Be the best father you can be, while staying anabolic and healthy. A new research study that links lower testosterone levels with fatherhood may have caught your attention. The news and blog media are all abuzz with potentially scary reports that becoming a father and greater involvement in childcare activities results in a significant drop in testosterone. Don’t despair! This is not bad news for current or future committed fathers. And don’t turn your back on your family and your partner in favor of higher testosterone and singlehood. This is not the answer. Rather, get the facts, analyze the data, and use your training and supplement program to support optimal health and the best anabolic response.
What Does The Study Say?
The study, just published in the Proceedings of the National Academy of the Sciences
, followed 624 Filipino men aged 21.5 over a 4.5 year period. The sample included a variety of men who were broken into the following groups: 1) men who started out single and became partnered fathers over the study period 2) men who were already partnered fathers at the start of the study 3) men who started and stayed single with no kids 4) men who started out single and became partnered but did not have children over the study period. Researchers measured morning and evening testosterone (T) levels at the start and 4.5 years later.
High T Makes You More Likely To Become A Father
Single non-fathers with higher T levels at the start of the study were more likely to become partnered fathers by the 4.5 year follow up than men with lower T levels at start, indicating that higher T is linked to mating success. This may be because T improves traits related to “mating effort and attractiveness, such as musculature, motivation to win during competition, and pursuit of social dominance.” I’ll get back to this below, but let’s look at what happens to T with the onset of fatherhood first.
There’s a Natural Age-Related Decline in T
The men who became fathers over the study period experienced a decline in T, which was greater than the single non-fathers experienced due to age. Yes, over just 4.5 years the single non-fathers had an average age-related decline in morning T levels of 12 percent and a similar decline in evening levels. Remember that 12 percent number because it’s a useful marker for comparison.
Fatherhood Does Lead to a Decline in T
Men who became newly partnered fathers over the study period experienced the largest decrease in T of all other studied groups with a 26 percent morning decrease and a 34 percent evening decrease. Men who were newly partnered but did not have children over the study period had declines in T that were similar to those of single non-fathers (a 10 percent morning decrease and a 32 percent evening). They had a greater drop in T levels in the evening that was likely due to being partnered. Previous research shows that married and cohabiting men tend to have lower T levels than single men. And, yes, there was more concerning data with the fact that men who were already fathers at the start of the study already had lower T levels. But, the good news is that their levels declined by only a small amount over the study period, likely due to age (7 percent morning decrease and 3 percent evening decrease).
How Do Researchers Account for this Decline in T that Comes with Fatherhood?
Researchers suggest that this natural T decline that comes with fatherhood is an example of how the neuroendocrine system has evolved to support commitment to parenting, which can certainly be viewed as a positive development. Men with higher T have reported feelings of less sympathy and less need to respond to infant cries compared with men with lower T levels. From an evolutionary and survival standpoint it makes sense that men’s hormonal system would adapt when they become fathers in a way that supports the survival of their offspring and the stability of the family unit.
What’s the Effect of Lower T with Fatherhood on Health?
There is actually a positive effect on overall health and longevity from lower lifetime T in men. I call your attention back to the fact that the single men with higher T levels at start were more likely to become partnered fathers, which then led to lower T. Research shows that this is a positive endocrinological adaptation because married men and fathers have lower risk for certain disease and mortality. The study findings “suggest that fathers are likely exposed to lower levels of T throughout much of their prime reproductive years, which could contribute to some of these health differentials.” Specifically, they refer to chronically high T being associated with increased risk of prostate cancer, adverse cholesterol profiles, and risk-taking behaviors such as drug, alcohol use, and promiscuity, which are adverse to health.
This conclusion may surprise you since I have previously reported various studies that low T is linked to poor health in men, particularly diabetes, chronic inflammation, obesity, and the development of metabolic disease. The distinction comes from the definition of “low” versus “high” T—words that are not very helpful in getting to the truth of what all this really means. In the study the average morning T value for all men was 192 pg/ml and at the end of the study it was 162 pg/ml. In comparison, one review in the Journal of Men’s Health
considers “low” T to be below 52 pg/ml, which may be a guideline for starting testosterone therapy.
Nutrient Deficiencies, Toxic Buildup, Obesity Lower T More than Fatherhood
Lead author of the study in question, Lee Gettler, describes a U-shaped curve that describes the link between T levels and health. Low T that is linked to disease is not the drop in T that is associated with fatherhood, but rather the chronically very low T that comes as a result of nutritional deficiencies such as low zinc, omega-3 fatty acids, vitamin D, and magnesium. Another source of low T is buildup of toxins and heavy metals or consumption of meats that contain antibiotics and growth hormones.
How Do T Levels Support Longevity?
To understand how higher T levels over a lifetime may result in poorer health and greater risk of all cause mortality in childless men who remain bachelors throughout their lives, consider the negative side effects associated with anabolic steroid use of testosterone. Doubtless, this is an extreme example because anabolic steroids are synthesized hormones that are administered at extremely high levels, not native testosterone, but the adverse health effects that come with steroid testosterone include negative cardiovascular markers such as elevated cholesterol, high blood pressure, and liver damage to name a few. Similar to with steroid use, men with higher lifetime T have been found to be at greater risk for cardiovascular disease, higher cholesterol, and cancer, including prostate. Gettler suggests that lifetime T levels may be a contributing factor to overall health and longevity differences between married men with children and bachelors. In fact, there are probably a variety of interrelated nutritional, environmental, endocrinological, genetic, and social factors that influence male longevity.
What About Cortisol? It’s Usually Mentioned In Relation to T…
Indeed, I call your attention to cortisol, a hormone known to have adverse health effects that may be just as important in optimal health and the maintenance of muscle mass as T. A second study by the same research group tested both T and cortisol levels (morning and evening) in men who were either single or partnered with children. Results showed that across both subject groups, cortisol and T were positively correlated and single childless men had higher T and cortisol while partnered fathers had lower T and lower cortisol. These tendencies were more pronounced in the evening levels than the morning, which researchers relate to single men being more “mating-oriented” and fathers being more “parenting-oriented.”
Hormones and Focus on Mating
Cortisol and T are thought to support mating efforts by preparing humans for anticipated challenges and increasing arousal and selective attention. Elevated cortisol during short-term interactions with a female relates positively to males’ post-interaction mood rating. Meanwhile there is evidence that elevated T reduces anxiety and motivation to win in competition. In mating-oriented men, the co-elevation of these hormones and behavioral effects will likely result in successful partnering and becoming a father, leading to the natural shift toward parenting and survival.
Long-Term Co-Elevation of T and Cortisol Impedes Health
Researchers suggest there are likely health costs to long-term co-elevation of cortisol and T that would come with prioritizing reproduction over survival and maintenance. Basically, it’s impossible to stay in conquering mode over the course of a lifetime. Just as immediate recovery and longer-term maintenance are necessary elements to a strength training program, similar preservation behaviors are likely best for a happy and healthy life.
Play Time Lowers Cortisol
A third study by the same research group provides additional insight into hormones and fatherhood or what is called the socioendocrinology of male parenting. This study tested cortisol, T, and prolactin (a hormone that has been shown to elevate in animal fathers) in Filipino fathers before and after playing with their toddlers for 30 minutes. T levels didn’t change over the study period, but cortisol declined from before play time to the end of play time and was even lower 30 minutes after. Prolactin also declined.
Across the sample, cortisol decreased significantly when men interacted with their children, and experienced fathers had a sharper decline (46 percent ) than first-time fathers (16 percent decrease). Lower cortisol is likely another male socioendocrinological adaptation that allows for more synchronous and reciprocal interaction with children and with wives. Researchers suggest that the decrease in cortisol could be driven by elevated oxytocin, a hormone that makes you feel good and more affectionate towards a spouse or child. Higher oxytocin combined with lower prolactin and cortisol may indicate an all-around feel-good experience from playing with a child. Previous research into prolactin shows that it declines when male subjects took drugs that activated dopamine circuits, making researchers believe prolactin serves as a peripheral marker of fathers’ dopamine reward centers.
Play Time with Kids Positive for Mating Opportunities
Another element of this study is that researchers recorded the degree that the fathers perceived that their wives approved of their caregiving abilities. Fathers who felt their wives had a more positive opinion of them spent more time with their children and had greater drops in prolactin, which is suggested as a “mating” effort, or a hope that greater spousal approval results in more mating opportunities.
A related issue is the hypothesis that T would decline over the play period because “T may conflict with effective parenting,” but it did not, likely because this would indicate an acute decline. Rather, the chronic decline described in the first study accounted for the need for more nurturing behavior, which made men more sensitive to cues from a child than, for example, to signals from single women. The onset of fatherhood and parenting behavior accounts for the need to shift to more effective parenting and away from an orientation that is strictly focused on mating.
Lower Fatherhood T Does NOT Interfere with Sex Drive
The decline in T in the first study didn’t inhibit mating ability or prevent the men in the study from having more children. The decline in T was subtle enough that it did not interfere with the men’s sex drive, libido, or ability to reproduce. This brings us to the issue of quantifying the drop in T that comes with fatherhood in relation to fluctuations associated with aging, puberty, nutritional deficiencies, and exercise.
Although the percentage decreases in T appear to be large, in reality a 26 percent change is not that
significant and certainly doesn’t equate with having low or unhealthy testosterone levels. Remember that there was an age-related decline of about 12 percent over the 4.5 years in single non-fathers, which actually surprised the researchers as being more than expected. Gettler notes that year-to-year age-related decreases in T are “quite modest” but over longer periods they are more significant, but more research in this area is needed.
Resistance Training May Increase T
For the sake of perspective, one study of 1637 males aged 12 to 90 found that T increases at least three-fold at puberty and reaches peak in the early 20, followed by a gradual decline. Individual levels varied greatly and factors such as body fat percentage and marriage status appeared to be just as important in dictating T levels as age—more body fat meant lower T as did being married. In comparison, there is evidence that resistance training can lead to chronic elevations in T, but to make definitive conclusions more research is needed.
One study of elite weightlifters measured baseline T values that averaged 19.8 nmol/l which increased to 25.1 nmol/l two year later—about a 20 percent increase. The annual mean value of T for the first year was 20.2 nmol/l and increased to an annual mean value of 23.5 for the second year. This study hasn’t been replicated and these are elite lifters, but it is useful to have these numbers for comparison to the 26 percent AM drop in T identified in the first fatherhood study.
Of course, acute increases in T are fairly easily achieved using a hypertrophy-style resistance exercise session with heavy weights and large volume of work. For example, one study of 26-year-old men who performed 10 sets of 10 reps at 75 percent of the 1 RM with 2 minutes rest had acute increases in T of 89 percent at 60-minutes post-training. In the same study, power and strength protocols didn’t result in significant T increases. Another
study in which 24-year-old men did a 30-minute treadmill run at 80 percent of maximal oxygen uptake there was an average acute T increase of 27 percent immediately post-exercise. While short-term T increases are important for muscle building, Gettler said that these increase are not on par with the magnitude of decreases documented in the newly partnered fathers.
What Should I Take Away From These Studies?
Take away an understanding that the endocrine system is finely tuned to help you be a happy, healthy man if you maintain a healthy body composition and have optimal nutrition. A lean body is critical for the best T levels as is resistance training and adequate levels of key nutrients such as zinc, magnesium, omega-3s, and vitamin D. Tips on these nutrients are below.
Higher T levels will help you find a partner and have a child, and caring for the child will allow for the release of feel good hormones. I don’t need to tell you that a family is a vital and rewarding part of life, and it appears that the endocrine system will respond naturally to support this. The natural decrease in T that comes with fatherhood won’t stop you from having more kids or lower your sex drive, and it appears to have overall health benefits. The key is to not let the fatherhood-related decrease turn into a massive age-related drop off due to poor diet, weight gain, or a sedentary lifestyle. And don’t get scared by the media reports that lower T from fatherhood means you’re a wimp or can’t be big, fast, and strong.
What Should I Focus on Nutrition-Wise to Support Healthy T?
s are key for maintaining T production and have been shown to enhance protein synthesis after training, while lowering cortisol levels. They also support a lean body composition and have been shown to decrease inflammation.
is a critical mineral for robust T levels. One study found that zinc supplementation for four weeks led to higher T levels after exhaustive high-intensity exercise than taking either a placebo or a selenium supplement. Researchers note that zinc enhances various mechanisms including elevating the conversion rate of androstenedione to testosterone, and that paired with high-intensity exercise, the body produces T at an even higher rate.
is critical for T production. A new study on the relationship between T and vitamin D found that taking a vitamin D supplement raised T levels in previously deficient men, aged 20-49. Supplementing with 3,332 IUs of vitamin D daily for one year resulted in significant increases in total, free, and bioactive T. There was no change in T levels in a placebo group. Be aware that optimal vitamin D is crucial for muscle strength, power, and force development, possibly because of its relationship with T production!
can increase T levels and it’s critical for physical performance. One study tested a group of sedentary men who received 10 mg/kg of body weight of magnesium a day (Group 1), a group of male tae kwon do athletes taking the same magnesium protocol daily (Group 2), and a group of tae kwon do athletes who did not take magnesium (Group 3). Group 2 had the greatest increases in T levels after tae kwon do practice, followed by Group 3, while Group 1 had the lowest levels (no practice or exercise), indicating that magnesium supplementation raises T levels when combined with exercise.
Branched Chain Amino Acids
, especially leucine-enhanced BCAAs, are a no-brainer for elevating anabolic signaling and upping T.
What About the Best Lifting Protocol for Boosting T?
Quick pointers for boosting T with training are listed below. (For more detail, read The Testosterone Response: Get Anabolic Part 1.
1)Go heavy (85 to 95 percent of the 1 RM) and use large muscle lifts such as Olympic lifts, squats, and deadlifts.
2) Go for high volume. Even with very heavy lifts, you have to have a large volume of work to get anabolic from T.
3) Use short-rest periods in general, but some studies have found that slightly longer rest periods allow for heavier lifts and a larger work volume, resulting in more T response.
4) Complex training with a strength-then-power protocol has been shown to trigger T and give you a better testosterone to cortisol ratio. Sprints are a good choice for raising T.
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