Let’s start by defining Physical and Mental Fatigue. Physical fatigue is the temporary inability of a muscle to maintain optimal physical performance, and the severity is more with intense physical exercise. Causes of physical fatigue can range from over training, poor sleep, unhealthy diet, thyroid and hormone imbalances, and the list can go on, but these are the main contributors. Mental fatigue is similar in nature except it deals with the temporary reduction of cognitive performance. You just not are thinking clearly. It can be manifested in reduced alertness, reaction time, and overall effectiveness of your decisions. The causes of mental fatigue are much the same as physical fatigue both of which are apparent to sub-optimal athletic performance.
If you are dealing with fatigue on a daily basis, it is time to conduct an assessment. Are you missing or skipping workouts due to fatigue or do you have no desire to conduct your workout? Take a look at your daily routine, workout schedule, eating habits (which includes hydration), sleep cycle, etc. If you are true to yourself, you will be able to determine the cause of your fatigue unless it is a medical issue such as thyroid and lack of Vitamin D or Iron. If you can’t determine the cause, it may be time to see a doctor for a physical.
Although there are many factors that can cause physical and mental fatigue, I am only going to discuss five of the most common for endurance athletes.
Five factor that affect Physical and Mental Fatigue
Physical fatigue is the most common with many athletes that train too hard on a day to day basis. Most beginning athletes don’t realize that they are training too hard for their fitness level and will quickly lead to physical fatigue. It also may be due to performing at high intensity for even the most seasoned athletes. If you struggle to swim, bike, or run and perform at less than normal standards, but your alertness and concentration remain intact, you may be dealing with physical fatigue which is normal during end of each microcycle. If the fatigue continues for four days or more, you may be overtraining. It may be time for some rest. Overtraining, if not corrected will eventually lead to injury.
Mental fatigue is due to the stress placed on the mind. It is hard enough to train for one sport, when training for a triathlon it can be a very daunting task trying to manage three disciplines, family, and work schedules, not to mention strength training. If an athlete is training for their first Ironman, it places much more stress on the mind and body. Due to the way men and women process information, women will have more issues with mental fatigue. Men typically compartmentalize everything into little boxes, whereas women everything is intertwined and every thought and issue is connected. I have seen athletes over do their schedules and quickly get overwhelmed with it all. I have seen athlete’s completely break down do to mental fatigue, lose interest in training and nothing could get them motivated to train consistently again. If mental fatigue is affecting your ability to train, it may be time to take a mental break from training. Every athlete should take a break from training after their primary race; at least from structured training. It may be time to take a look at the burdens you are carrying mentally that keep you from being present in the moment. It is easy for me as I place everything in a box and only open the box when needed. If you are juggling multiple tasks/burdens, remember you have a choice where you place your attention in that moment. Take a deep breath and enjoy the world around you and forget those worries inside your head and focus on the moment. Another common reason athletes lose interest and struggle with the mental aspect of training, they have no clear goal or purpose for training. It doesn’t have to be much, but there must be something to allow you to get up early, stay up late and sacrifice your time. If you are a veteran of the sport, I challenge you to reconnect with your purpose.
Sleep deprivation or lack of sleep will drive an athlete to mental fatigue. Lack of sleep and mental fatigue will affect mood, motivation, judgment, situational awareness, and alertness. The lack of sleep will not affect your physical capability to perform. There is no direct link to affect cardiovascular responses to physical activity or muscle strength and endurance. However, time to physical exhaustion is shorter than the athletes perception of level of performance and endurance is distorted. Sleep deprivation can be caused by several factors such as less than 7 hours of sleep on a regular basis, an inconsistent sleep schedule regardless of amount of sleep, and traveling to different time zones will throw off your internal clock. If you are dealing with sleep deprivations there are several things you can do: ensure you get 7-9 hours of uninterrupted sleep per night; be as consistent as possible with sleep schedule; avoid evening exercise before bed; and avoid caffeine before bed. There are lots of studies on when to stop drinking caffeine before bed. My recommendation is no caffeine within 6-hours of your scheduled bed time. If caffeine is consumed within 6-hours, the athlete may not be aware of the effects on the sleep pattern. But each person is different on the way caffeine affects the body.
Dehydration or chronic dehydration plays a huge role in fatigue and overall athletic performance. Exercise performance is impaired when an individual is dehydrated by as little as 2% of body weight. Losses in excess of 5% of body weight can decrease the capacity for work by about 30% (Armstrong et al. 1985; Craig and Cummings 1966; Maughan 1991; Sawka and Pandolf 1990). It doesn’t take a lot of time to get dehydrated and start to lose performance capability. To avoid all the technical jargon and causes for loss of performance, just know that dehydration will affect your performance and chronic dehydration can be deadly leading to heat exhaustion. When an athlete is suffering from chronic dehydration, typically they are unaware of their need for fluids and don’t get thirsty when they need to. Water makes up more than 80% of the blood volume. If you remove 5 - 10% of water from your blood stream your body will begin to breakdown both physically and mentally. Think of it in terms of a car that doesn’t have the appropriate amount of oil in it, the car will break down if not rectified immediately. You need to drink roughly 8 glasses of water per day to stay hydrated and if you exercise, the volume must increase based on the amount of sweat. A surprising sign of chronic dehydration is we confuse thirst for hunger and have a desire for sugary snack when our body is actually asking for fluids instead. Dehydration will lead to mental and physical fatigue.
Eating habits can have a huge effect on athletic performance and could lead to both physical and mental fatigue. Inadequate calories and nutrients will impair even the most conditioned athletes. A proper diet and correct balance of energy and macronutrients will help the athlete have optimum performance. The bodies’ requirement for fuel varies based on an individual’s age, gender, body type and the sport. For the best advice on dietary requirements it is recommended to talk to a coach, dietitian or sports nutritionist. For optimal performance an athlete must include a diet that balances carbohydrates, proteins and fats. An athlete’s fuel primarily comes from carbohydrates and should receive most of their carbohydrates from health sources such as oatmeal, brown rice, fruits and vegetables. Protein is required to help repair muscle fibers broken down during training. Healthy protein choices include fish, chicken, lean beef, eggs and low fat dairy. I know the craze lately has been low or no fat products, but fat is required as part of a healthy diet. Fat provides energy, fat-soluble vitamins and essential fatty acids. However, remember to keep fat at a minimum. A good source of fat are lumens, almond butter and olive oil.
Each of the above factors can be intertwined and one will affect the other. As an example, if you are dehydrated and you have a healthy diet, your muscles to include your brain, may not be getting the nutrients required for optimal performance. It is recommended to hire a coach that can see the signs of fatigue and willing to discuss them with you. A certified coach will develop a training plan that will help reduce the chances of physical fatigue. A coach will help alleviate the need for an athlete to develop a plan that is made up as they go along. Communication with your coach on how you are feeling and what struggles you are having are critical for them to help you achieve your goals. Your coach may not have all the answers, but they will have the resources and knowledge to assist you in diagnosing the problem.
As an endurance athlete, active duty military, husband and father of two, I have been there and have experienced all of the above mentioned factors. It is not easy to balance training, work and family schedules. If you are married your family must come first and having your spouse to help you stay grounded definitely helps. They may not understand the training aspect, but they can see when things are not right and help you assess what is happening. Your physical and mental fatigue will affect your family and believe it or not, your spouse may be battling with similar issues.