardio and G tolerance- all the replies

Follow-Up To: ACRO Email list (for List Members only)

From: "David Magaw" <dmagaw at>

Date: Tue, 07 May 2002 22:24:15 UTC


Thank you Eric.  
  ----- Original Message ----- 
  From: Eric Minnis 
  To: acro at 
  Sent: Tuesday, May 07, 2002 2:48 PM
  Subject: [Acro] Cardio and G tolerance- all the replies

  I had a ton of request to post some of the replies so here goes. I removed the names from the replies because it was so hard to cut and paste but I am sure you can figure out several of them. There is some excellent information and a good bit of actual experience. Thanks again to all that replied!

  Eric Minnis

  N43740 Swick Tcraft




  For what it's worth, here's my story. When I started to fly acro I was an avid bike rider (about 25-30 miles a day). At the time I was flying a Great Lakes and I found that in the hard pulls (+5) I would start to gray out, even with a full grunt going. What made me realize that acro and distance biking was not compatible for me was my instructor having me fly a hammerhead and pull directly into a loop at the bottom without grunting. Next thing I remember was my instructor's voice somewhere off in dream land telling me that he had control of the aircraft and to sit back and relax. Also keep in mind that "time in G" can be a factor as well. Whereas 7 or 8 Gs can put you out right now, 3 or 4 Gs for 30 seconds can induce G-loc as well. 

  I think military fighter pilots are limited on how much cardio they are allowed to do as well. I think it's something like 30min three times a week.


  I found that once I moved into the competition box I could no longer tolerate the bike riding. Once in the box the maneuvers come much faster than in practice and for me, I found it hard to keep my G tolerance up under those circumstances.


  As my instructor once told me "fat guys can handle more Gs".



  I have been flying competition for about 15 years and currently fly an Extra 300 in advanced.  I have been running for 25 years, marathoned for a number of years in the late 70's and early 80's, and currently run about 40 miles a week, bike about 40 miles a week, and do light weight training 2-3 times a week.  My comments are purely from experience, not technical or medical.  Clearly, dehydration affects G tolerance.  I pay close attention in hot weather to hydration, especially when flying.  Overall, the lower blood pressure associated with good aerobic fitness can reduce G tolerance, but I have not found it to be a big problem.  Work at developing good techniques during flying to maintain blood to the brain---various gruntings and squeezings.  There is plenty written about these techniques.  Be careful on your long run days if you plan of flying.  In the summer here, mornings are better for running and flying, and I notice more "gray" time if I go straight from a run to a flight.  Positive seems to have more effect than negative, but again it is a blood pressure and flow issue, so the transitions between positive and negative will catch you quicker if you are dehydrated, or prior to hydration after a run.  We all choose how to manage our interests, and while running does conflict with flying sometimes, I have never felt the need to drop either.  I am sort of a perenial advanced competitor.  If I really worked hard and wanted to fly unlimited on a regular basis, I might need to temper running.  But so far that has not been my goal with flying so I've not felt compelled to cut back.


  I have always been told that running can affect

  your G Tolerance, but I have been a runner all of my

  life, I have run 15 marathons and I lift weights, 5-6

  days a week and I have not had a problem with G

  tolerance.  I have been flying acro now for close to 8

  years and have competed throughout that time.  The

  net-net is that being  fit, is always better than not

  being fit.  



  Most civilian, nonmilitary, planes cannot sustain high G's long enough for your cardio training to be a factor.  If your acro was in a F-16, F-18 etc. where sustainable G's are available, weight training would be an excellent thing to do.


  Your are not going to have a problem, It is mostly  with the Unlimited folks that problems occur.   If you are having problems during a pull be sure the you tighten the stomach and butt muscles before the pull. Another helpful hint is to turn your head to the side if you really start to get light in the head during a pull, this seems to restrict the neck blood flow.



  I fly a S2A.  Run and work out daily - I fly acro three times a week - 3 slots of 45 min per afternoon. I do flight training on weekends - some doing loops, spins and rolls  - no snaps - in a clip wing.


  Been doing the acro for about three years, the running forever and weights for about four. Currently running doing five miles in 30 minutes pulse rate tops out at 175. Although 20 years ago I was doing it iin 20 minutes!



  Ted Wheeler does acro and a lot of running (does Iron Man competitions, I 

  believe, and is currently or just recently on Everest so might not respond 

  for a while).  He might be able to answer with personal (ie- anecdotal) 

  experience.  He's at ted_wheeler at


  Also if you haven't already heard from Scott Poehlman (who I bought my S2B 

  share from), you may want to contact him.  He's an acro pilot and doctor, 

  and is currently writing the Human Factors column in the magazine.  I don't 

  have his email but can get you his phone number if you'd like.



  Myth.  Myth, myth, myth.


  Cardio is GOOD for G-tolerance, as is weight training.  Cardio because your heart can pump more blood, weight training to help with anti-G straining maneuvers.




  I am the IAC Human Factors Chair, as well as a practicing physician. My first advice to you about G tolerance is to read the article in the most recent Sport Aerobatics--which covers positive g tolerance issues. In Primary and Sportsman, positive G tolerance is really the only issue. It references an Adivsory Circular (I _think_ AC 91-61, but I don't have the references here in front of me)--go get that AC--you can get it off the AOPA web site.


  As far as training is concerned, the "classical wisdom" in aerobatics is that strength training, particularly lower body strength training improves positive G tolerance, while aerobic conditioning, such a running, particularly long distance endurance running impairs G tolerance. This makes very good sense from a theoretical basis, since aerobic endurance training increase vagal tone and lower heart rate, and intrinsically lowers resting blood pressure.  All of these are important compensatory mechansisms in the response that allows tolerance to positive Gz.


  Fortunately (or un-...) none of this theorizing is borne out by actual data. In the studies that have been published looking at exercise and G tolerance to date, no one has seen an increase in positive Gz tolerance as a result of strength training, NOR have they seen a diminution of G tolerance when subjects are aerobically trained. I am presently working with a personal trainer and exercise physiologist here in Austin, and you'll see a more detailed answer to this question sometime in the Fall in Sport Aerobatics.


  For the present, my advice has to be something like this: "I wouldn't radically change my exercise program and expect my G tolerance to remain the same. However, if you have a program that works for you and you are able to maintain reasonable G tolerance, then press on, because it is better to exercise than not."


  Hope this help--if I can give you any further info, please feel free to e-mail me directly.



  I have competed in bodybuilding and in cycling and speedskating at the 

  national level for many years. I compete in Advanced category (Sukhoi SU29 

  and Pitts S1T).  

  In my experience, the weight lifting increases G tolerance.  Aerobic training 

  has not adversely affected my G tolerance ,possibly due to the weight 

  lifting. I am used to +7/-5 in the Suke and +6/-4 in the Pitts.  Dehydration 

  from a long aerobic training session will  lower G tolerance dangerously.  

  Capillarization anaerobic (lactate) workouts can cause some pooling of blood. 

  This would be a workout such as one legged squats  X  50 reps each leg at a 1 

  /sec pace with a new set each minute, done for 30 to 60 minutes straight.  

  This ruins my G tolerance, so I don't even do them until after aerobatic 

  season is over.   Extra body weight lowers G tolerance. caffiene lowers G 

  tolerance.  Heat does too, even when well hydrated. Keep  your training 

  going!  If you have no problem with +6/-4 in the S2 C, that's all you'll need 




  My experience is to fly acro before you exercise if you are doing both on the same day and stay hydrated.  When flying, if you pull hard and see "stars" just call it a day and land because you are too fatigued or dehydrated.  If you feel tired before you fly, just don't fly.  Being younger also helps.


  I used to run 60 miles/week and if I flew after running, even later in the day, it just did not work for me.














Attachement 1: part2.html


© Dr. Günther Eichhorn
Email Guenther Eichhorn