Running and/or high intensity training lowers testosterone

joejccva71

It's sad that I have to do this first but,

Disclaimer: I am in no way taking personal shots and/or attacking runners or high endurance athletes.

Also, before runners get defensive and put my picture up on a dart board, read first. Actually READ it. This isn't a "below the belt" shot to runners and/or high endurance trainers. This is to show you why doing TOO MUCH running, high intensity/volume cardio, and/or high intensity/volume endurance training isn't necessarily a good thing. All the time I see people on MFP talking about how they train 6 or 7 days a week running 20 miles and/or 2 hours a day getting ready for their next 5k, 10k or whatever. There's a difference between practicing or training for a race, and running your *kitten* off 6-7 days a week.

Basal reproductive hormonal profiles are altered in endurance trained men.
Hackney AC, Fahrner CL, Gulledge TP.
Source
Endocrine Section, University of North Carolina, Chapel Hill 27599-8700, USA.
Abstract
OBJECTIVE:
The purpose was to examine the basal reproductive hormonal profiles in age-matched groups of endurance trained (ET) and sedentary (SED) men under controlled conditions.
EXPERIMENTAL DESIGN:
Resting basal blood samples were obtained from groups of ET and SED men after a 24-hr control period. Blood specimens were analyzed for testosterone (T), free-testosterone (fT), sex-hormone binding globulin (SHBG), luteinizing hormone (LH), cortisol, and prolactin. The design of the study was retrospective and cross-sectional in nature.
SETTING:
Laboratory setting at the University of North Carolina, North Carolina USA.
PARTICIPANTS:
ET men (n = 53) who had been involved with chronic endurance exercise training for > or = 5 years. SED men (n = 35) were selected of comparable ages and the fact that they had done no formal exercise training.
RESULTS:
Results indicated that the basal T and fT of the ET men were significantly (p < 0.01) lower than that of the SED men. The levels of these hormones in the ET men where in the normal clinical range, but represented only 55% to 85% of those seen in the SED men. For SHBG, LH, cortisol, and prolactin, no significant differences (p > 0.05) were found between the ET and SED men.
CONCLUSIONS:
ET men have lowered basal T and fT levels and this suppression may be related to an alteration in the hypothalamic-pituitary-testicular regulatory axis since the LH of the ET was not elevated. Whether these hormonal changes have any significant beneficial (i.e., protective cardiovascular) or negative (i.e., decrease anabolic-androgenic processes) physiologic consequences remains to be determined.

http://www.ncbi.nlm.nih.gov/pubmed/9763799

Reproducibility of low resting testosterone concentrations in endurance trained men.
Gulledge TP, Hackney AC.
Source
Applied Physiology Laboratory, University of North Carolina, Chapel Hill 27599-8700, USA.
Abstract
Previous reports indicate endurance trained (ET) men have low resting testosterone concentrations without any significant increases in their luteinizing hormone (LH) concentrations. The purpose of this study was to examine the reproducibility of these resting hormonal findings in ET men. Resting blood samples were collected at three separate trials (2 weeks apart) in groups of ET men (n = 15) and age-matched, untrained (UT, n = 13) men. Blood specimens were analyzed for total testosterone, LH, cortisol and prolactin. Results indicated that testosterone was significantly (p < 0.01) lower in ET than UT at each of the three trials. LH, cortisol, and prolactin were not different (p > 0.05) between the groups at any trial. These results confirm earlier findings reported for ET men. Furthermore, the results indicate the resting reproductive hormonal status (i.e., low testosterone) of ET men is reproducible and does not appear to be an artifact of the timing of the blood sampling methodology used.

http://www.ncbi.nlm.nih.gov/pubmed/8817130

Reproductive hormonal profiles of endurance-trained and untrained males.
Hackney AC, Sinning WE, Bruot BC.
Source
Applied Physiology Research Laboratory, Kent State University, Ohio 44242.
Abstract
This study compares the resting reproductive hormonal profiles of untrained (N = 11) and endurance-trained (N = 11) males. Testosterone, free testosterone, estradiol, luteinizing hormone (LH), prolactin, and cortisol were measured by radioimmunoassay in resting blood samples (8 h fast) collected every 60 min for 4 h. The endurance-trained group had been active for (mean +/- SE) 12.4 +/- 6.7 yr, 6.6 +/- 0.2 d.wk-1, 68.5 +/- 4.4 min.d-1, while the untrained group was sedentary. Neither group had histories of hypothalamic-pituitary-testicular disorders. The overall 4 h mean testosterone and free testosterone levels were significantly (P less than 0.05) lower in the trained group (4.99 +/- 0.46 vs 7.25 +/- 0.67 ng.ml-1, and 17.2 +/- 1.4 vs 23.6 +/- 0.6 pg.ml-1, for the trained and untrained groups, respectively). The LH of the endurance-trained group was higher (15.3 +/- 1.9 vs 11.7 +/- 1.2 mIU.ml-1, P = 0.06); however, LH pulse frequency and amplitude did not differ between groups. An enhanced estradiol feedback to the hypothalamus-pituitary could not account for the elevated LH, as estradiol levels were similar in the groups. Prolactin and cortisol levels were normal and did not differ between groups. The results suggested normal hypothalamic-pituitary function existed in the trained subjects, and prolactin and cortisol were not causative factors in the lowered resting testosterone and free testosterone levels. The findings indicate that chronic endurance training lowers testosterone and free testosterone in males possibly by impairing testicular function.

http://www.ncbi.nlm.nih.gov/pubmed/3343919

Relationship between stress hormones and testosterone with prolonged endurance exercise.
Daly W, Seegers CA, Rubin DA, Dobridge JD, Hackney AC.
Source
Endocrine Section, Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina, USA.
Abstract
Previous pharmacological and pathological studies have reported negative relationships between circulating testosterone and certain stress hormones (i.e., cortisol and prolactin) in humans. These relationships have subsequently been used in hypotheses explaining the subclinical resting testosterone levels often found in some endurance-trained males, but as of yet no one has specifically examined these relationships as they relate to exercise. Thus, we examined the relationship between total and free testosterone levels and cortisol, and between total and free testosterone and prolactin following prolonged endurance exercise in trained males. Twenty-two endurance-trained males volunteered to run at 100% of their ventilatory threshold (VT) on a treadmill until volitional fatigue. Blood samples were taken at pre-exercise baseline (B0); volitional fatigue (F0); 30 min (F30), 60 min (F60), and 90 min (F90) into recovery; and at 24 h post-baseline (P24 h). At F0 [mean running time = 84.8 (3.8) min], exercise induced significant changes (P<0.05) from B0 in total testosterone, cortisol and prolactin. All three of these hormones were still significantly elevated at F30; but at F60 only cortisol and prolactin were greater than their respective B0 values. Free testosterone displayed no significant changes from B0 at F0, F30, or the F60 time point. At F90, neither cortisol nor prolactin was significantly different from their B0 values, but total and free testosterone were reduced significantly from B0. Cortisol, total testosterone and free testosterone at P24 h were significantly lower than their respective B0 levels. Negative relationships existed between peak cortisol response (at time F30) versus total testosterone (at F90, r=-0.53, P<0.05; and at P24 h, r=-0.60, P<0.01). There were no significant relationships between prolactin and total or free testosterone. In conclusion, the present findings give credence to the hypothesis suggesting a linkage between the low resting testosterone found in endurance-trained runners and stress hormones, with respect to cortisol.

http://www.ncbi.nlm.nih.gov/pubmed/15618989

And this study will show that MODERATE and/or LOW FREQUENCY training did NOT lower levels of free testosterone in men.

Effect of endurance exercise on resting testosterone levels in sedentary subjects.
Hiruntrakul A, Nanagara R, Emasithi A, Borer KT.
Source
Department of Physiotherapy, Faculty of Associated Medical Science, Khon Kaen University, Thailand. hashir@kku.ac.th
Abstract
OBJECTIVE:
To investigate the effects of moderate-intensity and low frequency exercise on resting serum testosterone and cortisol levels, resting heart rate, and isokinetic strength among healthy sedentary young men.
DESIGN:
A randomized controlled study. Forty sedentary young men aged 18 to 25 years old, pedaled 50 minutes on a bicycle ergometry at 60% of maximal effort once a week for 12 weeks in an exercise group.
OUTCOME MEASURES:
Resting total and free serum testosterone, serum cortisol, anthropometric data, resting heart rate, and isokinetic strength during shoulder and knee extensions.
RESULTS:
Resting serum total and free testosterone, as well as cortisol did not differ significantly between groups. Neither group showed any significant changes in anthropometric data and isokinetic strength at the end of study. However, the resting heart rate of the exercise group reduced significantly after the training (p < 0.05). Also, the isokinetic strength of shoulder and knee significantly increased (p < 0.05).
CONCLUSIONS:
Twelve weeks of moderate-intensity and low frequency training had no effect on resting serum testosterone, but were sufficient to increase aerobic fitness among sedentary young men. The type of exercise training may encourage sedentary individuals to participate regularly in the program on physical activity.

http://www.ncbi.nlm.nih.gov/pubmed/21033613

TL;DR? Conclusion?

Endurance training or high frequency/volume training lowers testosterone which is why marathon runners are pretty weak, and don't look like strength athletes and strength athletes don't do marathon running. ;-)

Also, this is another reason why people tell you not to do alot of cardio BEFORE you strength train. A 5-10 low-intensity warmup is fine, but cardio is meant to be done on an empty stomach no where near your strength training routine. It's totally fine to do it after you train with weights.

Have a nice day.

J

runningxlove

Good thing I'm not a man. :P

Jacwhite22

CarsonRuns

You want to race me?

joejccva71

You want to race me?

Lol really?

jrusso28

Probably the most ridiculous post I have ever read.

:noway:

shannon_121285

Good thing I'm not a man. :P

agreed!

Jacwhite22

Probably the most ridiculous post I have ever read.

:noway:

He did cite some actual studies that back up his point of view......Do you have any that state increased or at least maintained levels of testosterone with large amounts of cardiovascular exercise?

taso42

Probably the most ridiculous post I have ever read.

:noway:

you must've missed the one about the 10lb reams of copy paper vs 10lb dumbbells.

joejccva71

Probably the most ridiculous post I have ever read.

:noway:

Explain please.

MrsCon40

Probably the most ridiculous post I have ever read.

:noway:

Ridiculous? No. It's just science - reproduced my multiple studies.

Opposite what you hope to be true? Apparently, yes.

Besides... what do you mind about reduced fertility if you're endurance training all the time? :bigsmile:

onedayillbeamilf

Good thing I don't have a penis....or run...

onedayillbeamilf

Probably the most ridiculous post I have ever read.

:noway:

you must've missed the one about the 10lb reams of copy paper vs 10lb dumbbells.

^^ This.

CarsonRuns

You want to race me?

Lol really?

No, it was a deflection tactic in attempt to knock you off topic.

But seriously. You quoted a lot of studies, but what's your point? I'm quite sure there are plenty of male endurance athletes that have fathered children, even during training cycles. So, how low is too low?

Edit: spelling

jacksonpt

Interesting.

Do we know how accomplished/trained/fit (for lack of a better word) the ET groups were?

Could body/dietary fat play a role as well or instead of the cardio training? We know fat levels can impact hormone production...

k2quiere

Good thing I don't have a penis....or run...

or want to become bulky

CarsonRuns

Interesting.

Do we know how accomplished/trained/fit (for lack of a better word) the ET groups were?

Could body/dietary fat play a role as well or instead of the cardio training? We know fat levels can impact hormone production...

One of the studies stated that the men were "sedentary".

onedayillbeamilf

Good thing I don't have a penis....or run...

or want to become bulky

That too.

IronmanPanda

That's why I take test.

joejccva71

You want to race me?

Lol really?

No, it was a deflection tactic in attempt to knock you off topic.

But seriously. You quoted a lot of studies, but what's your point? I'm quite sure there are plenty of male endurance athletes that have fathered children, even during training cycles. So, how low is too low?

Edit: spelling

I don't know how low is "too low". There are quite a few men that have ED, and take test booster pills to bring their FT back up to normal levels.

LorinaLynn

I can see this as an excuse some guys would give.

"It's ok, baby... I don't need to wear a condom. I run, so my boys don't swim."

IronmanPanda

I can see this as an excuse some guys would give.

"It's ok, baby... I don't need to wear a condom. I run, so my boys don't swim."

Don't give away my secrets!

joejccva71

I can see this as an excuse some guys would give.

"It's ok, baby... I don't need to wear a condom. I run, so my boys don't swim."

Lol awesome

jrusso28

Probably the most ridiculous post I have ever read.

:noway:

Ridiculous? No. It's just science - reproduced my multiple studies.

Opposite what you hope to be true? Apparently, yes.

Besides... what do you mind about reduced fertility if you're endurance training all the time? :bigsmile:

Because you can find a negative for pretty much any activity you want.
Not certain your motivation for even doing the research and posting this information in the first place.
Running marathons or competing in any number of endurance events is a major accomplishment and a tribute to their physical fitness and dedication to what they do.

Your post is as ridiculous as other posts similarly knocking Body Building and its "negative side affects"
Heart attacks at a young age
Low Self esteem
Kidney failure
Liver disease
Long term testicular failure
Depression
Huge suicide risk
Life threatening infections
Problems with aggression

UsedToBeHusky

I would have liked to have seen in these studies how running effects estrogen and testosterone production in both men and women.

jacksonpt

Interesting.

Do we know how accomplished/trained/fit (for lack of a better word) the ET groups were?

Could body/dietary fat play a role as well or instead of the cardio training? We know fat levels can impact hormone production...

One of the studies stated that the men were "sedentary".

Right, 1 study says it took 40 sedentary people and had them pedal. That's not a study on endurance trained athletes, that's a study on cardio exercise. 3 looked specifically at endurance trained athletes, and at least one of them compared them to a sedentary group. I'm wondering what "endurance trained" means. Are they talking about elite level athletes (competitive ironmen, for example), or are they looking at more "regular" people (like me) who enjoy endurance activities in their spare time, around full time jobs, kids/families, etc.?

kimchi84

lol

joejccva71

I would have liked to have seen in these studies how running effects estrogen and testosterone production in both men and women.

Couldn't find concrete info on how running or high endurance training affects women.

UsedToBeHusky

Wow, look at that ! One of the side affects is "Long Term Testicular failure !!
OMG - you better quit now before your penis falls off.....

Get a life!

The hostility really isn't necessary is it. Scientific studies are meant to further our understanding. The OP didn't post this to tell people that running is wrong. He very clearly explained the body differences that result from two different types of training. The studies are too narrow to say for sure, but this type of study could create a natural way to treat hormonal imbalances. I found the study insightful, but I found your response to be immature.

onedayillbeamilf

Probably the most ridiculous post I have ever read.

:noway:

Ridiculous? No. It's just science - reproduced my multiple studies.

Opposite what you hope to be true? Apparently, yes.

Besides... what do you mind about reduced fertility if you're endurance training all the time? :bigsmile:

Because you can find a negative for pretty much any activity you want.
Not certain your motivation for even doing the research and posting this information in the first place.
Running marathons or competing in any number of endurance events is a major accomplishment and a tribute to their physical fitness and dedication to what they do.

Your post is as ridiculous as other posts similarly knocking Body Building and its "negative side affects"
Heart attacks at a young age
Low Self esteem
Kidney failure
Liver disease
Long term testicular failure
Depression
Huge suicide risk
Life threatening infections
Problems with aggression

Wow, look at that ! One of the side affects is "Long Term Testicular failure !!
OMG - you better quit now before your penis falls off.....

Get a life!

*pats head* There there. No need to get upset. :flowerforyou:

joejccva71

Interesting.

Do we know how accomplished/trained/fit (for lack of a better word) the ET groups were?

Could body/dietary fat play a role as well or instead of the cardio training? We know fat levels can impact hormone production...

One of the studies stated that the men were "sedentary".

Right, 1 study says it took 40 sedentary people and had them pedal. That's not a study on endurance trained athletes, that's a study on cardio exercise. 3 looked specifically at endurance trained athletes, and at least one of them compared them to a sedentary group. I'm wondering what "endurance trained" means. Are they talking about elite level athletes (competitive ironmen, for example), or are they looking at more "regular" people (like me) who enjoy endurance activities in their spare time, around full time jobs, kids/families, etc.?

I'm pretty sure it depends on your volume/frequency levels when it comes to your endurance training bro.