Did men really have better testosterone in grandpa's day?

What does this Instagram video claim?

Mark Stiles argues that previous generations had better testosterone because they did manual labor, ate simple unprocessed foods, and handled stress without modern comforts. He suggests returning to this lifestyle will optimize testosterone levels naturally.

The post taps into nostalgia about "how men used to live" while promoting testosterone optimization. It's the classic appeal to tradition fallacy wrapped in fitness influencer packaging.

Are testosterone levels actually declining?

Yes, multiple studies confirm testosterone levels have dropped significantly over decades. Travison et al. (Journal of Clinical Endocrinology & Metabolism, 2007) found testosterone declined 1% per year from 1987-2004, independent of aging and health factors.

More recent data from Lokeshwar et al. (World Journal of Men's Health, 2021) showed total testosterone decreased from 605.39 ng/dL in 1999 to 567.44 ng/dL in 2016. That's a 6.2% drop in less than two decades.

So Stiles gets this part right. Testosterone levels are genuinely falling across populations.

Does manual labor actually boost testosterone?

The exercise connection is real, but Stiles oversimplifies it. Resistance training does increase testosterone acutely and chronically, according to Kraemer & Ratamess (Sports Medicine, 2005). Heavy compound movements produce the biggest hormonal responses.

But chronic overwork and physical stress can tank testosterone. Construction workers and manual laborers often have lower testosterone due to chronic fatigue and inadequate recovery. The Whitehall II study found job strain correlated with reduced testosterone in men.

His grandfather probably wasn't doing optimized strength training. He was likely doing repetitive, exhausting labor that modern research suggests hurts hormone production.

What about the diet claims?

This gets messier. Dietary fat does support testosterone production. Reed et al. (American Journal of Clinical Nutrition, 1987) showed that reducing fat from 40% to 25% of calories dropped testosterone by 12%.

But the "real food" narrative ignores major problems with historical diets. Nutritional deficiencies were common. Zinc deficiency, which directly impacts testosterone, was widespread before food fortification.

Modern processed foods aren't great, but access to consistent protein, vitamins, and minerals is better now than in grandpa's era. The difference likely comes from obesity rates, not food processing per se.

What should you actually know about testosterone?

The real culprits behind declining testosterone are obesity, sedentary lifestyles, sleep deprivation, and environmental factors like endocrine disruptors. Corona et al. (Reviews in Endocrine and Metabolic Disorders, 2016) identified obesity as the strongest predictor of low testosterone in young men.

Sleep matters more than Stiles acknowledges. Leproult & Van Cauter (JAMA, 2011) found that one week of sleep restriction dropped testosterone by 10-15% in healthy young men.

If you're concerned about testosterone, focus on maintaining healthy body weight, getting 7-8 hours of quality sleep, doing resistance training, and managing chronic stress. The nostalgic lifestyle approach misses the actual science.