Hormonal changes drive many symptoms of aging—from decreased muscle mass and bone density to reduced energy and cognitive decline. Starting around age 30, your body begins producing less of several critical hormones, with some declining 1-2% annually. Understanding which hormones change and how to optimize them can significantly improve healthspan and quality of life.
Testosterone: The Muscle-Building Hormone
Testosterone levels begin their gradual decline around age 20-30 in men, decreasing approximately 1-3% per year throughout life. This process, termed “andropause,” eventually affects 20% of men over 60 and 30-50% of men over 80. Women also experience testosterone decline, though at levels approximately 10 times lower than men.
The Impact
Testosterone decline contributes to decreased muscle mass and strength, increased body fat (particularly visceral fat), reduced bone density, lower libido, fatigue, and cognitive changes including poor concentration. Men with subnormal testosterone levels show elevated subcutaneous and visceral fat mass compared to those with normal levels.
The Science
Testosterone stimulates protein synthesis (anabolic effect) while inhibiting protein degradation (anti-catabolic effect)—combined, these actions promote muscle growth and maintenance. Testosterone is considered the major promoter of muscle growth and subsequent increase in muscle strength in response to resistance training in men.
The decline occurs through multiple mechanisms: reduced testicular testosterone secretion (primary gonadal decline), changes in the hypothalamic-pituitary-testicular feedback system, and increased folliculostellate cells in the pituitary that influence hormonal cell function.
Estrogen and Progesterone: Beyond Reproductive Health
In women, estrogen and progesterone levels drop abruptly at menopause around age 50 when ovaries cease function. Women lose up to 10% of bone density within the five years after menopause, and 1 in 2 women over 60 will suffer a fracture.
The Consequences
Estrogen is the key hormone protecting heart and bone health in women. Low estrogen levels after menopause cause declines in both. Additional symptoms include hot flashes, mood changes, sleep disturbances, cognitive changes, vaginal dryness, and skin changes including reduced collagen production.
The Mechanism
Estrogen regulates bone remodeling, cardiovascular function, neurotransmitter synthesis, and collagen production. When ovarian estrogen production ceases, the pituitary attempts compensation by producing more follicle-stimulating hormone (FSH), but cannot reverse the estrogen deficit.
Growth Hormone: The Repair and Recovery Hormone
Growth hormone (GH) secretion declines at approximately 1-2% per year after puberty. This age-related decrease, termed “somatopause,” primarily results from reduced amplitude of GH pulses rather than reduced frequency.
The Impact
GH signals the liver to produce insulin-like growth factor-1 (IGF-1), a primary mediator of cellular growth and critical component of post-natal development. GH decline leads to:
- Decreased muscle mass and strength (sarcopenia)
- Increased body fat, particularly abdominal fat
- Reduced bone density
- Slower tissue repair and healing
- Decreased exercise capacity
The Science
The normal nocturnal GH surge is largely sleep-dependent and disappears with sleep deprivation. GH is released primarily during slow-wave sleep (deep sleep), making sleep quality critical for maintaining adequate levels. Mean GH levels are higher during slow-wave sleep compared with other sleep stages.
DHEA: The Precursor Hormone
Dehydroepiandrosterone (DHEA) and its sulfate form (DHEA-S) decline sharply after birth, rise during puberty, peak around the third decade, then gradually decline until death. This “adrenopause” affects both men and women similarly.
The Role
DHEA serves as a precursor for both testosterone and estrogen synthesis in peripheral tissues. It supports:
- Immune function
- Bone density maintenance
- Mood regulation
- Energy production
- Cognitive function
The Decline
Plasma levels of DHEA and DHEA-S sharply decline at birth until age 6-7, rise until approximately the third decade, then gradually decline until death, with a slightly steeper decline in DHEA-S compared to DHEA. The effects of this decline on overall health remain under investigation, though research suggests links to reduced muscle mass, cognitive decline, and decreased immune function.
Cortisol: The Stress Hormone Balance
Unlike the hormones above, cortisol doesn’t necessarily decline with age—instead, its regulation becomes dysregulated. Cortisol release decreases with aging, but blood levels stay about the same. The timing and pattern of cortisol secretion often shift with age.
The Problem
Chronic stress and poor sleep can elevate afternoon and evening cortisol levels while disrupting the normal morning surge. Sleep loss is associated with higher afternoon cortisol, but not morning or 24-hour cortisol.
Why It Matters
Cortisol is the body’s primary catabolic hormone, breaking down muscle protein and promoting fat storage when chronically elevated. Cortisol drives catabolism by activating key muscle protein degradation pathways. It opposes testosterone’s anabolic effects, and when imbalanced, accelerates age-related muscle loss and metabolic dysfunction.
These reciprocal changes imbalance anabolic-catabolic signaling because testosterone and cortisol are respectively the main anabolic and catabolic signals in man.
Resistance Training: The Hormonal Game-Changer
Resistance training powerfully influences multiple age-related hormones simultaneously, making it the single most effective intervention for hormonal health.
Testosterone Effects
Older men participating in a 10-week heavy-resistance training program demonstrated a significant increase in total testosterone in response to exercise stress. Resistance exercise sessions containing high volume and metabolic demand induce an acute testosterone response.
The key: 3 sets of 8-10 repetitions involving major muscle groups (squats, deadlifts, presses) with 90 seconds rest between sets creates sufficient metabolic demand to trigger hormonal responses.
Growth Hormone Boost
In elderly subjects, GH levels increased from 1.00±0.09 to 2.92±0.65ng/mL before training and from 1.50±0.06 to 3.43±0.64ng/mL after 12 weeks of training—representing significant increases.
Strength training can induce growth hormone and testosterone release, regardless of age, though the elderly response does not equal that of the young. Young men showed GH increases from 1.45 to 8.61ng/mL, while elderly showed increases to 3.43ng/mL—still meaningful improvements.
DHEA and Multiple Hormones
Exercise training increases basal levels of testosterone, IGF-1, sex hormone-binding globulin (SHBG), hGH, and DHEA in both males and females over 40 years of age. The effect sizes ranged from small to very large (0.19 < d < 3.37) depending on the specific hormone and training protocol.
The Protocol
For optimal hormonal response:
- Train 3-4 days per week
- Focus on compound movements (squats, deadlifts, rows, presses)
- Use moderate to heavy loads (70-85% of 1-rep max)
- Complete 3-4 sets of 8-10 repetitions
- Rest 60-90 seconds between sets
- Include all major muscle groups per session
Long-term trained elderly males showed testosterone levels of 8.3±1.3ng/mL and GH levels of 1.6±0.7ng/mL compared to sedentary controls with 5.4±1.7ng/mL and 0.8±0.3ng/mL respectively—statistically significant differences.
Prioritize Sleep Quality and Duration
Sleep exerts profound effects on hormonal balance, with even short-term deprivation causing measurable changes.
Testosterone and Sleep
After 1 week of sleep restriction to 5 hours per night, testosterone levels decreased by 10-15%—equivalent to aging 10-15 years. During waking hours, testosterone levels were 16.5nmol/L after sleep restriction versus 18.4nmol/L when rested.
U.S. Army Rangers experienced a 28% reduction in testosterone following sleep deprivation during training, with levels roughly 90% lower than historical data sampled at the same time of day.
The mechanism: Testosterone increase is sleep-dependent, not circadian-dependent, and requires at least 3 hours of sleep with normal architecture.
Growth Hormone and Deep Sleep
The normal nocturnal GH surge disappeared with sleep deprivation and was intensified following sleep recovery. GH is released primarily during slow-wave sleep (stages 3-4), making sleep depth as important as duration.
One night of acute sleep deprivation reduced muscle protein synthesis by 18%, accompanied by a 21% increase in cortisol and a 24% decrease in testosterone.
Cortisol Regulation
Sleep loss is associated with higher afternoon cortisol but not morning or 24-hour cortisol, creating an imbalance in the normal diurnal pattern. The normal cortisol awakening response becomes blunted, while afternoon levels remain chronically elevated.
Sleep Optimization
For hormonal health:
- Aim for 7-9 hours nightly
- Maintain consistent sleep-wake times
- Create a dark, cool environment (65-68°F)
- Avoid screens 2 hours before bed
- Limit caffeine after 2 PM
- Avoid intense exercise within 3 hours of bedtime
The first 3-4 hours of sleep are particularly critical for testosterone and GH secretion.
Optimize Vitamin D Status
Vitamin D influences testosterone production, though the relationship is complex and dose-dependent.
The Association
From the lowest to highest vitamin D quintile, testosterone levels increased from 18.5nmol/L to 20.9nmol/L in multivariate-adjusted analyses, representing a positive dose-response relationship.
Men with vitamin D levels below 25nmol/L had 2.1nmol/L lower total testosterone compared to men with levels above 75nmol/L.
The Evidence
One year of vitamin D supplementation (3,332 IU daily) in vitamin D-deficient men with low testosterone significantly increased total testosterone levels. However, other studies in men with normal baseline testosterone showed no effect, suggesting benefits primarily occur in deficient individuals.
Mendelian randomization analysis provides evidence for biologically plausible causal effects of vitamin D on total testosterone.
The Mechanism
Vitamin D receptors and metabolizing enzymes are expressed in the male reproductive tract. Vitamin D is an important factor in estrogen biosynthesis of both female and male gonads.
Practical Application
- Get blood levels tested (optimal: 75-100nmol/L or 30-40ng/mL)
- Supplement 2,000-4,000 IU daily if deficient
- Get 15-20 minutes sunlight exposure when possible
- Consider higher doses (up to 5,000 IU) for severe deficiency under medical supervision
Note: Benefits appear strongest in those with vitamin D deficiency (<50nmol/L) and low-normal testosterone.
Strategic Nutrition and Supplementation
Healthy Fats for Hormone Production
Dietary fats provide the building blocks for steroid hormone synthesis. Healthy fats high in omega-3s are essential for the body’s ability to create hormones and keep inflammation low, boost metabolism, and promote weight loss.
Prioritize:
- Fatty fish (salmon, mackerel, sardines): 2-3 servings weekly
- Avocados: Rich in monounsaturated fats
- Nuts and seeds: Almonds, walnuts, pumpkin seeds
- Extra virgin olive oil
- Whole eggs
Avoid trans fats and excess omega-6 oils that promote inflammation and may suppress testosterone production.
Protein for Muscle Maintenance
Protein supplements combined with resistance training improved muscle strength and quality of life in men ≥70 years with low testosterone.
Aim for 1.6-2.2g protein per kg body weight daily when resistance training, distributed across 3-4 meals to maximize muscle protein synthesis.
Stress Management for Cortisol Balance
Chronic psychological stress elevates cortisol, which directly suppresses testosterone production and accelerates muscle catabolism.
Evidence-based practices:
- Meditation: 10-20 minutes daily reduces cortisol reactivity
- Deep breathing exercises: 5 minutes before bed improves sleep
- Regular physical activity: Moderate exercise (not excessive) balances cortisol
- Time in nature: Reduces sympathetic nervous system activity
Avoid chronic overtraining, which elevates cortisol and suppresses testosterone despite the acute benefits of exercise.
The Bottom Line
Five key hormones decline with age starting around 30:
- Testosterone drops 1-3% annually in men from age 30, causing muscle loss, increased body fat, and reduced strength. Reverse through heavy resistance training (3-4 sets, 8-10 reps, major muscle groups) and 7-9 hours quality sleep
- Estrogen/progesterone decline abruptly at menopause (~age 50) in women, leading to 10% bone density loss in 5 years and cardiovascular changes. Resistance training and adequate vitamin D support bone health
- Growth hormone decreases 1-2% yearly after puberty, reducing muscle mass and tissue repair capacity. Optimize through resistance training and prioritizing slow-wave sleep quality
- DHEA declines gradually from peak levels in the third decade, affecting immune function and mood. Exercise training increases basal DHEA levels with effect sizes ranging from small to large
- Cortisol regulation becomes dysregulated rather than declining, with chronic stress elevating afternoon levels and disrupting the anabolic-catabolic balance. Manage through 7-9 hours sleep, stress reduction, and avoiding overtraining
Most powerful interventions: Resistance training 3-4x weekly produces significant increases in testosterone, GH, and DHEA regardless of age. Sleep 7-9 hours nightly prevents the 10-15% testosterone drop seen with 5-hour sleep restriction and optimizes GH release during slow-wave sleep. Vitamin D supplementation (2,000-4,000 IU daily) benefits those with deficiency and low testosterone.
Lifestyle factors multiply effects: Combining resistance training, adequate sleep, vitamin D optimization, healthy fats for hormone production, adequate protein (1.6-2.2g/kg), and stress management creates synergistic hormonal benefits far exceeding any single intervention.
If experiencing severe symptoms despite lifestyle optimization—persistent fatigue, significant muscle loss, very low libido, depression—consult an endocrinologist to assess whether hormone replacement therapy is appropriate.
