Fertility is influenced by a wide range of factors, some of which you can change, and some you can’t. In Part 1 of this blog, we explored lifestyle and environmental factors that you can influence, such as diet, exercise, and sleep. In this second part, we’ll look at the factors that are outside of your control and explain what you can still do to protect or preserve your fertility.

Age

Age is the most important factor affecting fertility, especially for women.

• For women: Fertility begins to decline gradually in their early 30s, and more sharply after age 35. This happens because both the quantity and quality of eggs decrease with age. By the time a woman reaches 40, her chances of getting pregnant naturally are significantly lower, and the risk of miscarriage and other complications is higher.
• For men: While the decline is more gradual, age also affects fertility. Sperm quality (including the movement, shape, and DNA integrity of the sperm) can begin to decline as men get older. Older men are also more likely to experience reduced testosterone levels and erectile dysfunction, which can affect fertility.

Health Conditions, Medications, and Genetics

a) Health Conditions

In women, health conditions that affect fertility may include:

• Endometriosis, which can cause scarring and inflammation that affects the ovaries and fallopian tubes.
• Polycystic ovary syndrome (PCOS), a common hormonal disorder that can affect ovulation.
• Thyroid issues, both overactive and underactive thyroid can disrupt menstrual cycles.
• Premature ovarian insufficiency, which is when the ovaries stop working properly before age 40.
• Sexually transmitted infections (STIs), like chlamydia and gonorrhoea can lead to pelvic inflammatory disease, causing damage to reproductive organs.
• Other chronic conditions such as diabetes and autoimmune diseases can also impact fertility.

In men, common conditions that affect fertility include:

• Erectile dysfunction or ejaculatory disorders.
• Low testosterone levels.
• Varicoceles (enlarged veins in the scrotum) can impair sperm production.

b) Medications

For women, medications that may impact fertility include:

• Long-term use of certain painkillers.
• Chemotherapy.
• Antipsychotic medicines.
• Medications for fluid retention.

For men, medications that may impact fertility include:

• Sulfasalazine (used for conditions such as Crohn’s disease or rheumatoid arthritis).
• Chemotherapy.
• Long-term use of anabolic steroids.
• Certain herbal remedies.

If you're planning to conceive, it’s important to speak to your doctor about whether your medications could affect your fertility.

c) Genetic Factors

Sometimes, fertility challenges run in families. If close relatives experienced the below conditions, you may be affected by these conditions as well:

• Early menopause (you may be at higher risk of having a reduced ovarian reserve).
• Chromosomal abnormalities or genetic conditions that affect egg or sperm quality.
• Sperm abnormalities, low sperm count, or sperm mobility issues.

While you can’t change your genes, being aware of your family’s medical history can help you make informed decisions earlier.

What Can You Do to Protect Your Fertility?

If you’re thinking about starting a family someday and are worried about how factors like age or health conditions might affect your chances, learning about your options for preserving your fertility is the best first step you can take.

Egg freezing (for women) and sperm freezing (for men) allow you to store your eggs or sperm at a younger age, when the quality is higher. These options don’t guarantee a successful pregnancy later, but they can increase your chances if you face age-related or medical fertility challenges when you start trying for children.

If you have a medical condition or a family history of fertility issues, it’s worth speaking to a fertility specialist to explore your options early.

Conclusion

While you can’t change your age or your genes, understanding how these factors influence fertility can help you to plan ahead. When you combine this knowledge with healthy lifestyle choices (covered in Part 1 of this blog), you give yourself the best possible chance of conceiving when the time is right for you.

Remember: Everyone’s fertility journey is different. If you have questions or concerns, don’t hesitate to talk to your general practitioner or a fertility specialist.

Being informed is the first step. Take a moment to explore our fertility preservation section (at the top of your screen) and start your journey today.

Fertility is a complex process which can be affected by many factors, some of which you can control, and some which you can’t. Knowing how lifestyle and environmental factors can affect your fertility can help you make simple changes to improve your chances of getting pregnant.

In this blog, we will explore how different factors such as diet, exercise, weight, smoking, alcohol, recreational drugs, stress, sleep, and your job can affect fertility for both women and men.

Foods That Support Fertility

What we eat plays a crucial role in fertility. A diet rich in antioxidants, vitamins, and minerals supports reproductive health, while processed foods and excessive sugar can negatively impact hormone levels and sperm quality.

• For women: A Mediterranean-style diet rich in fruits, vegetables, whole grains, healthy fats (such as from nuts and olive oil), and lean protein is thought to have a positive impact on fertility. Folic acid, iron, and omega-3 fatty acids are particularly beneficial. Reducing trans fats, refined carbohydrates, and added sugars may also be beneficial to your fertility.
• For men: A diet rich in carbohydrates, fibre, vitamin B9, antioxidants, and fruits and vegetables has been shown to improve semen quality.

Exercise

Regular physical activity supports hormonal balance and overall health, but too much or too little can have negative effects.

• For women: Maintaining a fit and healthy body is important to naturally enhance your fertility, and exercise can also help you to reduce stress (which is another important factor in your fertility). Overtraining is rarely an issue, but for elite athletes, excessive exercise can disrupt menstrual cycles and ovulation.
• For men: Regular physical activity improves sperm quality, but excessive endurance training can reduce testosterone and sperm production.

Read more about exercise and fertility here.

Weight

Being underweight or overweight can interfere with fertility.

• For women: A healthy BMI (18.5–24.9) supports regular ovulation. Being underweight can stop menstruation, while being overweight can cause hormonal imbalance and disrupt the menstrual cycle. Being overweight can also decrease the quality of your eggs, and increase your chances of miscarriage.
• For men: Obesity is linked to lower testosterone levels and reduced sperm count. Maintaining a healthy weight can improve fertility outcomes.

Read more about weight and fertility here.

Sleep

Poor sleep patterns can disrupt reproductive hormones and reduce fertility.

• For women: Irregular sleep schedules can interfere with ovulation by disrupting the body’s natural hormone cycles.
• For men: Lack of sleep can lower testosterone levels and negatively impact sperm production.

Aim for 7–9 hours of quality sleep each night and maintain a consistent sleep schedule.

Smoking, Alcohol, and Recreational Drugs

Substances like tobacco, alcohol, and other recreational drugs have a significant negative impact on fertility.

• For women:
  • Smoking can affect fertility in several ways, including reduced egg quality, a higher risk of early menopause, and a higher risk of miscarriage.
  • It is not clear how alcohol consumption affects fertility, but avoiding alcohol is recommended if you are trying to get pregnant.
  • Recreational drugs may contribute to fertility problems, so it is recommended to avoid taking them if you are trying to get pregnant.
• For men:
  • Smoking can decrease sperm count, motility, and quality, while also increasing DNA damage in sperm.
  • Alcohol can affect sperm quality and reduce sperm production.
  • Drugs like marijuana and anabolic steroids can significantly impact sperm health and overall fertility.

For both women and men, fertility can be improved by quitting smoking, stopping or limiting alcohol intake to moderate levels, or avoiding recreational drugs. Read more about smoking and fertility here.

Stress

Chronic stress affects the body’s hormonal balance, which can interfere with ovulation in women and reduce sperm count and quality in men.

Managing stress through relaxation techniques, mindfulness, exercise, and therapy can help regulate hormone levels and improve fertility. If you are feeling stressed at work, there are a lot of helpful tips online to help you create a better work-life balance.

Read more about stress and fertility here.

Your Job

Conditions in certain jobs can affect fertility.

• Exposure to chemicals and radiation: Jobs in industries like healthcare, agriculture, and manufacturing may expose workers to hazardous substances that affect reproductive health. Protective measures and minimising exposure can help.
• Exposure to heat: Male fertility can be affected by increased temperatures, as the ideal temperature for sperm production is a couple of degrees below body temperature. Increased temperatures may affect male fertility in occupations such as factory workers, welders, and those that require tight and heavy uniforms (such as police or firefighters).
• Shift work and jet lag: Jobs requiring night shifts or frequent travel can disrupt hormonal balance, affecting ovulation and sperm quality. Maintaining a stable sleep-wake cycle can mitigate these effects.
• Physically demanding jobs: High physical strain may negatively impact female fertility but could boost sperm quality in men. Balancing workload and recovery is key.

Read more about work and fertility here.

What Can You Do to Improve Fertility?

While some factors that affect fertility are beyond our control, taking small, consistent steps toward a healthier lifestyle may enhance your reproductive health, and you may be able to improve your chances of getting pregnant. However, it’s important to remember that everyone’s fertility journey is unique, and what works for some people may not work for you. Always consult a healthcare professional if you need more guidance.

As part of your fertility journey, it’s also important to think about the things we can’t control, like age and health conditions, as these can impact fertility even more than lifestyle factors. You can read more about this in Part 2 of this blog (coming soon!).

Developed in collaboration with Daniella Corder | Menstrual cycle health & fitness coach (@coach_cords)

If you’ve ever felt amazing during a workout one week but sluggish and unmotivated the next, you’re not imagining things—your menstrual cycle could be playing a big role in how you feel. Hormonal fluctuations throughout the month impact your energy levels, metabolism, and even how your body responds to working out and what you eat.

Instead of pushing through workouts that don’t feel right or battling cravings without understanding why, adapting your approach to align with your cycle can be a game-changer. By working with your body rather than against it, you can improve performance, recovery, and overall wellbeing.

Developed in collaboration with Daniella Corder | Menstrual cycle health & fitness coach (@coach_cords)

If you’ve ever felt amazing during a workout one week but sluggish and unmotivated the next, you’re not imagining things—your menstrual cycle could be playing a big role in how you feel. Hormonal fluctuations throughout the month impact your energy levels, metabolism, and even how your body responds to working out and what you eat.

Instead of pushing through workouts that don’t feel right or battling cravings without understanding why, adapting your approach to align with your cycle can be a game-changer. By working with your body rather than against it, you can improve performance, recovery, and overall wellbeing.

How does the menstrual cycle affect your diet and how you feel during workouts?

Your menstrual cycle isn’t just about your period, it’s a month-long process that affects everything from your mood to your metabolism. It consists of four phases: the menstrual phase (days 1–4), the follicular phase (days 5–17), ovulation (around day 17), and the luteal phase (days 18–29).

Understanding these phases can help you adjust your workouts and diet to support your body’s natural rhythms rather than working against them.

How to adapt your workouts to your menstrual cycle

As hormonal fluctuations throughout the menstrual cycle can impact energy and performance, there are simple way to adjust your workouts to maximise your potential in each phase.

1. Menstrual phase: prioritise recovery and gentle movement
   
   Best workouts: light yoga, walking, stretching, or low-intensity strength training.
   
   During the menstrual phase, low energy levels and cramping might make intense workouts feel challenging. If you feel up to working out during your period, focus on form and technique rather than pushing for personal bests.
   
2. Follicular phase: go harder and build strength
   
   Best workouts: high-intensity interval training (HIIT), strength training, running, or cycling.
   
   During the follicular phase, rising oestrogen levels help to improve endurance and muscle recovery, so this is a great time to push yourself and set new fitness goals. Be aware that your oestrogen levels will rise slowly after your period, so it may take a few days for you to feel energised enough to tackle more intense workouts like HIIT, but this varies from person to person.
   
3. Ovulation: maximise performance
   
   Best workouts: high-intensity strength or cardio training, aiming for personal bests.
   
   Ovulation is a great time to go for personal bests in your training, whether you’re aiming to run faster or lift heavier. This is because both testosterone and oestrogen levels peak during ovulation, meaning you have greater muscle building (from your testosterone) and better muscle recovery (from your oestrogen).
   
4. Luteal phase: focus on moderate intensity and recovery
   
   Best workouts: low-to-moderate intensity strength training, Pilates, yoga, or swimming.
   
   During the luteal phase, higher progesterone levels can lead to fatigue and reduced endurance, and increased body temperature makes it harder to sustain endurance-based activities. If you’re weight training, you can adjust your reps, sets, weights, and rest period during this phase to a level that you’re comfortable with. The most important thing is to listen to your body and don’t feel guilty about slowing down - this is a great time for mobility work and active recovery.
   
   

Training fasted for women

Fasted training (working out on an empty stomach) is thought to help your body burn fat faster, as there is less sugar readily available in your body from food.

While this approach to training is popular, research has shown that fasted training may not be suitable for women as our brains are more sensitive to a low availability of energy than men’s. As a result of this, when we don’t provide enough energy to our body before a workout (e.g. if we train fasted), we are more likely to use our muscle tissue as fuel because our body will try to maintain our fat and carbohydrate stores.

For women, the recommended amount of food before working out is:

• 15 g of protein for strength-based workouts, OR
• 15 g of protein AND 30 g of carbohydrate for strength and cardio-based workouts

Of course, remember that all bodies are different, and if you struggle to eat a lot before your workouts, try a light pre-workout snack that is high in protein and carbohydrates, such as a small protein shake and a banana.

Tips for adjusting your diet in each phase of the cycle

Just like your workouts, your diet should align with your cycle to optimise energy and recovery.

1. Menstrual phase: replenish iron and hydrate
   
   During the menstrual phase, focus on iron-rich foods (e.g. spinach, lentils, red meat) to counteract blood loss. You might also benefit from eating warm, comforting, fibre-filled foods like soups and stews to support digestion, but try to avoid excess caffeine, which can worsen cramps.
   
2. Follicular phase: fuel performance and strength
   
   During the follicular phase, focus on lean proteins (e.g. fish, chicken, eggs) and complex carbs (e.g. potatoes, peas, oats) to support muscle growth and energy, and fermented foods (e.g. kimchi, sauerkraut, kombucha) to support your digestion. Try to avoid highly processed sugars during this phase (e.g. cakes, sugary drinks), as these can cause blood sugar spikes.
   
3. Ovulation: support muscle growth and recovery
   
   During ovulation, focus on anti-inflammatory foods (e.g. berries, tomatoes, salmon) to support joint health, and lean proteins (e.g. fish, chicken, eggs) to help maintain your stamina. Also consider eating more foods that are high in zinc (e.g. pumpkin seeds, ginger root, almonds) or magnesium (e.g. cashews, buckwheat, kelp) to help with hormonal regulation.
   
4. Luteal phase: balance blood sugar and reduce cravings
   
   During the luteal phase, focus on magnesium-rich foods (e.g. cashews, buckwheat, avocado) to reduce bloating and cravings. Slow-digesting carbs like sweet potatoes and oats will help to keep blood sugar stable, but avoid excess refined carbs (e.g. white bread, pastries), which can worsen mood swings. If you suffer from cramps, you may find it helps to reduce your caffeine intake (or even cut caffeine out entirely).
   
   Your BMR (basal metabolic rate) will increase during the luteal phase, meaning your body may need up to 300 more calories per day. So if you’re experiencing cravings during this part of your cycle, this is likely your body telling you that it needs more calories and nutrients.
   
   

Conclusion

Your menstrual cycle is a powerful tool, not a barrier, to feeling your best. By adapting your workouts and diet to match your body’s natural rhythms, you can improve performance, reduce fatigue, and support your overall health.

Start by making small changes, such as tracking your cycle and scheduling reminders in your calendar to help you remember to adjust your workouts and diet as you enter each phase of your menstrual cycle. For example, you could set reminders to focus intense workouts during your follicular phase or to add more magnesium-rich foods to your diet in your luteal phase. Over time, you’ll find a routine that works for you, embracing your cycle rather than fighting against it.

So, next time you feel off during a workout or find yourself craving carbs, remember: your body isn’t working against you, it’s trying to tell you what it needs. The more you listen, the better you’ll feel.