Overtraining at 45: When Your Workout Becomes the Reason Your Bloods Are Getting Worse

There is a particular type of patient we see regularly at men's health clinics across the UK. He is 44, perhaps 48. He has taken up Hyrox, or signed up for a spring marathon, or started training five evenings a week after a decade on the sofa. His fitness watch says he is smashing it. His blood panel says otherwise: total testosterone drifting down, SHBG climbing, cortisol flattened or erratic, sleep fragmented.

He has not stopped exercising enough. He has started recovering too little — and after 40, that distinction is everything.

The Recovery Deficit Nobody Brags About

Exercise is, in physiological terms, a stressor. Done correctly, the body adapts and emerges stronger. Done excessively — or at the wrong intensity, with insufficient sleep and under-fuelled — the adaptation never arrives. The body simply stays in a state of alarm.

For men in midlife, the consequences concentrate on the hypothalamic-pituitary-gonadal axis. Chronic overtraining, particularly high-volume endurance work, has been shown to suppress luteinising hormone pulsatility, which is the upstream signal that tells the testes to produce testosterone. Simultaneously, sustained cortisol elevation promotes visceral fat storage — which itself converts testosterone to oestrogen via aromatase in adipose tissue. It is a self-reinforcing loop, and it feels like discipline from the inside.

The warning signs are rarely dramatic. They are a resting heart rate that creeps up by five beats. A libido that quietly flatlines. Two weeks of training where no weights feel heavier and no runs feel easier.

Three Ways Midlife Men Sabotage Themselves

The chronic cardio trap. There is nothing wrong with running. There is something wrong with running 50 kilometres a week at a moderately hard effort while working full-time and sleeping six hours. Moderate-to-vigorous aerobic volume beyond your recovery capacity is one of the most reliable non-ageing causes of hormonal decline in men we assess.

Ego lifting without a base. Loading a barbell heavy because you could at 28 — with poor technique, no warm-up structure and no deload weeks — produces injury and systemic inflammation, not strength. Joints at 45 keep different accounts than joints at 25.

Under-recovery as a badge of honour. Training hard seven days a week, treating rest days as weakness. Recovery is when adaptation happens; the session is merely the stimulus.

A Doctor-Formulated Weekly Template

This is the structure we suggest to most male patients over 40 who want training to support their hormones rather than suppress them:

• Monday — Full-body strength (45–60 min). Compound lifts: squat or hinge pattern, press, pull. Heavy enough to matter, controlled enough to stay joint-safe.
• Tuesday — Zone 2 cardio (30–45 min). Conversational pace. You should be able to hold a sentence. This builds aerobic base without cortisol cost.
• Wednesday — Rest or a 20-minute walk. Non-negotiable. Walking is not training; it is circulation.
• Thursday — Strength, lower-body emphasis. Plus 10 minutes of mobility work. Men who skip this end up in our clinics with backs, not hormones, as the presenting complaint.
• Friday — Zone 2 or intervals (30 min). Intervals no more than once weekly, and never the day after a heavy session.
• Saturday — Optional: a long walk, a swim, a bike ride with the family. Movement that doesn't feel like a workout.
• Sunday — Full rest. Sleep in. The hormonal dividend is paid here.

Two rules sit above the schedule. First, protein: roughly 1.6g per kilogram of bodyweight daily, distributed across meals. Second, sleep: under seven hours consistently, and no training plan will out-run the consequences.

The Honest Bottom Line

If your bloods have worsened since you got 'fitter', the exercise is not the problem — the dose is. Train three to four times a week with intent, recover like it is part of the programme, and retest in twelve weeks. In our experience, the men who make this adjustment see their labs, their energy and their training numbers improve together. That is not coincidence. That is physiology finally being given permission to adapt.