Overtraining

Overtraining is the result of giving your body more work or stress than it can handle. Overtraining occurs when a person experiences stress and physical trauma from exercise faster than their body can repair the damage.^[1] Overtraining can be described as a point where a person may have a decrease in performance and plateauing as a result from failure to consistently perform at a certain level or training load exceeds their recovery capacity.^[2] They cease making progress, and can even begin to lose strength and fitness. Overtraining is also known as chronic fatigue, burnout and overstress in athletes.^[3][4] It is suggested that there are different variations of overtraining, firstly monotonous program over training suggest that repetition of the same movement such as certain weight lifting and baseball batting can cause performance plateau due to an adaption of the central nervous system which results from a lack of stimulation.^[2] A second example of overtraining is described as chronic overwork type training where the subject may be training with too high intensity or high volume and not allowing sufficient recovery time for the body.^[2] It is important to note the difference between overtraining and over-reaching; over-reaching is when an athlete is undergoing hard training but with adequate recovery, overtraining however, is when an athlete is undergoing hard training without the adequate recovery. Up to 10% of elite endurance athletes and 10% of American college swimmers are affected by overtraining syndrome (unexplained underperformance for approximately 2 weeks even after having adequate resting time).^[5]

Addiction

Overtraining can lead to exercise addiction which can lead to negative physiological and psychological effects,^[6] an addictive craving for physical activity is shown to lead to extreme exercise whilst building up a tolerance to the exercise then needing to go further levels to achieve the same high.^[7] Like pharmacological drugs, physical exercise may be chemically addictive. Addiction can be defined as, the frequent engaging in the behavior to a greater extent or for a longer time period than intended.^[8][9] It is theorized is that this addiction is due to natural endorphins and dopamine generated and regulated by the exercise.^[10] Whether strictly due to this chemical by-product or not, some people can be said to become addicted to or fixated on psychological/physical effects of physical exercise and fitness.^[11] This may lead to overexercise, resulting in the "overtraining" syndrome.^[12]

Physiology

A number of possible mechanisms for overtraining have been proposed:

• Microtrauma to the muscles are created faster than the body can heal them.^[13]
• Amino acids are used up faster than they are supplied in the diet. This is sometimes called "protein deficiency".^[14]
• The body becomes calorie-deficient and the rate of break down of muscle tissue increases.
• Levels of cortisol (the "stress" hormone) are elevated for long periods of time.
• The body spends more time in a catabolic state than an anabolic state (perhaps as a result of elevated cortisol levels).
• Excessive strain to the nervous system during training.
• Systemic Inflammation which results in the release of cytokines activating an immune response^[15]

Other symptoms

Overtraining may be accompanied by one or more concomitant symptoms:^[16][17][18]

• Persistent muscle soreness^[19]
  

  Track athletes
• Persistent fatigue,^[20] this is different from just being tired from a hard training session, this occurs when fatigue continues even after adequate rest.^[5]
• Elevated resting heart rate, a persistently high heart rate after adequate rest such as in the morning after sleep, this can be an indicator of overtraining.^[5]
• Reduced heart rate variability
• Increased susceptibility to infections
• Increased incidence of injuries
• Irritability
• Depression
• Mental breakdown
• Burnout^[21][22]

Effects

Laboratory rats and mice have been used as animal models for studies of overtraining.^[23] Results in studies with rats show that overtraining can cause negative changes in the immune system which is suggested to arise from the physiological stress on the body.^[24] A study conducted at the University of Wisconsin in Milwaukee on overtraining and cycling also showed signs of physiological danger in the participants such as increased resting heart rate, decreased maximum heart rate and a decline in the body's ability to deliver oxygen to its muscles.^[25] Listed below are some of the common effects and cited signs of overtraining. Not all of the following effects will occur. The presence of any of these symptoms does not imply that an individual is overtrained.^{[16][17][18][26][27]}

Overtraining Symptoms

Information in the table above retrieved from ^[28]

Keeping hydrated

Performance

• Early onset of fatigue
• Decreased aerobic capacity
• Poor physical performance
• Inability to complete workouts
• Delayed recovery

It is also important to remember that the effect of overtraining is not isolated only to affecting the athlete's athletic ability but it can have implications on other areas of life such as performance in studies or the work force. An overtrained athlete who is suffering from physical and or psychological symptoms could also have trouble socialising with friends and family, studying for an exam or prepping for work.^[29]

Sporting example

Paralympic rowers London 2012

Rowing is a sport that requires three main aspects of physical fitness to be at their peak form. These being “Flexibility, strength and endurance” ^[30] the importance of these three aspects are that they enable an athlete to perform at a high level of intensity and avoid injury. Flexibility allows the athlete to gain a large range of motion and hold proper posture whilst in the rowing motion. Endurance is key as it will determine how well posture is held during the 5-6 minute 2 km course that is commonly rowed on, muscular endurance is key as it also enable the athletes to row at peak performance over the full course and remain competitive. Strength ties in well with flexibility as it is key that rowers have a strong core, legs, and upper body to maintain their posture, if proper posture is not maintained throughout a stroke or racing event it can largely increase the chance of injuries occurring. To be able to develop all three of these physical aspects large amounts of training will take place, “Elite rowers train between 10-14 times per week (approximately 20-28 hrs) ^[30] If proper rest periods are not followed with a structured routine, this will increase the chances for overtraining symptoms to set in. Rest is important when training as an elite rower as it enables for muscles to repair to a suitable level, if this is not done properly it can result in muscle damage and deterioration in an athletes ability to perform at his or her peak.

Treatment

Allowing more time for the body to recover:

• Taking a break from training to allow time for recovery.^[31]
• Reducing the volume and/or the intensity of the training.
  

  Injury
• Suitable periodization of training.^[32]
• Splitting the training program so that different sets of muscles are worked on different days.^[31]
• Increase sleep time.
• Deep-tissue or sports massage of the affected muscles.^[33]
• Self-massage or rub down of the affected muscles.^[34]
• Cryotherapy and thermotherapy.
• Temperature contrast therapy (contrast showers etc.). The different hot and cold stimuli can stimulate the immune system, influence release of stress hormones and encourage blood flow which ultimately lessens the body's pain sensitivity.^[35]
• Short sprints with long resting time once the athlete is able to continue with light training^[5]

Preventative Methods

Seeing as there are many non beneficial results of overtraining and the main treatment is taking time out to rest, so to avoid taking time off training prevention is very important for many athletes.^[2] An additional method preferred by many collegiate and professional level athletes is the incorporation of active recovery into training. The gradual varying of intensity and volume of training is an effective way to prevent overtraining.^[36] The athlete should be closely monitored by keeping records of weight, diet and heart rate and the training program should be adjusted in accordance to different physical and emotional stresses.^[2]

Along with the recording of rest, diet, weight and heart rates, there are multiple training types that can assist with ensuring that over training is not occurring.

Interval training ensures that, even though they are short, rest periods during training are taken. The “periods of high intensity and low intensity” ^[30] mixed characteristics of interval training enable athletes to ensure they are including rest and allowing the body to rest or repair in between intervals and in between each stage of a training session.

Australian rowers “require a mix of technique, power and endurance of both the aerobic and anaerobic energy systems” ^[37] follow a strict training schedule to enable them to ensure that rest is taken into count to ensure that overtraining is not present. “Train upwards of 11 months of the year” ^[37] this large volume of training is well spaced and though out to avoid over training symptoms.

Dietary

In the process of recovery, a fitness professional suggests ‘its important to ensure that a diet high in Carbohydrates, lean proteins and healthy fats such as omega 3 oils. Carbohydrates will provide the brain with fuel, the oils help relieve depression and proteins will rebuild overtrained muscles.’ ^[38] Protein is the main muscle building nutrient required to repair the small micro-tears inflicted on the muscle with every challenging workout.^[39] There are a lot more nutrient-dense fruits and vegetables that can be added to the diet, all of this healthy intake can or should be the same to someone who isn’t training. It's important for every adult to eat at least 2 serves of fruit and 5 serves of veggies each day.^[40]

Fruit and vegetables

• Ensuring that calorie intake at least matches expenditure.^[31]
• Ensuring total calories are from a suitable macronutrient ratio.^[41]
• Addressing vitamin deficiencies with nutritional supplements.^[31][41]

These are just some of the super foods athletes and trainers should be eating in their daily lives:

• Spinach is a great source of vitamin A and vitamin C, it also contains folate, iron, and magnesium. It has 47.2 kJ of energy per serving.^[40]
• Cabbage is a great source of Vitamin C and has 67.4kJ of energy per serving.^[40]
• Beans contain vitamin C and have 62.3 kJ of energy per serving.^[40]
• Broccoli is a great source of Vitamin C and has 65.8 kJ of energy per serving.^[40]
• Carrot is a great source of Vitamin A and contains 107.9 kJ of energy per serving.^[40]
• Strawberries contain a good source of Vitamin C, folate and fibers and have 148.1 kJ of energy per serving.^[40]
• Apples contain vitamin C and have 338.6 kJ of energy per serving.^[40]
• Oranges are a great source of Vitamin C and contain Thiamin and Folate. Oranges also have 229.3 kJ of energy per serving.^[40]
• Plums contain vitamin C and have 213.8 kJ of energy per serving.^[40]
• Seeds – sunflower, flax seed, and sesame.^[40]

See also

• Exercise addiction
• Physical fitness
• Personal Trainer
• Supercompensation
• Social influences on fitness behavior
• Sports psychology

References