Sports Nutrition

Is nutrition different for endurance and strength training?

by Cait Sheppard, RD

If you’re a serious athlete, nutrition can make or break your progress. There are always new trends circulating in the fitness world, but many have little to no merit or scientific backup. At the end of the day, the basics are what’s going to help you reach your goals. For people with CF, like the general population, it’s still recommended to eat 3 meals plus 1 or 2 snacks or 5-6 small meals daily if you’re an athlete of any type. Sports nutrition differs in the composition and timing of those meals for the type of exercise you’re doing.

Endurance Training

Endurance training is any type of cardiovascular activity done over an extended period of time. If you are a long-distance runner, swimmer, cycler, or dancer then you are an endurance athlete. Due to the nature of increasing your heart rate significantly and increasing your work of breath, endurance activities use more calories than strength training. For this reason, it’s not recommended to do them while fasting, especially if you are competing, as doing so will decrease your performance.

Contrary to popular belief, studies have shown that cutting calories to reduce weight does not increase your performance, no matter what your sport is (I’m looking at you equestrians). Depriving your body of the energy it needs will only slow you down.

For optimal performance, you want to fuel your body before your workouts as well as throughout the day. Additionally, even though muscles are not the main target in this form of exercise, they are being used, so protein is very important in rebuilding them. Below are general nutrition guidelines for endurance training:

  • About 30-60 minutes before training, consume a snack containing a carbohydrate and a fat source. The carbs give you energy and the fat ensures this energy lasts you throughout your training session.
  • Consume a meal within 2 hours post session. Make sure your meal contains carbs to replenish your energy stores and protein to aid your muscles. If it’s not a meal time for you post workout then have a snack instead.
  • Hydrate. Hydrate. Hydrate. I bet you’re tired of hearing about how much water you need, but if you’re an endurance athlete this is very important. With endurance training typically comes a lot of sweat. We lose a lot of electrolytes in sweat, especially if you have CF. You can eat all the calories in the world to fuel your workouts, but if you’re dehydrated you will still feel sluggish. Aim for 35-40 mL of water per kilogram of body weight daily, subbing water with electrolyte drinks during your actual exercise session. If you want to be specific about your rehydration, you can do pre and post-workout weigh-ins to see how much sweat you lost and drink that amount of electrolyte to replenish it. For example, if you weigh 15 oz less post-workout, that indicates you lost 15 oz of sweat and need to drink at least 15 oz.

Strength Training

While endurance training challenges your heart and lung stamina, strength training challenges your muscle stamina. The main nutrients that affect your muscle growth are protein and calories. For muscles to grow, you have to eat a little more protein than normal. A fun fact about protein is that our body excretes it through our urine once it reaches its protein absorption limit. Our bodies can only absorb 20-25g of protein within a 2 hour period. So those “fitfluencers” recommending 50 g of protein at breakfast? They are confused by how biochemistry works.

In addition to protein, you need to be eating enough calories to gain muscle. If you’re under-eating your calories, your muscles will not grow to their fullest potential, if they grow at all. Muscle also increases your metabolism, because they take more energy to maintain than fat, so your calorie needs will likely increase as you gain muscle.

  • For protein, make sure you are eating at least 1-1.5 g/kilogram (kg) of body weight daily to build muscle. You can eat more than this if you want but do not exceed 4 g/kg. To find your weight in kilograms, divide your weight in pounds by 2.2.
  • You’ll also want to make sure you eat a snack or meal with protein in it within 3 hours of your workout to get a jump start on replenishing your muscles.
  • Aim for 25-30 kcals/kg per pound of body weight daily and adjust based on your progress. If you are gaining more fat than muscle, but you are wanting the opposite, then cut your calories by 2-5 calories/kg daily while maintaining your protein amount as stated above.

For example, if you weigh 150 lbs, this equates to 68.18 kg. So, you would need 68-102 g of protein and 1,705-2,040 calories daily.

It can be hard to tell if you are gaining muscle or fat if you rely solely on a scale, since a scale only measures your total body weight. The best way to test muscle gain is by a body composition tool or finding someone who can perform a body composition assessment.

Rest Days

Whether you are endurance or strength training, for the love of everything good, take a day off. Your muscles rebuild and your energy rejuvenates when you’re resting.

In a perfect world, you’d have 1-2 days of no or light (I’m talking barely doing yoga light) exercise per week. Your progress improves by resting!