.svg)
.svg)
Your testosterone levels are the result of countless forces acting on your health — promoting or impairing the production of the male hormone. Factors like your weight, body mass index (BMI), age, or comorbidities (like diabetes) are all important players in the testosterone equation.
While specific facts about testosterone are well-known, others remain surprising revelations — especially if research has previously been inconclusive.
With that being said, the decline of testosterone levels with age has been well-documented, with comorbidities able to accelerate this decline further. We also know about diurnal changes in testosterone (fluctuations in healthy testosterone levels during the day) as levels are usually highest in the mornings and gradually decrease during daytime hours.
But what about seasonal changes? Can environmental factors like temperature, humidity, and sun exposure really impact your testosterone levels? Let’s find out.
What Are Normal Testosterone Levels?
Healthy testosterone levels are highly individualized values that will depend on an array of contributing factors — with age marking the most significant one.
While the American Urological Association (AUA) has established that 300 ng/dL (nanograms per deciliter) is a solid cut-off for normal testosterone levels, researchers raise concern that age-indiscriminate guidelines could be misleading.
Young men generally should have a much higher reference range when compared to older men, with total serum testosterone levels expected to decline about 1.6% every year.
Are Seasonal Variations in Testosterone Levels a Myth?
Several studies have looked into a potential link between testosterone levels and seasonal changes, suggesting that environmental factors may need to be considered when investigating the possibility of low testosterone. Here’s why.
What Did Research Find?
While a multitude of trials have been conducted to understand the correlation between testosterone levels and seasonal fluctuations, some of the results obtained are conflicting. Nonetheless, many studies were performed on a large scale and suggest that certain seasonal parameters could potentially play a role in testosterone levels.
One study that investigated 80 individuals between age 20 and 35 found that testosterone levels were within normal limits in winter and summer, however, testosterone levels were lower during the colder months.
These results were supported by a large cross-sectional study where the medical records from 27,328 men were investigated. It suggested that seasonal variations should be considered in clinical practice as significant changes in both total and bioavailable testosterone levels were found — with testosterone levels peaking in the summer months and crashing in the winter months.
Another trial examined testosterone levels in different climates and looked into individuals living in Pittsburgh versus Miami. While researchers found distinct hormone levels in each of these geographic regions, seasonal variations within the Miami group and Pittsburgh group themselves were not statistically significant.
Yet another study conducted on 8,400 police officers in Seoul, South Korea found lower testosterone levels during the spring and summer months and an increase in the male hormone during the fall and winter months. However, it’s noteworthy that every individual was only assessed once during the study period, potentially limiting the results as no individual summer-winter comparisons could be drawn.
While some findings have been inconsistent, there’s a trend toward the theory that testosterone levels increase in the summer months and decrease in the winter — which led to further hypotheses.
A review suggested that exploring other factors is critical in determining HOW changes in testosterone levels come about. These factors are more significant during certain seasons and could be key contributors to seasonal variations in testosterone levels — including vitamin D levels and sun exposure, as well as physical activity and the wake-sleep cycle.
Factors That Can Impact Testosterone Levels During Seasonal Changes
When we think of summer, we think of sunshine and outdoor adventures — hiking winding trails, swimming in the blue ocean, and jogging in your favorite park. Exploring what these activities and habits mean for your lifestyle can be a key variable in determining if seasonal changes can impact your testosterone levels. But what does that mean exactly?
(1) Physical Activity
Research shows that testosterone levels rise after exercise, with physical activity offering countless health benefits. With mild to warm temperatures in many regions of the world during the summer months, it’s not far-fetched to assume that people would be more active — unconsciously fueling the production of in-house testosterone.
According to a review of seasonal behaviors, 23 out of 30 studies confirmed the volume of physical activity was much greater in the summer months.
(2) Exposure to Sunlight
Another important factor worth exploring is the exposure to sunlight — because if there was a link between hours of sun exposure and testosterone levels, the summer months would have a clear upper hand and boost testosterone synthesis.
The key is, in fact, vitamin D, which you can obtain naturally through daily sun exposure to your skin. A study in overweight men, for example, found that vitamin D led to a remarkable increase in total testosterone, bioavailable, and free testosterone.
(3) BMI & Waist Circumference
It’s hard to maintain healthy testosterone levels if your BMI is on an upward curve. However, a healthy body weight is imperative for your hormone levels, with research confirming that obesity adversely affects testosterone.
Due to a reduced level of physical activity in the winter months and poorer dietary patterns, you’re more likely to gain weight in the winter months — which, in turn, makes increases in your BMI, and testosterone, more likely to occur in the cold season.
Maintain Healthy Testosterone Levels, No Matter the Season
Every season brings about new temperatures and environmental changes that your body will need to adjust to. Some of these changes can dictate a new day-to-day routine and affect both your activity level and eating habits — indirectly impacting your testosterone levels behind the scenes.
While research may have only determined a potential trend thus far, know that countless outside factors, comorbidities, and habits will influence your testosterone levels.
But if your goal is to keep healthy testosterone levels, strive to maintain healthy habits year-round, no matter the season.
Intrigued to learn more about environmental factors and potential fluctuations in your testosterone levels? Sign up for our newsletter to learn more.
