Without muscles a human body is only a structural form, they make the body a functional entity. Muscles are the tissues that fabricate force and motion in the body.
The force and motion produced by muscles help in changing and maintaining body posture and movement (standing, walking, facial expressions, etc.), joint stability, the motion of the internal organs (heart beat, eye movement, etc.) and movement of food through the digestive system.
Muscles are also important for maintaining the body temperature.
All the functions of muscles depend upon their contraction which generates motion and heat.
Muscle metabolism is primarily responsible for the energy requirements of the body.
There are three types of muscles, skeletal (joint to bones, internal organs, and blood vessels), smooth (present in walls of hollow organs) and cardiac (present in the walls of the heart).
In our day to day activities muscles play an indispensable role. Therefore, it becomes very important to preserve and improve the muscle strength in the body.
It becomes even more important for athletes or for people involved in physically exerting works.
Muscular endurance, i.e. the ability of muscles to repeatedly withstand force comes into play in these activities.
Better the muscle endurance, easier the work. It also prevents the muscle injury, physical trauma (such as spasms, sprains, etc.) and wounds.
Exercise or muscle training is the best way to develop muscle endurance.
During physical training, energy is lost, and the balance of physiological functions (cardiac cycle, blood pressure, body temperature, etc.) in the body is affected. It gives rise to the need for muscle recovery.
Muscle recovery involves replenishment of the energy reserve and normalization of the physiological function in the body.
If the muscle is not recovered, it can cause muscle loss, fatigue, appetite loss, dehydration, nutrient loss, increased susceptibility to infections, gastrointestinal abnormalities and lead to many other problems.
For muscle recovery, it is therefore very important to take appropriate food products that can help replenish the energy, set in order the physiological functions of the body and maintain muscle mass to maintain body health.
One such food product is cocoa, a source of dark chocolate, widely relished all over the world.
What is Cocoa?
Cocoa is the powder of the roasted, fermented cacao beans sans fat (cocoa butter).
Cacao beans are the seeds of the plant, Theobroma cacao of the family Malvaceae.
It is primarily used to make commercial chocolate. It is also commonly used in cosmetics, bakery or beverage.
In traditional medicines, cocoa has been used to treat burns, malaria, cough, fever, rheumatism, etc.
Cocoa is rich in calories, carbohydrates, proteins, flavonoids (procyanidins & epicatechin), minerals (calcium, magnesium, phosphorus, etc.), vitamins (A, B & C), tannins, methylxanthines (theobromine & caffeine) amino acids, fatty acids, and many other nutrients. 
These nutrients make cocoa a rich source of energy and enable it with properties such as antioxidant, anti-inflammatory, anticancer, hypocholesterolemic, antidepressant, antiseptic, etc.
These properties are known to be of medicinal value in wound healing, fatigue, obesity, cardiovascular problems, depression, cancer, neurodegenerative diseases, and many such disorders. 
Benefits of Cocoa in Muscle Recovery and Endurance
Cocoa is a product of high carbohydrate, proteins, and antioxidant content.
These constituents of cocoa have great benefits in muscle recovery, muscle damage and other aspects of endurance after an endurance training/ exercise.
1. Cocoa helps in Muscle Recovery
An endurance exercise or strenuous activity causes a great amount of energy loss through the metabolism of glycogen (glucose polysaccharide-an energy reserve) from liver and muscles.
It is, therefore, important to restore the energy reserve post-exercise. 
Cocoa is a rich source of carbohydrates, proteins, and antioxidants and thus, can aid in muscle recovery.
It is known to enhance glucose uptake and prevent glucose oxidation, which helps in energy replenishment. 
The combination of cocoa with milk is also being found to be a very effective source of muscle recovery after heavy exercise due to the added proteins from milk.
Chocolate milk has been found to aid in muscle recovery by balancing proteins in the muscles and improving the performance during the endurance exercise. 
In a study on soccer players, chocolate and milk combination was found to improve the markers of muscle recovery and resulted in a better performance of the players. 
The study on sports climbers showed the effectiveness of the chocolate drink in muscle recovery.
It resulted in a decrease in muscle soreness and sustained climbing, i.e. better performance. 
What does it Means? It means cocoa consumption can aid in the muscle recovery after endurance training /exercise. Cocoa helps in the replenishment of energy reserve and balances proteins in the muscles. It also subsequently helps in improving the endurance performance.
2. Cocoa Enhances Endurance Capacity
Endurance capacity is the extent to which the body can resist exercise or heavy physical work. Higher the endurance capacity more is the resistance to fatigue.
Increased endurance capacity is of high importance to athletes or people doing strenuous work. 
Cocoa is known to increase endurance capacity in combination with chocolate milk. 
In a clinical trial, consumption of dark chocolate was found to increase the exercise capacity in inactive individuals.
It was due to the rise in protein levels and other activated metabolic products, and an enhanced mitochondrial efficiency (resulting in better energy generation) mediated by cocoa constituents. 
Epicatechin, a cocoa polyphenol, has been found to improve the capillarity of skeletal muscles (exchange of oxygen & metabolites between blood and muscles for contraction) and their mitochondrial mass.
What does it Means? It means cocoa intake can increase the endurance capacity of an individual. It can help reduce fatigue and enhance the body’s resistance to exercise and improve the muscle activity in the body.
3. Cocoa can help Maintaining Endurance Training Adaptations
If one stops endurance training or exercise even for short periods, the adaptations (muscle gain, increased endurance capacity, etc.) in the body caused by the endurance training tend to decline.
When the exercise is resumed, it takes longer for the body to regain those adaptations, i.e. detraining effects. 
Cocoa can be a solution to this issue. It has been found to attenuate the detraining effects.
In a study on an animal model, administration of epicatechin from cocoa was found to maintain the adaptations of endurance training (increased mitochondrial capacity and muscle capillarity) even after 14 days of discontinuation of the exercise. 
What does it Means? It means cocoa intake can help in maintaining the exercise-induced adaptations in the body even when the exercise is discontinued for some time.
4. Cocoa Attenuates Oxidative Stress and injury in Muscles
Exercise promotes the production of oxidants or reactive oxygen species (ROS) due to the contraction process of the muscles.
The overproduction of these reactive oxygen species leads to oxidative stress or the imbalance of pro-oxidant-antioxidant ratio in the muscle cells.
These reactive oxygen species can damage the muscle fibers and lead to contractile dysfunction, and cause fatigue. 
Therefore, it is important to ameliorate the oxidative stress generated during exercise or strenuous activities.
Cocoa can be useful here as well. It has a high concentration of antioxidant flavonoids such as epicatechin.
It is known to reduce oxidative stress and prevent muscle damage.
In a study on athletes, cocoa consumption decreased the biomarkers of oxidative stress (LDH, MDA, thiols, etc.) caused by exhaustive exercise, and increased the antioxidant status in the muscle cells.
It resulted in improved physical fitness. 
The cocoa-based drink has been found to reduce muscle soreness caused by an exhaustive exercise. 
What does it Means? It means cocoa intake can attenuate the oxidative stress generated in the muscles due to exhaustive exercise. It can help in reducing muscle damage and ensure physical fitness of the body.
Dosage of Cocoa For Muscle or Post Workout Recovery
The specific dosage of cocoa for muscle recovery and endurance is not prescribed.
However, an amount of about 10-30 g per day of cocoa is recommended.2
For muscle recovery, the best to consume cocoa is by chocolate milk. Chocolate milk can be made by a tablespoon of unsweetened cocoa powder to a cup of low-fat milk.
Honey or sugar can be added for extra carbohydrates.
Healthy nuts or fruits can also be added to this drink for increasing protein and carbohydrate contents.
The cocoa drink should be taken immediately after exercise or exhaustive work.
The most beneficial cocoa is the one with more than 60% natural cocoa solids.
Cocoa is considered safe for consumption in dietary amounts. However, the presence of compounds like caffeine and some other factors call for certain precautions.
1. Cocoa can cause allergy
2. Cocoa may Cause Anxiety
3. Cocoa can have Drug Interactions
4. Cocoa can trigger a Migraine Headache
5. Cocoa Increases the risk of Kidney Stone Formation
6. Cocoa should be avoided in Bleeding Disorders
7. Cocoa should be Avoided before Surgery
8. Cocoa can aggravate GERD or IBD symptoms
9. The high amount of cocoa is not safe for pregnant and breastfeeding women
Cocoa has a very high potential for muscle recovery and endurance.
It is capable of replenishing the body with energy which helps in immediate muscle recovery.
It also helps to improve performance and endurance capacity.
Cocoa helps in maintaining the endurance training adaptations for a longer time as well.
The antioxidant activity of cocoa is useful in the prevention of muscle damage and associated fatigue.
Cocoa is a very efficacious and affordable source for muscle recovery and can be included in regular exercise diet of athletes or regular individuals.
People involved in exhaustive and strenuous work can also consume it to maintain health and work efficiency.