Your brain and body work in conjunction to produce the movements needed for exercise. Exercise requires select muscle contractions to provide the coordinated movements necessary for activities such as running, walking, jogging, swimming, skating and rowing. Several structures located in your forebrain, midbrain and hindbrain brain work together to create the necessary motor operations you need to perform various exercises.
Motor Neurons
Your muscles contract and move based on communication between the brain and body through motor neurons, or cells that transmit nerve impulses from your brain to your muscles. Before movement can occur, parts of your brain must work together to send motor neurons down your spinal cord with specific movement directions. When a motor neuron comes close to a muscle fiber, a small space, or synapse, forms called the neuromuscular junction. Neurons communicate with your muscles by releasing a chemical neurotransmitter, called acetylcholine, at the neuromuscular junction. This communication leads to a series of chemical reactions that cause your muscles to contract to enable you to participate in exercises.
Hindbrain
The hindbrain, or lower, back portion of your brain, includes the upper part of the spinal cord, the brain stem and a sphere-like structure called the cerebellum. The cerebellum receives information regarding the body's position in space to produce the coordinated movements necessary for performing exercises. Clusters of nerve cells, called ganglia, found deep inside the cerebellum initiate and control motor commands to sequence and time your desired movements. This area of your brain also helps you learn rote-memory tasks such as hitting a tennis bal. The hindbrain also contains the medulla oblongata, a large tip at the end of your spinal cord, which helps in the regulation of blood pressure and heart beat while you exercise, and the pons -- which carries signals from other parts of your brain to the cerebellum.
Forebrain
The forebrain, or cerebrum -- the largest area of the brain -- is divided into two hemispheres that contain four lobes each. The cerebral cortex, located in frontal lobe of your brain, allows you to consciously interpret your environment and remember the motor movements necessary to ride a bike, swim or participate in other activities. Planning for exact movements primarily occurs in the frontal lobe, which determines the set of muscles to contract and sends a message to a part of your brain called the primary motor cortex. The primary motor cortex then communicates with other brain parts to coordinate and activate your desired sequence of muscle movements. The forebrain also contains structures such as the hypothalamus, which regulates changes inside your body while you exercise.
Midbrain
The midbrain, located at the uppermost part of the brainstem, controls your motor reflexes and contributes to eye movements and other voluntary movements such as those needed for participation in sports and exercises. The midbrain collects information from other parts of your brain and passes this information to your motor neurons to help you complete smooth, controlled body movements. Based on scientific evidence obtained from experimental observations, specific areas of the brain are activated during exercise. Parts of the midbrain along with the pons, medulla oblongata and hypothalamus appear to produce some of the most activity while you exercise.
References
- National Institute of Neurological Disorders and Stroke: Brain Basics: Know Your Brain
- "ACSM's Advanced Execise Physiology"; Charles M. Tipton, Ph.D.; 2006
- Canadian Institute of Neurosciences: The Motor Cortex
- Canadian Institute of Neurosciences: The Role of the Neuromuscular Junction in Muscle Contraction
- Center for Neuroskills; Brain Functions and Map; Robert P. Lehr, Jr., Ph.D. ; 2010
- John W. Kimball; The Human Central Nervous System; John W. Kimbal, Ph.D.; March 2011
