Optimal hydration is key to top athletic performance, with sodium being a major player. So, can you get all the electrolytes you need from food? It's a common pitfall for athletes, often missing out on big performance gains!
Sodium isn't just another electrolyte; it's crucial for athletes because it heavily affects fluid balance. A lack of sodium can seriously impact muscle function, stamina, and overall performance.
Here's where it gets tricky: athletes usually eat a lot of whole foods. Even if they indulge occasionally, they might still miss the mark on sodium intake. Adding salt to meals helps, but it doesn’t fully match up with what sports research recommends for electrolytes.
Since sodium is at the core of hydration, it’s vital for both strength and endurance training. While endurance athletes get most of the attention for sweat and electrolyte needs, every athlete needs proper hydration. This means drinking water and getting electrolytes, even during strength workouts.
Let’s dive into a real-world example. Meet our athlete: an 85-kilogram guy who trains like a hybrid athlete. He hits the gym four times a week and runs three times, including a long run, an interval session, and a tempo run. That's seven training sessions every week!
First, let's give some context for the figures throughout this article. Here are some key insights from various scientific studies focusing on athletes' sweat rates and sodium content in their sweat:
- There is, on average, 800mg of sodium in one litre of sweat.²
- Ultra-endurance triathletes were found to lose 1.34 litres of sweat per hour.¹
- Men experience an average sweat rate of 1.8 litres per hour during a 10km run at approximately 14.6 km/hr in 21°C weather.³
- Athletes' sweat rates can vary significantly, ranging from 300 ml to 2,400ml per hour, depending on various factors like environment, sex, body size, and activity duration.⁴
Now, let's analyse our athlete's sodium and hydration needs:
Strength Training:
In our scenario, let's conservatively estimate the sodium loss during a one-hour strength training session at 0.24 grams of sodium (300ml of sweat x 0.8g of sodium).
Intervals:
Interval training brings variations in sweat rate depending on exercise intensity.⁵ On average, athletes can lose around 300 millilitres of sweat for every 10 minutes of interval training, totaling about 600 millilitres to 1.2 litres of sweat. With a sodium concentration of 0.8 grams per litre, this translates to sodium losses of 0.48 to 0.96 grams.
Tempo Run:
For the tempo run, where the athlete strikes a balance between interval and endurance-based training, let's assume a sweat rate ranging from 1,000 to 1,800 millilitres per hour, resulting in sodium losses of 0.8 to 1.44 grams during an hour-long session.
Long Run:
During a lengthy 2 to 3-hour run, our athlete may lose between 2,144mg to 3,216mg of sodium based on an average sweat loss rate of 1.34 litres per hour.
Additionally, we can't forget the daily electrolyte requirements outside of exercise. O'Donnell and colleagues (2011) found that the optimal sodium intake from a health perspective is approximately 4-6 grams per day.⁶ For our example athlete we'll consider these daily hydration recommendations alongside the sodium lost during training.
So, when we tally up the total sodium required from all seven of the athlete's training sessions in the week, plus his daily needs, we get the following:
Interval session: 480mg - 960mg
Tempo Run: 800mg - 1,440mg
Long Run: 2,144 mg - 3,216mg
Strength sessions (x4): 240mg x 4 = 960mg
Daily sodium requirement: 4,000mg - 6,000mg, multiplied by 7 Days = 28,000mg - 42,000mg
Total Weekly Sodium Requirement: 32,384mg - 48,576mg
Considering that sodium accounts for roughly 40% of salt, we can now calculate how much salt this athlete needs weekly and what their consumption might look like.
Total Weekly Salt Requirement: 80,960mg - 121,440mg or 81g - 121.5g
It's quite a challenge to predict precisely what our athlete would typically eat in a week. Preferences, cultural variations, allergies, and other factors make it a complex equation. So, for the sake of simplicity, let's consider a standard and common approach.
Assuming our athlete has three main meals each day, along with three snacks, and maintains his current weight, we can estimate his daily calorie requirements using PH Nutrition's calorie calculator, which puts it at approximately 3,500 calories.
To make things easier, we'll divide our total weekly salt requirement by 7 to find the daily average. We'll then explore a sample daily meal plan that our athlete might follow and compare his salt intake.
Sample Meal Plan (3,500 Calories)
Meal 1
-
- 4 eggs with salt
- Salt: 700mg
- 4 slices of toast with butter
- Salt: 980mg
- Half avocado
- Salt: 0mg
- 4 eggs with salt
- Total Salt Intake for Meal 1: 1,680mg
Meal 2
-
- 120g of white rice
- Salt: 15mg
- 200g of chicken breast
- Salt: 250mg
- 10ml olive oil
- Salt: 0mg
- Veg
- Salt: 80mg
- Portion of ketchup
- Salt: 250mg
- 120g of white rice
- Total Salt Intake for Meal 2: 595mg
Meal 3
-
- 150g of pasta
- Salt: 0mg
- 200g of beef mince
- Salt: 300mg
- Veg
- Salt: 80mg
- ¼ jar of standard Tomato sauce
- Salt: 750mg
- 150g of pasta
- Total Salt Intake for Meal 3: 1,130mg
Snack 1
-
- 500g of Greek yogurt
- Salt: 350mg
- Berries
- Minimal Salt
- Honey
- Minimal Salt
- 500g of Greek yogurt
- Total Salt Intake for Snack 1: 350mg
Snack 2
-
- 100g nuts
- Minimal Salt
- 100g nuts
- Total Salt Intake for Snack 2: 0mg
Snack 3
-
- Apple
- Minimal Salt
- 2 tablespoons of Peanut Butter
- Salt: 375mg
- Apple
- Total Salt Intake for Snack 3: 375mg
Total Salt Intake for the Day: 4,130mg
Converted to Sodium Intake for the Day: 1,652mg
The athlete’s total weekly requirement was 81g - 121.5g of salt, which, divided by 7 days, equals:
- 11,500mg - 17,500mg of salt required per day, or
- 4,600mg - 7,000mg of sodium per day.
Analysing our athlete's diet, it's clear that his sodium intake falls short. On this sample day, he consumed just 36% of the lower-end sodium requirement (4,600mg per day) and a mere 23.5% of the higher-end requirement (7,000mg per day).
This underscores the importance of a well-balanced nutrition plan that not only fuels their workouts but also ensures they maintain the optimal levels of electrolytes required for peak performance and optimal hydration.
References:
1. Pahnke, M.D., Trinity, J.D., Zachwieja, J.J., Stofan, J.R., Hiller, W.D. and Coyle, E.F., 2010. Serum sodium concentration changes are related to fluid balance and sweat sodium loss. Medicine and science in sports and exercise, 42(9), pp.1669-1674.
2. Barnes, K.A., Anderson, M.L., Stofan, J.R., Dalrymple, K.J., Reimel, A.J., Roberts, T.J., Randell, R.K., Ungaro, C.T. and Baker, L.B., 2019. Normative data for sweating rate, sweat sodium concentration, and sweat sodium loss in athletes: An update and analysis by sport. Journal of Sports Sciences, 37(20), pp.2356-2366.
3. Armstrong, L.E. and Casa, D.J., 2009. Methods to evaluate electrolytes and water turnover of athletes. Athletic Training & Sports Health Care, 1(4), pp.169-179.
4. Thomas, D.T., Erdman, K.A. and Burke, L.M., 2016. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics, 116(3), pp.501-528.
5. Machado, A.F., Evangelista, A.L., Miranda, J.M.D.Q., Teixeira, C.V.L.S., Leite, G.D.S., Rica, R.L., Figueira Junior, A., Baker, J.S. and Bocalini, D.S., 2018. Sweat rate measurements after high intensity interval training using body weight. Revista Brasileira de Medicina do Esporte, 24, pp.197-201.
6. O'Donnell, M.J., Yusuf, S., Mente, A., Gao, P., Mann, J.F., Teo, K., McQueen, M., Sleight, P., Sharma, A.M., Dans, A. and Probstfield, J., 2011. Urinary sodium and potassium excretion and risk of cardiovascular events. Jama, 306(20), pp.2229-2238.
