THE SCIENCE
THE PROBLEM
Sperm health is collapsing. Nobody is paying attention.
Total sperm counts have fallen by more than 60% globally since the 1970s. The rate of decline is accelerating, more than doubling since 2000. If these trends continue unchecked, some researchers have warned that male fertility could reach critically low levels within decades.
This is not a fringe concern. It is one of the most significant public health trends of the century, confirmed by a landmark meta-analysis covering data from 53 countries across six continents. (Levine et al., Human Reproduction Update, 2023)
- 62%decline in total sperm count.
- Mean sperm concentration among unselected men fell from 101 million/ml to 49 million/ml between 1973 and 2018. The annual rate of decline has more than doubled since 2000.
- 50%of infertility involves male factor.
- A male factor is involved in approximately half of all couples experiencing infertility. Yet women have 10× more support in the market than men, and most men never test until they are deep into a fertility journey.
- 55%of countries below replacement fertility.
- More than half of all countries (home to over two-thirds of the global population) now have fertility rates below replacement level. Governments are beginning to treat this as a policy priority. Almost none address male factor specifically.
Levine et al., Human Reproduction Update, 2023
WHO Infertility factsheet; Agarwal et al., The Lancet, 2021
UN World Fertility Report, 2024
The causes are environmental and behavioural: endocrine disruptors in food and water, rising obesity, sedentary lifestyles, heat exposure from laptops and tight clothing, chronic stress, poor sleep, and increasing alcohol consumption. These are not fixed conditions. They are modifiable. But modification requires measurement; and for men, no sufficient measurement system exists.
Watch:
“For most of a man's life from adolescence, his sperm is framed as a threat. Society invests enormous energy engineering the suppression of male fertility and almost no effort restoring it.”
THE CONSEQUENCE
Sperm is the missing metric in men's health.
Most people assume sperm health only matters when you are trying to conceive. That assumption is wrong.
Sperm quality is one of the most sensitive biological indicators a man has. It reflects testosterone levels, metabolic function, cardiovascular fitness, sleep quality, stress load, and toxic exposure. When something drifts in a man's biology, sperm often shows it first; before a blood panel, before symptoms, before a diagnosis.
- Testosterone and hormonal balance.
- Sperm production is driven by the hypothalamic-pituitary-gonadal axis, which is the same hormonal system that regulates testosterone, libido, energy, and mood. A decline in sperm parameters frequently signals broader hormonal disruption.
- Metabolic and cardiovascular health.
- Research has linked poor semen quality to reduced life expectancy and higher rates of chronic disease, including cardiovascular conditions. Men with abnormal semen parameters show significantly higher mortality rates across a wide range of causes. Sperm health is increasingly recognised as a proxy for systemic metabolic function.
- Oxidative stress and cellular damage.
- Sperm cells are highly vulnerable to oxidative stress: an imbalance between free radicals and the body's ability to neutralise them. Elevated oxidative stress damages sperm DNA and is linked to broader ageing processes across the body.
- Environmental and lifestyle exposure.
- Sperm reflects the cumulative impact of a man's daily environment and behaviour in ways most other biomarkers do not: heat, alcohol, poor diet, disrupted sleep, endocrine-disrupting chemicals, and more.
Eisenberg et al., Sperm Count and Hypogonadism as Markers of General Male Health, 2019
Jensen et al., American Journal of Epidemiology, 2009; Eisenberg et al., Human Reproduction, 2014
Tremellen, Human Reproduction Update, 2008
Durairajanayagam, Arab Journal of Urology, 2018; Pizzol et al., International Journal of Molecular Sciences, 2021
The 70-day cycle
Sperm is not a fixed asset. It is rebuilt roughly every 70 days through spermatogenesis: the biological process by which spermatogonial stem cells differentiate into mature spermatozoa, followed by 10–14 days of epididymal transit and maturation. Every generation of sperm is shaped by what a man does during that window: his sleep, his diet, his exercise, his alcohol intake, his stress, his heat exposure.
This means sperm health is not a final verdict in most cases. It is a cycle. And every cycle is an opportunity to improve.
This biological reality is the foundation of everything LOAD.® is built on. It is why daily tracking matters. It is why behaviour change works. And it is why a single test tells you almost nothing, but a system that tracks across cycles tells you everything.
THE SOLUTION
This is where LOAD.® comes in.
Male reproductive health has been invisible for as long as it has existed, simply because the infrastructure to make it known has never been built.
There is no standard metric for sperm health across the industry. No daily measurement. No feedback loop. No system that connects what a man does today to what his biology looks like in 70 days.
LOAD.® exists to change that.
The Sperm Health Score®
The Sperm Health Score® is a composite daily metric from 0 to 100 that models semen quality across five WHO-recognised parameters: concentration, motility, progressive motility, morphology, and volume. It is a structured predictive model built on established dose-response relationships between modifiable lifestyle factors and semen parameters, and designed to become increasingly personalised to each user's individual biology as their data accumulates.
The principle that semen quality can be predicted from lifestyle variables is supported by research stretching back well over a decade. Girela et al. (2013) demonstrated that neural networks could predict sperm concentration from lifestyle data with up to 86% accuracy. Ma et al. (2022) showed that ten modifiable factors could predict concentration, motility, and DNA fragmentation across 5,109 men. Aykaç et al. (2024) predicted specific diagnostic categories from lifestyle data alone. Separately, meta-analyses have quantified the individual relationships between diet, alcohol, sleep, exercise, obesity, and specific semen parameters. These relationships are not hypothetical. They are quantified, replicated, and directional.
SHS® applies this evidence continuously. A rules-based layer maps daily behavioural inputs against their documented relationships with each WHO semen parameter, weighted by strength of the supporting evidence. A machine learning layer, trained on LOAD.®'s growing dataset and governed by the scientific advisory board, identifies nonlinear interactions and individual response profiles that emerge.
A single semen analysis is inherently limited. Sperm concentration can fluctuate 30% or more between samples taken days apart, and the WHO recommends at least two samples before drawing clinical conclusions. Our SHS® contextualises test results within months and years of behavioural data.
“What we cannot see, we cannot change. That is the foundational truth behind what we're building. It's unacceptable that in the 21st century something as important as sperm health should be left to luck. That's the model we will replace.”
- Alcohol
“Habitual alcohol consumption is associated with reduced semen volume, sperm count, and percentage of normal morphology in a dose-dependent manner.”
Jensen TK et al., BMJ Open, 2014
Read full article - Stress
“Psychological stress is significantly associated with decreased sperm concentration and motility, and increased proportion of abnormal morphology.”
Nargund VH, Nature Reviews Urology, 2015
Read full article - Heat exposure
“Scrotal hyperthermia from laptops, saunas, tight clothing and prolonged sitting is a significant modifiable risk factor for male infertility.”
Durairajanayagam D, Agarwal A & Ong C, Reproductive BioMedicine Online, 2015
Read full article - Sleep
“Both short and long sleep duration are associated with lower total sperm count and reduced sperm survival rates.”
Chen Q et al., Sleep, 2016
Read full article - Exercise
“Moderate physical activity is positively associated with semen quality, while sedentary behaviour and extreme exercise show negative effects.”
Gaskins AJ et al., British Journal of Sports Medicine, 2013
Read full article - Diet
“A healthy dietary pattern rich in fruits, vegetables, fish and whole grains is associated with better semen quality parameters.”
Salas-Huetos A, Bulló M & Salas-Salvadó J, Human Reproduction Update, 2017
Read full article - Phone exposure
“Mobile phone exposure is associated with reduced sperm motility and viability, with effects linked to duration and proximity of use.”
Adams JA et al., Environment International, 2014
Read full article - Sperm cycle
“The full cycle of spermatogenesis takes approximately 64–74 days, meaning lifestyle changes today affect sperm quality roughly 10 weeks later.”
Amann RP, Journal of Andrology, 2008
Read full article - Sperm count
“Meta-analysis of 223 studies showing sperm counts in men declined over 50% between 1973 and 2018, with the rate of decline accelerating.”
Levine H et al., Human Reproduction Update, 2023
Read full article - Male infertility
“Male factor is a primary or contributing cause in approximately 50% of couples experiencing infertility.”
Agarwal A et al., The Lancet, 2021
Read full article - Semen quality
“Mortality decreased as sperm concentration increased up to 40 million/ml, across a wide range of diseases, suggesting semen quality is a fundamental biomarker of overall male health.”
Jensen TK et al., American Journal of Epidemiology, 2009
Read full article - Life expectancy
“Men with two or more abnormal semen parameters had a 2.3-fold higher risk of death compared with men with normal semen.”
Eisenberg ML et al., Human Reproduction, 2014
Read full article - Oxidative stress
“Oxidative stress is implicated in 30–80% of male infertility cases, damaging sperm DNA, lipid membranes and proteins through reactive oxygen species.”
Tremellen K, Human Reproduction Update, 2008
Read full article - Lifestyle
“Heat, alcohol, diet, sleep, obesity, smoking and environmental chemicals are all modifiable lifestyle factors with documented effects on semen parameters.”
Durairajanayagam D, Arab Journal of Urology, 2018
Read full article - Epigenetics
“Paternal lifestyle and environmental exposures (diet, obesity, smoking, endocrine-disrupting chemicals, stress) alter sperm epigenetic marks, influencing fertilising ability, embryo development and offspring health.”
Akhatova A, Jones C, Coward K & Yeste M, Clinical Epigenetics, 2025
Read full article - Egg activation
“PLCzeta is the sperm-specific protein responsible for activating the egg at fertilisation. Defects in PLCzeta cause a form of male infertility undetectable by routine clinical tests.”
Coward K et al., Reproduction, 2022
Read full article - ICSI failure
“When sperm fails to activate the egg properly, it can result in total fertilisation failure and recurrent ICSI failure, conditions that require targeted molecular diagnosis.”
Meng-Yao L et al. (incl. Coward K), Human Reproduction Open, 2022
Read full article - Supplements
“Lactolycopene supplementation for 12 weeks improved the proportion of fast progressive sperm by approximately 40% and improved sperm morphology in healthy males.”
Williams EA, Parker M, Robinson A, Pither S & Pacey AA, European Journal of Nutrition, 2020
Read full article - Poor semen
“Specific modifiable lifestyle and occupational factors are significantly associated with poor semen quality in a large multi-centre UK population.”
Pacey AA et al., Human Reproduction, 2012
Read full article - Environment
“Occupational exposure to glycol ethers, commonly found in paints, is associated with low motile sperm count and abnormal sperm morphology.”
Cherry N & Pacey AA et al., Systems Biology in Reproductive Medicine, 2014
Read full article - Diet
“Both low-energy diet and brief dietary intervention improve sperm motility in men with obesity, demonstrating that lifestyle changes directly improve sperm parameters.”
Jayasena CN et al., Journal of Clinical Endocrinology & Metabolism, 2024
Read full article - Testosterone
“Health optimisation remains the gold-standard management strategy for functional male hypogonadism, where low testosterone is driven by obesity, type 2 diabetes and ageing rather than irreversible HPT pathology.”
Jayasena CN et al., The Lancet Diabetes & Endocrinology, 2024
Read full article - Testosterone
“UK clinical guidelines establishing evidence-based protocols for testosterone replacement therapy in male hypogonadism, including diagnosis, treatment and monitoring.”
Jayasena CN et al., Clinical Endocrinology, 2022
Read full article - Lifestyle
“Artificial neural networks can predict sperm concentration from lifestyle questionnaire data with 86% accuracy, demonstrating that semen parameters can be meaningfully estimated without a clinical test.”
Girela JL, Gil D, Johnsson M, Gómez-Torres MJ & De Juan J, Biology of Reproduction, 2013
Read full article - Lifestyle
“Machine learning applied to 10 modifiable lifestyle factors across 5,109 men can predict sperm concentration, motility and DNA fragmentation, with smoking as the most significant predictor.”
Ma Y, Xie Z, He X et al., Frontiers in Medicine, 2022
Read full article - AI
“Ensemble machine learning models can predict specific semen diagnostic categories (normozoospermia, oligozoospermia, teratozoospermia, asthenozoospermia) from lifestyle questionnaire data alone.”
Aykaç E, Kaya C, Çelik M et al., Reproductive Biology and Endocrinology, 2024
Read full article - AI
“Artificial intelligence is being applied across semen analysis (from sperm morphology classification and motility assessment to quality prediction) with rapid growth in clinical decision support applications.”
Riegler MA et al., Medicina, 2024
Read full article - AI
“Combining epigenetic biomarkers with machine learning could transform clinical assessment of male fertility, enabling prediction models that integrate both biological and lifestyle data.”
Various authors, Frontiers in Reproductive Health, 2025
Read full article - Alcohol
“Habitual alcohol consumption is associated with reduced semen volume, sperm count, and percentage of normal morphology in a dose-dependent manner.”
Jensen TK et al., BMJ Open, 2014
Read full article - Stress
“Psychological stress is significantly associated with decreased sperm concentration and motility, and increased proportion of abnormal morphology.”
Nargund VH, Nature Reviews Urology, 2015
Read full article - Heat exposure
“Scrotal hyperthermia from laptops, saunas, tight clothing and prolonged sitting is a significant modifiable risk factor for male infertility.”
Durairajanayagam D, Agarwal A & Ong C, Reproductive BioMedicine Online, 2015
Read full article - Sleep
“Both short and long sleep duration are associated with lower total sperm count and reduced sperm survival rates.”
Chen Q et al., Sleep, 2016
Read full article - Exercise
“Moderate physical activity is positively associated with semen quality, while sedentary behaviour and extreme exercise show negative effects.”
Gaskins AJ et al., British Journal of Sports Medicine, 2013
Read full article - Diet
“A healthy dietary pattern rich in fruits, vegetables, fish and whole grains is associated with better semen quality parameters.”
Salas-Huetos A, Bulló M & Salas-Salvadó J, Human Reproduction Update, 2017
Read full article - Phone exposure
“Mobile phone exposure is associated with reduced sperm motility and viability, with effects linked to duration and proximity of use.”
Adams JA et al., Environment International, 2014
Read full article - Sperm cycle
“The full cycle of spermatogenesis takes approximately 64–74 days, meaning lifestyle changes today affect sperm quality roughly 10 weeks later.”
Amann RP, Journal of Andrology, 2008
Read full article - Sperm count
“Meta-analysis of 223 studies showing sperm counts in men declined over 50% between 1973 and 2018, with the rate of decline accelerating.”
Levine H et al., Human Reproduction Update, 2023
Read full article - Male infertility
“Male factor is a primary or contributing cause in approximately 50% of couples experiencing infertility.”
Agarwal A et al., The Lancet, 2021
Read full article - Semen quality
“Mortality decreased as sperm concentration increased up to 40 million/ml, across a wide range of diseases, suggesting semen quality is a fundamental biomarker of overall male health.”
Jensen TK et al., American Journal of Epidemiology, 2009
Read full article - Life expectancy
“Men with two or more abnormal semen parameters had a 2.3-fold higher risk of death compared with men with normal semen.”
Eisenberg ML et al., Human Reproduction, 2014
Read full article - Oxidative stress
“Oxidative stress is implicated in 30–80% of male infertility cases, damaging sperm DNA, lipid membranes and proteins through reactive oxygen species.”
Tremellen K, Human Reproduction Update, 2008
Read full article - Lifestyle
“Heat, alcohol, diet, sleep, obesity, smoking and environmental chemicals are all modifiable lifestyle factors with documented effects on semen parameters.”
Durairajanayagam D, Arab Journal of Urology, 2018
Read full article - Epigenetics
“Paternal lifestyle and environmental exposures (diet, obesity, smoking, endocrine-disrupting chemicals, stress) alter sperm epigenetic marks, influencing fertilising ability, embryo development and offspring health.”
Akhatova A, Jones C, Coward K & Yeste M, Clinical Epigenetics, 2025
Read full article - Egg activation
“PLCzeta is the sperm-specific protein responsible for activating the egg at fertilisation. Defects in PLCzeta cause a form of male infertility undetectable by routine clinical tests.”
Coward K et al., Reproduction, 2022
Read full article - ICSI failure
“When sperm fails to activate the egg properly, it can result in total fertilisation failure and recurrent ICSI failure, conditions that require targeted molecular diagnosis.”
Meng-Yao L et al. (incl. Coward K), Human Reproduction Open, 2022
Read full article - Supplements
“Lactolycopene supplementation for 12 weeks improved the proportion of fast progressive sperm by approximately 40% and improved sperm morphology in healthy males.”
Williams EA, Parker M, Robinson A, Pither S & Pacey AA, European Journal of Nutrition, 2020
Read full article - Poor semen
“Specific modifiable lifestyle and occupational factors are significantly associated with poor semen quality in a large multi-centre UK population.”
Pacey AA et al., Human Reproduction, 2012
Read full article - Environment
“Occupational exposure to glycol ethers, commonly found in paints, is associated with low motile sperm count and abnormal sperm morphology.”
Cherry N & Pacey AA et al., Systems Biology in Reproductive Medicine, 2014
Read full article - Diet
“Both low-energy diet and brief dietary intervention improve sperm motility in men with obesity, demonstrating that lifestyle changes directly improve sperm parameters.”
Jayasena CN et al., Journal of Clinical Endocrinology & Metabolism, 2024
Read full article - Testosterone
“Health optimisation remains the gold-standard management strategy for functional male hypogonadism, where low testosterone is driven by obesity, type 2 diabetes and ageing rather than irreversible HPT pathology.”
Jayasena CN et al., The Lancet Diabetes & Endocrinology, 2024
Read full article - Testosterone
“UK clinical guidelines establishing evidence-based protocols for testosterone replacement therapy in male hypogonadism, including diagnosis, treatment and monitoring.”
Jayasena CN et al., Clinical Endocrinology, 2022
Read full article - Lifestyle
“Artificial neural networks can predict sperm concentration from lifestyle questionnaire data with 86% accuracy, demonstrating that semen parameters can be meaningfully estimated without a clinical test.”
Girela JL, Gil D, Johnsson M, Gómez-Torres MJ & De Juan J, Biology of Reproduction, 2013
Read full article - Lifestyle
“Machine learning applied to 10 modifiable lifestyle factors across 5,109 men can predict sperm concentration, motility and DNA fragmentation, with smoking as the most significant predictor.”
Ma Y, Xie Z, He X et al., Frontiers in Medicine, 2022
Read full article - AI
“Ensemble machine learning models can predict specific semen diagnostic categories (normozoospermia, oligozoospermia, teratozoospermia, asthenozoospermia) from lifestyle questionnaire data alone.”
Aykaç E, Kaya C, Çelik M et al., Reproductive Biology and Endocrinology, 2024
Read full article - AI
“Artificial intelligence is being applied across semen analysis (from sperm morphology classification and motility assessment to quality prediction) with rapid growth in clinical decision support applications.”
Riegler MA et al., Medicina, 2024
Read full article - AI
“Combining epigenetic biomarkers with machine learning could transform clinical assessment of male fertility, enabling prediction models that integrate both biological and lifestyle data.”
Various authors, Frontiers in Reproductive Health, 2025
Read full article