Low Energy in Men Over 40

Reviewed by Dr. Farhan Abdullah, DO

Board-Certified Internal Medicine · IFM Certified Functional Medicine Practitioner

Last clinically reviewed · May 2026

What persistent low energy in men over 40 actually means

If you used to wake up ready to go and now you wake up already tired — if 3 p.m. is a wall — if you're sleeping seven hours and still feel underwater — you're describing the most common chief complaint we hear at intake. The mistake most men make is assuming this is just normal aging or the cost of being busy. It's neither. Energy is downstream of measurable physiology, and at 40 the physiology is no longer doing the work for you that it did at 25.

The five drivers we screen for at intake

Testosterone decline. Total T tracks down ~1% per year after age 30. By the mid-40s many men are clinically hypogonadal and have no idea. TRT directly addresses this when labs and symptoms warrant.

Thyroid dysfunction. Subclinical hypothyroidism is wildly under-diagnosed. We run TSH, free T3, free T4, and reverse T3 — not just TSH — at intake.

Sleep apnea. An estimated 25-30% of middle-aged men have undiagnosed obstructive sleep apnea. Sleep that doesn't restore energy is a workup, not a personal failing.

Insulin resistance and pre-diabetes. Fasting insulin, A1c, and a metabolic panel catch this. Energy crashes after meals are often this in disguise.

Chronic inflammation. hsCRP, ferritin, and homocysteine paint the picture. Inflammation drains energy at the mitochondrial level.

What the workup looks like

First visit is free — on-site testosterone test with same-day results, a body composition scan, and 15 minutes with the medical director. We map your specific energy pattern (morning crash vs. afternoon wall vs. exercise intolerance vs. sleep that doesn't restore) to the most likely physiologic drivers and order the relevant labs. Most patients have answers within two weeks of the first visit, and most start treatment within three weeks.