Does Nutrient Timing Really Matter ?

‘18-year-old powerlifter Joseph Pena, from Texas managed to back squat a huge 1,025 pounds! (465kg) In the same competition he managed to bench press 515 pounds (233kg) and deadlift another 605 (274kg), taking his record breaking tally to 2,145 lbs (973kg) for the tournament. Imagine if this continues to improve?!’

Nutrient Timing – Does it really matter?

What is ‘Nutrient timing’?

Nutrient timing is the planned alteration of macronutrient (carbohydrate, protein and fat) intake in order to promote health. The application of knowing when & what to eat before, during and after exercise can put you in an advantageous position for exercise performance and recovery. However, it is important to understand why. It all begins with how your body reacts to exercise and the importance of hormones.

Your body contains a number of catabolic (breaking down) and anabolic (building up) hormones that are stimulated by exercise. Catabolic hormones aid the disassembly of nutrients for energy production, whilst the anabolic hormones support muscle hypertrophy (growth), tissue repair, inflammation control (the feelings that you fear after a leg workout) and also facilitate the regulation of carbohydrate, fat and protein metabolism.

Catabolic Hormones

During your workout catabolic hormones are largely responsible for the breakdown of glycogen (converting it to glucose for fuel/energy) in the liver and muscles. These hormones are also increase heart rate, blood pressure, heart contractility, blood distribution to muscle and respiration rate to meet the physiological needs of continuous exercise.

Hormones; Epinephrine, norepinephrine, cortisol.

Anabolic Hormones

Two important hormones for the anabolic phase are insulin and testosterone. Insulin sensitivity is increased during exercise meaning there is more of a demand of glucose for muscle contractions. It also accelerates the transportation of amino acids into muscle and stimulates protein synthesis (removal or repairing of damaged protein and replacing it with replicas that are stronger and more dense) in muscles. Testosterone is also a powerful hormone which promotes protein synthesis and muscle hypertrophy. The amount of testosterone increases with exercise.

The main goals behind Nutrient Timing;

§  Decrease muscle protein breakdown

§  Increase muscle protein synthesis

§  Replenish glycogen (stored carbohydrate)

§  Switch from catabolic to anabolic hormone phase (usually via insulin)

To enforce nutrient timing, academic studies have recommended that you should eat during these three phases;

§  Energy Phase – just before and during workout

§  Anabolic Phase – up to 45 minutes, post workout

§  Growth Phase – remainder of the day

     Energy Phase

Muscle glycogen is the primary fuel (followed by fat) used by the body during exercise. Low muscle glycogen stores result in muscle fatigue and the body's inability to complete high intensity exercise.

The goals with the energy phase are to increase nutrient (primarily carbohydrate and some protein) delivery to muscles, spare glycogen and protein loss, limit immune system suppression, minimize muscle damage and prepare nutritionally for a faster recovery. Carbohydrate intake prior to resistance training can increase the body's capacity to perform more sets, repetitions and prolong a resistance training workout.

Anabolic Phase

‘Protein in an hour, strengthen thy power. Protein delayed, no gains are made’

No, William Shakespeare did not come up with this phrase.

This expression is a ritual to many gym-users and should be carved in stone at every fitness center. Once the workout is in history books, there seems to be a rush to gulp down a protein shake. This is why you see many leave the gym in a rush, holding a product marketing protein shaker filled with the latest post workout supplements.

Many studies insist that ingesting the right nutrients (carbohydrates, and protein) post exercise can increase muscle endurance and strength. The optimal window for nutrient consumption is up to 45 minutes after a workout. If no nutrient consumption has taken place for up to 4 hours post exercise, then the positive effects will not be the same. 

Immediate ingestion of carbohydrate is important the insulin sensitivity post exercise causes the muscle membranes to be more permeable to glucose. This results in faster rates of glucose storage and provides the body with enough strength to initiate the recovery process.

Growth Phase

The growth phase consists of the 18 - 20 hours post-exercise when muscle repair, growth and strength occur. The goals of this phase are to maintain insulin sensitivity in order to continue to replenish glycogen stores and to maintain the anabolic state. Consuming a protein and carbohydrate meal within 1 - 3 hours after resistance training has a positive stimulating effect on protein synthesis. Carbohydrate meals with moderate to high glycaemic indexes (brown rice, oats, whole wheat bread etc.) are more favourable to enhance post-exercise fueling.