Proteins

What are Proteins?

Proteins correspond to the detection of albumin (a protein that transports fatty acids in the blood, see article on albumin) and myoglobin (a protein present in muscle cells that enables oxygen to be stored and transported in the muscles for energy production) in urine. Normally, only a small amount of protein is excreted in th urine, but during exercise it is possible for protein levels in the urine to be elevated.

How can the levels be affected?

Protein levels in urine can be influenced by the following factors:

1. Exercise-induced increase in protein in the urine: Intense or prolonged physical activity, particularly endurance sports such as long-distance running, cycling or triathlon, can lead to an increase in protein in the urine. During intense exercise, muscles can break down and become damaged, causing proteins such as myoglobin to be released into the bloodstream. Some of these proteins may then be filtered by the kidneys and excreted in urine, resulting in a temporary increase in protein in the urine. Although this temporary increase is generally benign and goes away on its own, it can be an indicator of the intensity or duration of physical activity.

2. Dehydration: Dehydration, which can occur during prolonged or intense exercise, can concentrate urine and concentrate the presence of proteins in urine.

3. Heat stress: Exercise in hot, humid conditions can lead to heat stress and high muscle breakdown, which can contribute to an increase in protein in urine.

4. Muscle damage: Intense or repetitive muscle contractions during exercise can cause muscle damage and breakdown. They can lead to the release of large quantities of proteins, including myoglobin, into the bloodstream, which can exceed the filtering capacity of kidneys and lead to an increase in protein in urine. It is more common in activities involving eccentric muscle contractions, such as downhill running or high-intensity resistance training.

5. Intensity and duration of exercise: The intensity and duration of exercise can influence the degree of muscle damage and protein in urine. Longer or more intense training sessions are more likely to result in muscle breakdown and increased protein in the urine than shorter or less intense activities.

6. Individual factors: Individual factors such as fitness level, training history and muscle mass can also influence the increase in urine protein during exercise.

An increase in protein in urine may be transitory during or after exercise and is generally benign. It disappears on its own in the following days. It is important for athletes to stay hydrated, listen to their bodies and avoid physical overexertion in order to minimise the presence of exercise-induced protein in urine.

How can I maintain an optimal rate?

To help maintain optimal levels of protein in urine during sport and physical activity, consider the following strategies:

• Stay well hydrated: Drinking plenty of water before, during and after exercise to avoid dehydration can increase the concentration of protein in your urine.

• Gradually increase the intensity and duration of exercise: Avoid increasing the intensity or duration of exercise abruptly, especially if you're not used to high levels of physical activity. Increase your training sessions gradually to give your body time to adapt and to minimise the risk of muscle damage and protein in urine.

• Warm up and cool down: always warm up before exercising and cool down afterwards to avoid muscle tension and reduce the risk of muscle damage. Incorporate dynamic stretching and light cardio exercise into your warm-up and static stretching into your cool-down routine.

• Listen to your body: Watch out for signs of overtraining or excessive muscle soreness, such as persistent fatigue, reduced performance or muscle weakness. If you experience these symptoms, consider taking a rest day or reducing the intensity of your training sessions to prevent muscle damage.

• Nutritional balance: Adopt a balanced diet including high-quality proteins, complex carbohydrates, healthy fats, fruit and vegetables. Make sure you consume enough protein to meet muscle recovery needs, but avoid excess, as high levels of protein in the diet can lead to increased protein excretion in urine.

Low-fat protein	Complex carbohydrates	Antioxidant-rich foods	Essential fatty acids	Foods rich in minerals and vitamins
Chicken Turkey Fish Eggs Low-fat dairy products Tofu Legumes …	Wholegrain cereals Brown rice Wholewheat pasta Sweet potatoes Vegetables …	Berries Agrums Green leafy vegetables Nuts Seeds …	Salmon Mackerel Sardines Walnuts Linseed Rapeseed oil …	Fruits Vegetables Dairy products Wholegrain cereals Dried fruit …
Muscle repair and growth	Replenish depleted muscle glycogen reserves	Reduce inflammation and protect cells against oxidative damage	Promote muscle recovery	Promote muscle recovery

After training, make sure you rehydrate your body by drinking enough water. You can also opt for recovery drinks containing electrolytes to replace the electrolytes lost through sweating during exercise.

By incorporating these strategies into your training programme, you can help maintain optimal levels of protein in the urine during sport and physical activity, while promoting overall performance.