How To: Fueling The Female Strength Athlete

This is a summary of the article ‘Nutritional aspects of women strength athletes’.  I’ve collected what I think are the key takeaways and have also included additional resources and information.

TL:DR:

  • Strength training is beneficial for both women and men
  • Women utilize more fats and less carbs than men during exercise
  • A positive energy and nitrogen balance is required for lean body mass (LBM) gains
  • Adequate fat intake required for health gains and optimal hormonal profile
  • Carbs are essential for performance – Emphasize micro-nutrient rich and unprocessed whole foods as source of carbs
  • Target Protein intake recommendation: 1.4–1.8 g/kg
  • No adverse effects of high protein intake in healthy individuals
  • Good idea to pad workouts with protein-rich meals
  • Creatine improves performance, strength and LBM.
  • Female athletes who engage predominately in resistance exercise training is to consume 39–44 kcal/kg bodyweight/day.
  • Women are at risk of energy imbalance disorders when energy intakes are less less than 30 kcal/kg bodyweight/day

Strength training benefits

Strength training has multiple benefits:

  • Increase bone mass and lean mass
  • Improves body composition
  • Improves cardiovascular fitness and strength
  • Enhances mental health

Women and strength training

As long as the exercise stimulus is the same, women experience similar physiological responses (e.g. increases in muscle strength and size) to men, with their decreased testosterone levels being the main limiting factor for LBM gains.

Strongman Deadlift

And no, lifting weights will not turn ladies into the hulk.

The common fear that women will become too bulky or large with strength training is not physiologically possible and should not dissuade women from engaging in this mode of exercise.

For example, Rebeka Koha. This lithe weightlifter is able to lift more than 1.5x of her bodyweight.

Or Tia Toomey, the world’s fittest woman for two years running.

These are athletes whose strength surpasses most men and have put in years of strength training. And yet they hardly look bulky or cartoonish.

Gender differences in exercise metabolism

Women tend to use more fat and less carbs than men during submaximal exercise (<85% of age-predicted max heart rate), and this has been attributed to the differences in sex steroids between genders. Women muscles have a larger area of type 1 fibres which results in relatively larger intramuscular muscle triglyceride (IMTG) stores compared to men.

Response to resistance training

Some studies have found that women use less glycogen during resistance exercise, and expend less energy and has a lower Excess Post-Exercise Oxygen Consumption (EPOC) in response to resistance exercise compared to men. However, training experience, body weight and different hormonal profiles may explain the difference in responses.

This gender difference in carbohydrate metabolism during resistance exercise may also be explained by the fact that women usually have a greater capacity for lipid breakdown and oxidation compared to men, such that glycogen is spared more in women than in men.

Importance of nutrition

A good diet can make or break a training program. Adequate energy and nutrient intake s required for muscular strength and endurance adaptations to take place. In addition, effective fueling strategies have shown to be effective in improving training and competition performance.[1]

Energy balance

Energy balance is the relationship between the calories you consume and the calories your body expends. It is important to emphasize the importance of energy balance and the dangers of poor nutrition. Especially since majority of female collegiate athletes report wanting to lose weight by reducing energy intake.

Energy balance = Calories in (food and drink)  – Calories out (exercise, bodily functions)

A positive (or at least non-negative) energy balance is need to ensure the athlete is adequate fueled, promote muscle growth and optimize body composition.

A negative energy balance will result in:

  • Increased protein utilization and may hamper muscle growth
  • Fatigue
  • Decrease in performance and mood
  • Poor recovery
  • Low thyroxine (T4) and triiodothyronine (T3) levels
  • Increased bone de-mineralization and risk of fractures
  • Possible reproductive dysfunction ( Amenorrhea)

How many calories is enough?

The paper recommends female athletes who engage primarily in resistance exercise training to consume 39–44 kcal/kg bodyweight/day. And to have a protein intake of be 1.4–1.8 g/kg bodyweight/day to maintain a positive nitrogen balance. For a 60kg athlete, that works out to ~2400kcal and 96g of protein a day.

For a normal office worker who hits the gym 2-3 times a week, consider aiming for 30-34kcal/kg bodyweight instead to compensate for the lower amount of daily activity.

It is important to note that low energy intakes, less than 30 kcal/kg bodyweight/day, have been associated with an increased risk of energy imbalance disorders (weight loss and menstrual disturbances).

The best time for women to increase food consumption seems to be during and after exercise to take advantage of the enhanced sensitivity of skeletal muscle to take up glucose and amino acids.

Is a high protein diet dangerous?

There is no strong evidence that high protein intake is detrimental for bone health, in fact some long-term studies have indicated it may be beneficial [2]. Neither is there strong evidence that it is bad for renal function for healthy people.

Increasing evidence shows that dietary substitution of carbohydrate with protein results in a variety of favourable health effects including enhanced weight loss, reduction in truncal adipose tissue, optimal maintenance of blood glucose, and improved lipid profile.

In general, it is recommended to consume animal protein because of its better bio availability. [3]

Fat intake

It is recommended to keep fat intake above 15% to help prevent female athlete triad and maintaining healthy mood and hormonal profile.

Female Athlete Triad

The female athlete triad is a medical condition observed in physically active females involving three components:

  1. Low energy availability with or without disordered eating,
  2. Menstrual dysfunction, and
  3. Low bone density.

Source: Female athlete triad. Committee Opinion No. 702. American College of Obstetricians and Gynecologists. Obstet Gynecol 2017;129:e160–7.

Creatine

The benefits of creatine has been well documented. Creatine supplementation have shown to improve anaerobic performance and long-term supplementation have been proven to improve strength and muscle gains in response to resistance exercise.

Benefits of creatine supplementation
Source: International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine

Is Creatine dangerous?

No. Studies have shown that both and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals, ranging from infants to the elderly. In fact there is growing evidence that that creatine supplementation may provide significant health benefits, especially for the elderly [4].

Creatine supplementation has been reported to help:

  • Lower cholesterol and triglyceride levels
  • Reduce fat accumulation in the liver
  • Reduce homocysteine levels
  • Serve as an antioxidant
  • Enhance glycemic control
  • Slow tumor growth in some types of cancers
  • Increase strength and/or muscle mass
  • Minimize bone loss
  • Improve functional capacity in patients with knee osteoarthritis and fibromyalgia
  • Positively influence cognitive function
  • Serve as an anti-depressant

How much creatine is needed?

Loading

The most effective way to increase muscle creatine stores is to ingest 5 g of creatine monohydrate (or approximately 0.3 g/kg body weight) four times daily for 5–7 days.

Maintaining

Once muscle creatine stores are fully saturated, creatine stores can generally be maintained by ingesting 3–5 g/day, although larger athletes may need to ingest as much as 5–10 g/day in order to maintain creatine stores

Source: Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition. 2017;14:18. doi:10.1186/s12970-017-0173-z.

 

Further reading:

Lyle McDonald – How to estimate maintenance calorie intake

https://bodyrecomposition.com/fat-loss/how-to-estimate-maintenance-caloric-intake.html/

References

[1] International society of sports nutrition position stand: nutrient timing.
https://www.ncbi.nlm.nih.gov/pubmed/28919842
[2] Is Too Much Protein Bad for Your Health?
https://www.healthline.com/nutrition/is-too-much-protein-bad-for-you
[3] What Are Good Sources of Protein? – Protein Quality
https://bodyrecomposition.com/nutrition/what-are-good-sources-of-protein-protein-quality.html/
[4] International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469049/

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