Restitusjon – hvile og ernæring

A study conducted at the University of Southern California in San Francisco in 2011 concluded that the risk of injury increased in younger athletes when competitions were conducted the day after a night with less than 6 hours of sleep. A 2014 study by The Institute for Scholastic Sports Science and Medicine, in California, found that sleep deprivation was among the strongest indicators of injury among teens. Even more than the number of training hours. There may be several reasons for this, but one thing is clear. Sleep is a basic physiological function that no one can do without. Even if you think you can, stupid things tend to happen.

WHY?

After a workout, competition some form of activity where you complete a work out you will have inflicted wear and tear on your body. Organs, muscles, connective tissue, etc. must therefore be repaired. If this does not happen, the body will eventually not be able to perform at the same level. Think of a tennis ball being thrown to the ground. It will eventually bounce lower and lower until it lies down. With good rest, it is as if the tennis ball becomes tighter and as if you are standing on a higher point at the next throw; at rest, your body digests the work you have done. Roughly speaking, sleep can be divided into NREM and REM sleep. The former is a «calm» sleep stage where the body temperature is lowered, the muscles relax in addition to the heart rate and breath being lowered. The deepest point of NREM sleep contributes to physiological processes that strengthen the immune system.

REM sleep, on the other hand, sends the parameters in a different direction. Body temperature, blood pressure, heart rate and respiration can be compared to a person awake. This stage helps to strengthen learning, memory and emotional health. Sleep anatomy begins with the hypothalamus, a small peanut deep inside the brain. This contains nerve cells, and they act as a control center for sleep and wakefulness. Inside this peanut we find what is called the suprachiasmatic nucleus which is responsible for regulating the circadian rhythm, which it does by receiving information about light from the eyes. The brainstem also contributes to this. It communicates with the hypothalamus to control the transition between awake and non-awake state. This happens through the production of a transmitter substance called GABA – gamma-amino-butyric acid.

Another contributor to this is the thalamus. It is responsible for sending information from the senses such as sight and hearing and since it is mostly quiet through large parts of sleep, it helps you not process impressions and memories; it limits the flow of nerve impulses. This happens in the INREM stage, but in the REM stage the thalamus is active and sends the cerebral cortex images, sounds and other impulses that fill your dreams. The cone gland also plays a role in this. It receives signals from the superachiasmatic nucleus about light exposure and then produces the hormone melatonin which helps you fall asleep when it gets dark.

NUTRITION

Fuel is needed In nutrition, we have three energy substrates: carbohydrate, fat and protein. It is mainly the need for carbohydrate and protein that increases with large amounts of exercise. At the same time, it is seen that other non-energy-giving nutrients, such as vitamins and minerals, will not inhibit endurance performance with insufficient intake. The athlete’s fluid and salt intake are also central to nutrition, as the athlete’s fluid balance is directly related to performance. Exercise also increases the total «energy consumption», and endurance athletes are usually recommended a higher energy intake to cover the increased consumption.

The type of energy substrate used depends on the intensity of the training. In zone 1 fat burning will dominate, while in zone 2 there will be approximately 50/50 of fat and carbohydrate as energy substrate. In zone 3 and up, carbohydrate will dominate as an energy substrate. Therefore, in order to perform best in moderate and high intensity, an adequate carbohydrate intake is important.

Carbohydrate

Carbohydrates are stored as glycogen in the body. Glycogen is the body’s priority energy substrate at moderate and high intensity, as it is the most readily available source of energy we have. Carbohydrates are also important for cognitive and motor processes, as they are the brain’s only source of energy. Adequate carbohydrate intake is therefore also important during technique training.

The capacity for carbohydrate storage is limited. Glycogen is stored in both muscle and liver. How much glycogen you have the opportunity to store depends on, for example, gender and muscle mass. Full glycogen stores will be important to maintain intensity. The less stored glycogen you have, the faster the stored will be drained and the body will be forced to either: 1. Use fat as an energy substrate instead. This will cause the intensity to decrease. Uses glucose that is dissolved in the bloodstream as energy, which will result in a drop in blood sugar and which can quickly lead to fatigue. Muscle proteins can also be broken down so that amino acids can be used as energy.

Regardless of the outcome, this will have an inhibiting effect on performance, and will result in a poorer training result. Recommended carbohydrate intake for endurance athletes varies with exercise frequency, amount and intensity. The greater the amount of exercise, the greater the carbohydrate requirement. During prolonged and intensive training sessions (> 90 minutes of intensive work), glycogen stores begin to deplete, and it is recommended to consume some carbohydrate during the session to maintain intensity.

Proteins

Proteins are building blocks for the body. A protein is made up of different amino acids, and is involved in several important processes in the body, such as antibodies, plasma proteins (proteins in the blood), enzymes, hormones and contractile proteins (muscle proteins). The body can produce most amino acids itself, but it are some amino acids the body depends on that it cannot produce itself. These are called essential amino acids. Adequate protein intake has been known to be important for athletes in power sports. However, adequate protein intake is just as important for endurance athletes. Large amounts of exercise will increase the need for protein. This is because a certain proportion of energy consumption is covered by the breakdown of amino acids. The more energy you consume in a day, the more protein is used for energy.

Well-trained people also have a greater muscle mass, and therefore have a higher content of protein stored in the body. The body must therefore replace a larger absolute amount of protein per day. Proteins are not directly related to performance, such as carbohydrate. But all the protein we have in the body is built into functional tissue structures or works in important processes in the body. If we consume more protein than we supply via the diet, there are mainly three stores from which protein is mobilized: plasma proteins (constitute an important part of the blood), muscle proteins (contractile proteins, myosin and actin) and proteins in the intestines (visceral). This will lead to reduced function in the tissue from which it is mobilized. For example, if proteins are mobilized from the muscle protein, this will be at the expense of the muscles’ ability to contract.

Micronutrients

Endurance athletes do not have an «increased» need for various micronutrients, but an insufficient need can affect aerobic capacity, reduce the immune system and increase the incidence of injuries. Listed below are some micronutrients that endurance athletes need to be extra careful with.

Vitamin B group

The B vitamin group contains 8 different vitamins. They are water-soluble, which means that we do not have our own «store» of the vitamin in the body. They must therefore be added frequently. There are especially 2 vitamins within the B-vitamin group that are important for endurance training, these are called Vitamin B12 and Folic Acid. They play an important role in the synthesis of hemoglobin, and the production of red blood cells. Athletes with poor B12 status may have reduced production of red blood cells, and will therefore not be able to transport enough oxygen around the body. This could affect aerobic capacity.

• Good sources of B12: Dairy products and
animal sources.
• Good sources of folic acid: Vegetables, fruits and
cereals

Vitamin D and calcium

Both vitamin D and calcium are important for building a strong skeleton, which will counteract fatigue fractures and reduce the chance of fractures in trauma. Calcium is an important component of the skeleton, while vitamin D stimulates the intestines and kidneys to absorb more calcium, so that less calcium is lost through urine, feces and sweat. Vitamin D also plays an important role in the immune system, and helps to keep the athlete healthy, as repeated periods with, for example, upper respiratory diseases will impair performance.

• Good sources of calcium: dairy products.

• Good sources of Vitamin D: oily fish, cod liver oil, extra light milk and sunlight.

Iron

Iron is an oxygen carrier, and helps to bind oxygen to the hemoglobin on the red blood cells, and is therefore important to get an adequate transport of oxygen around the body. Endurance athletes are generally prone to iron deficiency. Large amounts of exercise will increase the need for iron due to the formation of new blood vessels and increased amount of red blood cells and hemoglobin in the body. Deficiency or reduced intake of iron may result in poorer work capacity, as the transport of oxygen will be reduced, and the working muscles will have a poorer ability to utilize the oxygen.

• Good sources of iron: Coarse grain products, red meat

Fluid balance

Athletes who have periods of prolonged and intense amounts of exercise, and then preferably in hot climates, should pay extra attention to the intake of water and salt. An optimal fluid balance will be needed to maintain the intensity, and avoid dehydration. An easy way to calculate how much fluid you lose during a session is to measure body weight, just before and right after a session. Performance is reduced primarily when more than 2-3% of body weight is lost. In practice, this will correspond to approx. 1-1.5 l in a normal adult. It is mainly the aerobic capacity that weakens when the body loses too much fluid

WHY?

Reduced plasma volume (Blood volume) -> blood becomes stickier-> stickier blood makes it heavier for the heart to pump blood around the body-> Heart compensates by increasing heart rate-> faster tired.