What is RED-S and Why is it a Threat to Female Cyclists?

Relative Energy Deficiency in Sport (RED-S), previously known as the Female Athlete Triad, occurs when energy intake doesn't meet the demands of exercise, impacting various bodily functions. It's a much broader syndrome than just eating disorders, encompassing unintentional under-fueling and situations where athletes deliberately restrict calories to achieve a perceived performance advantage. RED-S in female cyclists is particularly concerning because it disproportionately affects women due to societal pressures and physiological differences.

Unlike male cyclists, women experience hormonal fluctuations throughout their menstrual cycle, impacting energy needs and metabolism. Furthermore, the cultural emphasis on leanness in cycling can lead to chronic under-fueling, especially in a sport that often celebrates weight loss. This can create a perfect storm for RED-S, affecting not only performance but also long-term health.

Identifying the Warning Signs of RED-S: Physical and Psychological Indicators

Recognizing the warning signs of relative energy deficiency in sport is crucial for early intervention. RED-S manifests through a combination of physical and psychological indicators, and understanding these signs can empower female cyclists to seek help before the condition becomes severe.

Here are some key indicators to watch out for:

• Physical:

  • Irregular or absent periods (amenorrhea): A hallmark sign of hormonal disruption due to energy deficiency.
  • Frequent injuries: Increased risk of stress fractures, muscle strains, and other injuries due to weakened bones and impaired recovery.
  • Fatigue and decreased performance: Persistent tiredness, reduced power output, and inability to maintain training intensity.
  • Weight loss or difficulty gaining weight: While some weight loss might be intentional, unintended weight loss or struggling to gain muscle mass can indicate RED-S.
  • Digestive issues: Bloating, constipation, or other gastrointestinal problems related to impaired nutrient absorption.
  • Hair loss and dry skin: Signs of nutrient deficiencies affecting overall health.

• Psychological:

  • Anxiety and depression: Mood changes and mental health issues associated with hormonal imbalances and inadequate nutrition.
  • Irritability and difficulty concentrating: Cognitive impairments due to lack of energy and essential nutrients.
  • Obsessive thoughts about food and weight: Preoccupation with calorie counting, restrictive eating, and body image concerns.
  • Fear of gaining weight: Intense fear of weight gain, even when underweight or malnourished.
  • Social withdrawal: Isolating oneself from friends and family due to preoccupation with food and exercise.

The Impact of RED-S on Performance, Bone Health, and Hormonal Function

RED-S in female cyclists has far-reaching consequences, impacting performance, bone health, and hormonal function. Addressing these areas is crucial for protecting overall health and ensuring sustainable cycling performance.

• Performance: Chronic under-fueling directly reduces energy availability, leading to diminished power output, decreased endurance, and impaired recovery. A cyclist struggling with RED-S may experience frequent "bonks," difficulty maintaining pace, and an inability to complete training sessions effectively. The body prioritizes survival over performance when energy is scarce.

• Bone Health: Estrogen, which can be suppressed by RED-S, plays a vital role in bone density. Reduced estrogen levels can lead to decreased bone mineral density and an increased risk of stress fractures and, in the long term, osteoporosis [cite: 16]. Cycling is a non-weight-bearing activity, which means there is already a lack of impact loading to stimulate bone growth. Adequate nutrition, particularly calcium and Vitamin D, is essential to offset this and protect bone health, especially given that women are at higher risk for osteoporosis.

• Hormonal Function: Energy deficiency disrupts the hypothalamic-pituitary-ovarian (HPO) axis, leading to irregular or absent periods (amenorrhea). This hormonal imbalance can have numerous health consequences, including infertility, increased risk of cardiovascular disease, and mood disorders. It can also affect metabolism, making it difficult to maintain a healthy weight in the long run. Does cycling affect your period? Yes, if you are not properly fueling and develop RED-S.

Fueling Strategies for RED-S Prevention: Prioritizing Energy Balance

Preventing RED-S requires a proactive approach to fueling, prioritizing energy balance, and addressing individual needs. The key is to match energy intake with energy expenditure, ensuring adequate fuel for training, recovery, and overall health.

Here are key fueling strategies for best cycling nutrition for women to prevent RED-S:

• Calculate Energy Needs: Determine your daily caloric needs based on your activity level, training intensity, and individual metabolism. Consider consulting a registered dietitian or sports nutritionist for personalized guidance.
• Prioritize Carbohydrates: Carbohydrates are the primary fuel source for cycling, providing energy for muscle contractions and brain function. Aim for adequate carbohydrate intake before, during, and after rides to replenish glycogen stores and fuel performance [cite: 7].
• Include Protein: Protein is essential for muscle repair, growth, and hormone production. Consume protein-rich foods throughout the day to support recovery and maintain lean muscle mass [cite: 8]. Female endurance athletes should aim for 1.2 to 1.4g protein per kg of body weight, increasing to 1.6-2.0g/kg during weight loss or intense training phases to preserve muscle [cite: 8, 11, 38].
• Don't Fear Fat: Healthy fats are crucial for hormone production, nutrient absorption, and overall health. Include sources like avocados, nuts, seeds, and olive oil in your diet.
• Fuel During Rides: Consume carbohydrates during longer rides to maintain energy levels and prevent glycogen depletion. Aim for 30-60 grams of carbohydrates per hour, adjusting based on intensity and duration. Some pro female cyclists consume up to 80-84g carbs/hour during intense stages.
• Listen to Your Body: Pay attention to your hunger and fullness cues. Don't restrict calories excessively or ignore your body's signals.
• Avoid Restrictive Diets: Steer clear of fad diets and extreme calorie restriction, which can lead to energy deficiency and RED-S. Cycling nutrition for weight loss female plan should focus on nutrient timing and adequate calorie intake.
• Address the weight gain question: Why do I gain weight when cycling? This can be multifactorial. Cortisol imbalances due to stress and under-fueling, can promote weight gain. Make sure you're prioritizing recovery.

One study showed that a pro female cyclist had a daily deficit of ~2,326 kcal during a tour, highlighting how extremely difficult fueling for high-performance is [cite: 9]. Even unintentional caloric deficits can lead to RED-S.

Micronutrient Considerations: Iron, Calcium, and Vitamin D for RED-S Prevention

In addition to macronutrients (carbohydrates, protein, and fat), micronutrients play a crucial role in RED-S prevention and overall health for female cyclists. Iron, calcium, and Vitamin D are particularly important.

• Iron: Women are at higher risk for iron deficiency due to menstruation. Iron is essential for oxygen transport, energy production, and immune function [cite: 1, 8]. Low iron levels can lead to fatigue, decreased performance, and impaired recovery. Consider increasing iron intake through iron-rich foods like red meat, beans, and leafy green vegetables, or iron supplements if needed.
• Calcium: Calcium is vital for bone health, muscle function, and nerve transmission. Inadequate calcium intake can increase the risk of stress fractures and osteoporosis. Ensure adequate calcium intake through dairy products, fortified plant-based milks, leafy green vegetables, and supplements if necessary.
• Vitamin D: Vitamin D is essential for calcium absorption, bone health, and immune function. Many people are deficient in Vitamin D, especially during winter months or in regions with limited sunlight exposure. Consider Vitamin D supplementation, especially since cycling is non-weight bearing.

Seeking Professional Help: When to Consult a Doctor or Nutritionist

If you suspect you may be experiencing RED-S or are struggling to balance energy intake and expenditure, seeking professional help is crucial. A doctor or registered dietitian/sports nutritionist can provide personalized guidance, assess your individual needs, and develop a comprehensive plan for recovery and prevention.

Here are some situations when consulting a professional is recommended:

• Irregular or absent periods: This is a significant warning sign of hormonal disruption and requires medical evaluation.
• Frequent injuries: Recurring stress fractures or other injuries may indicate underlying bone health issues related to RED-S.
• Persistent fatigue and decreased performance: If you're experiencing chronic fatigue and an inability to maintain training intensity despite adequate rest, it's essential to seek professional help.
• Disordered eating patterns: If you have concerns about your eating habits or body image, a mental health professional or registered dietitian specializing in eating disorders can provide support and guidance.

By prioritizing energy balance, addressing micronutrient deficiencies, and seeking professional help when needed, female cyclists can prevent RED-S, optimize their performance, and protect their long-term health.

In conclusion, best cycling nutrition for women revolves around understanding the unique physiological demands of the female body and fueling accordingly. RED-S is a serious threat, but with proactive measures and a focus on energy balance, bone health, and hormonal function, female cyclists can thrive. Start by calculating your individual energy needs, prioritizing carbohydrate and protein intake, and ensuring adequate micronutrient intake. If you experience any warning signs of RED-S, consult with a healthcare professional or registered dietitian. Take control of your health and unlock your full potential on the bike.