The Complete Guide to Testosterone Optimization — Part 2: Training and Sleep

Part 1 laid the nutritional groundwork: energy availability, macronutrient balance, key micronutrients, gut health, and the foods and substances worth minimizing. But food is just raw material. Training tells your body what to build, and sleep is when most of the building actually happens. These two levers are deeply connected, and getting them right compounds everything else in this series.

Resistance Training: The Real Mechanism

You'll find no shortage of content telling you to "lift heavy for testosterone." That's not wrong, but the reasoning usually is. The acute testosterone spike you get after a heavy squat session has been the go-to justification for decades, but the evidence increasingly suggests that transient post-exercise hormonal elevations don't meaningfully drive long-term muscle growth or hormonal adaptation. A 2012 study by West et al. found no relationship between acute hormonal responses and training outcomes over 15 weeks.

So why does resistance training still matter so much for testosterone? Because the chronic, downstream effects are what actually move the needle: improved insulin sensitivity, reduced visceral fat, better sleep quality, increased lean mass, and a more favorable metabolic environment overall. In other words, resistance training doesn't boost testosterone because of what happens in the 30 minutes after your workout. It does so because of what it does to your body over months and years.

Training Principles

Focus on compound movements that recruit large muscle groups: squats, deadlifts, bench press, overhead press, rows, and pull-ups. These provide the most stimulus per unit of time.

Train with sufficient intensity. Working in the 75–90% of one-rep max range for 3–6 repetitions builds strength and neuromuscular efficiency. Including work in the 8–12 rep range for hypertrophy and the 12–20 range for metabolic stress creates a well-rounded stimulus. You don't need to pick one approach; rotating across these ranges over time is ideal.

Train 3–5 days per week with adequate recovery between sessions. Progressive overload is essential: gradually increase weight, reps, or sets over time. Without progressive overload, adaptation stalls.

On workout duration: keep sessions focused and efficient. There's a persistent claim in fitness culture that training beyond 60–90 minutes causes excessive cortisol elevation, but the evidence for a hard cutoff is weak. Cortisol does rise with training duration, and very long sessions can accumulate unnecessary fatigue, but post-exercise cortisol is part of the normal adaptive response. The real issue is total training volume relative to recovery capacity, not the clock. If your sessions are productive and you're recovering well, don't stress about the timer.

Finding Your Structure

There's no single "best" training split. What matters is that you hit all major movement patterns (push, pull, squat, hinge) with adequate frequency and intensity across the week. A 4-day upper/lower split, a 3-day full-body program, or a 5-day push/pull/legs rotation can all work depending on your schedule, experience level, and recovery capacity. A favorite of mine is a 5-day push/pull/legs/upper/lower rotation, provided recovery is adequate.

Bottom line, the best program is the one you'll actually follow consistently. If you're unsure where to start, three days per week of full-body compound training is a proven entry point.

Sprint Training and High-Intensity Intervals

Short bursts of maximal effort (10–30 seconds) followed by rest periods are an efficient way to improve cardiovascular capacity and insulin sensitivity, both of which support a favorable hormonal environment over time. You'll often see sprints justified by the acute growth hormone spike they produce, but the same logic applies as with the testosterone spike from resistance training: transient hormonal elevations are not what drive long-term adaptation. The chronic effects on metabolic health are. Once or twice weekly, perform 5–10 sprints at 90–95% effort with 2–3 minutes rest between efforts. This can be running, cycling, rowing, or sled pushes. The key is genuine intensity during work periods.

A note of caution: sprints are high-impact and carry injury risk, especially for men who are deconditioned or carrying excess weight. Build up gradually. Cycling or rowing are lower-impact alternatives that deliver similar metabolic benefits.

Strategic Cardiovascular Training

Regular cardiovascular exercise has clear health benefits, but excessive steady-state cardio can work against testosterone optimization, particularly when combined with a caloric deficit or insufficient recovery. The mechanism is straightforward: chronic overtraining elevates cortisol and suppresses the HPG axis.

Limit dedicated steady-state cardio to 2–3 sessions of 30–45 minutes weekly at conversational pace (Zone 2). Walking is ideal and underrated. It reduces stress, supports insulin sensitivity, and doesn't generate the recovery demands that interfere with resistance training.

Movement Throughout the Day

Sedentary behavior independent of structured exercise is metabolically harmful. Break up sitting every 30–60 minutes. Use a standing desk, take walking meetings, and aim for 8,000–12,000 steps daily. This supports insulin sensitivity, which is directly relevant to testosterone metabolism. You can't out-train eight hours of sitting.

Sleep: Where Testosterone Is Made

Sleep is when the body produces the majority of its testosterone, primarily during deep sleep phases in the first half of the night. One week of restricted sleep (5 hours per night) has been shown to reduce daytime testosterone by 10–15%, with chronic sleep deprivation producing hormonal profiles resembling those of men significantly older. The exact magnitude varies between studies, but the direction is consistent: less sleep, less testosterone.

Sleep Duration and Quality

Target 7–9 hours of quality sleep nightly. Individual needs vary, but most men function optimally with 7.5–8.5 hours. Sleep debt accumulates and can't be fully compensated by weekend catch-up sleep, but the latter is better than nothing. That said, an occasional poor night of sleep isn't going to kill you, and some people tend to overemphasize sleep to an almost neurotic degree.

Going to bed earlier rather than later generally provides better hormonal benefits, since slow-wave sleep predominates in the first half of the night. That said, your chronotype matters. Genuine night owls may sleep better and produce more deep sleep with a later bedtime, provided they actually get the hours in and aren't fighting their natural rhythm.

For men who consistently fall short on nighttime sleep, a brief daytime nap (20–30 minutes, before 2 PM) can reduce cortisol and support recovery. It's not a substitute for fixing your nighttime sleep, but it's a useful tool when life doesn't cooperate.

Circadian Rhythm Alignment

The master circadian clock in the suprachiasmatic nucleus regulates hormone production, including testosterone. Disrupting circadian rhythms through irregular sleep schedules, shift work, or excessive artificial light exposure suppresses testosterone.

Morning light is non-negotiable. You'll often hear that you need to get outside within 30 minutes of waking, parroted across podcasts and social media as if it's a golden rule. It isn't. The 30-minute figure is a practitioner heuristic, not a finding from clinical research. What the evidence actually supports is that light exposure within the first hour or two of waking provides circadian anchoring benefits. Sooner is better, but consistency matters more than perfect timing. Aim for 10–15 minutes outside, even on overcast days, since outdoor light is substantially brighter than typical indoor lighting and powerful enough to anchor your circadian rhythm. If you wake before sunrise, which is a reality for much of the year in northern latitudes, get outside as soon as natural light is available, or use a bright light therapy lamp in the meantime. The goal is a consistent signal that anchors your hormonal day-night cycle and improves nighttime melatonin production.

Dim lights 2–3 hours before bed. Use amber-tinted blue-blocking glasses if viewing screens. Blue light suppresses melatonin and shifts circadian rhythm later, though recent research suggests the effect is smaller than commonly believed in real-world conditions. Still worth taking seriously, particularly if you struggle with sleep onset.

Optimize your sleep environment. Keep your bedroom cool (15.5–19.5°C / 60–67°F), completely dark (blackout curtains or an eye mask), and quiet (or experiment with different types of noise). The natural drop in core body temperature is part of how the brain initiates sleep, and a cooler room supports that process.

Maintain consistent timing. Keep sleep and wake times within a 30–60 minute window, even on weekends. Variability in sleep timing is independently associated with poor metabolic health.

Watch your stimulants and depressants. Avoid caffeine after 2 PM. It has a half-life of 4–6 hours on average, though individual metabolism varies significantly based on genetics. Slow metabolizers may need to cut off earlier. Even if you can fall asleep with caffeine in your system, it impairs sleep quality and architecture. Avoid alcohol within 3 hours of bed: it may help you fall asleep faster, but it fragments sleep and suppresses REM. Any amount affects sleep architecture, and as covered in Part 1, no alcohol is always best.

Sleep Hygiene Practices

Establish a wind-down routine 30–60 minutes before bed. The goal is parasympathetic activation, not entertainment. Anything that keeps your nervous system in fight-or-flight mode (work, intense conversations, scrolling, action movies) is going to make sleep onset harder regardless of how tired you feel, though exceptions do exist. What works varies by person. The point is to give your nervous system a clear signal that the day is done.

Keep electronic devices out of the bedroom if possible. If using an alarm, place your phone across the room to avoid nighttime checking.

On the supplement side, L-theanine (200–600 mg) or glycine (3–5 grams) taken 30–60 minutes before bed can meaningfully support sleep quality. Apigenin (50 mg, derived from chamomile) is another reasonable option with decent evidence for sedation. Phosphatidylserine (300–600 mg) can help blunt elevated evening cortisol and is particularly useful for men whose sleep is disrupted by stress. For men dealing with elevated cortisol and stress-driven insomnia, ashwagandha (300–600 mg of a standardized extract like KSM-66) taken in the evening can help, though we'll cover stress-related interventions in more depth in Part 3.

If you're already supplementing magnesium glycinate as discussed in Part 1, you're getting both magnesium and glycine in one, which is another reason that form is worth choosing.

The Training-Sleep Connection

These two domains are deeply intertwined. Training improves sleep quality, particularly deep sleep, which is when testosterone production peaks. Sleep, in turn, drives recovery and adaptation from training. Disrupting one undermines the other.

This is why the combination of consistent resistance training and solid sleep habits is arguably the single most impactful intervention for testosterone optimization. Nutrition provides the inputs. Training and sleep provide the signal and the environment for the body to actually produce and utilize testosterone.

The practical implication: if you're only going to focus on two things from this entire series, make it consistent resistance training a few times per week and 7–9 hours of quality sleep.

In Part 3, we shift from the physical to the psychological: how chronic stress, cortisol, and your sense of purpose directly shape your hormonal profile.