Energy Systems and ATP

Energy Systems

• Energy is the capacity to perform work and is derived from carbohydrates, fats, and proteins.
• Human movement requires the conversion of chemical energy into mechanical energy.
• Energy is released through the breaking of chemical bonds, making it available for bodily functions.
• ATP (adenosine triphosphate) is the molecule that provides immediate energy for bodily functions.
• ATP has three adenosine molecules called adenosine connected with three phosphate molecules.

How ATP Works

• ATP comprises adenosine and three phosphate groups.
• Energy release happens when one phosphate detaches from ATP.
• Stored energy in chemical bonds is then accessible allowing for muscle contraction and movement.
• After losing a phosphate, ATP converted to adenosine diphosphate or ADP.
• The resynthesis of ATP from ADP is made possible via substances like phosphocreatine (CP).

ATP Production

• Carbohydrates, fats, and protein contribute to ATP production
• Carbohydrates can be complex or simple and are converted to glucose, and then glycogen, to be stored in muscles and the liver.
• Extensive consumption is called carb loading.
• Fats are triglycerides stored, which are broken down to produce glycerol and free fatty acids.
• Free fatty acids then serve as the main energy when fat is converted to energy.
• Proteins are not used unless carbohydrates and fat stores have been depleted, and are broken down into amino acids.

Energy System Analysis Criteria

• Alactacid system (ATP/PC) generates 90g of ATP for 1–2 seconds, and uses phosphocreatine for up to 10–15 seconds.
• Lactic acid system uses blood glucose and glycogen from carbohydrates efficiently.
• A large amount of glucose is used to provide ATP quickly
• Aerobic system uses carbohydrates first, then fats, and lastly resorts to proteins.
• The aerobic system is the most efficient ATP production, and sustains activity for very long periods.

System Duration

• Alactacid system lasts 1–2 seconds on ATP; 10–15 seconds on PC.
• The lactic acid system operates for 30–45 seconds.
• The Aerobic system can supply energy for longer exercises between 12 hours of rest, 1 hour of hard work or 6 hours of intermittent exercise.
• Glycogen is spared at the end of a 'sprint'.

Fatigue

• Fatigue during the alactacid system is due to insufficient ATP and CP, meaning depleted fuel.
• Fatigue in the lactic acid system comes from lactic acid buildup in muscle cells and blood, at the lactate threshold.
• Fatigue from the aerobic system comes as the body exhausts its glycogen supply.

Byproducts

• Heat is the byproduct of the alactacid system.
• Lactate is byproduct of the lactic acid system.
• Water is byproduct of the aerobic system, but easily removed by sweat.

Process and Rate of Recovery

• The alactacid system works by breaking down ATP to ADP and releasing energy.PC then breaks down to resynthesize ATP.
• PC stores replenish 50% after 30 seconds and are fully replenished after 2 minutes.
• Glycolysis is the process for the lactic acid system and takes 30 mins – 1 hour, when the liver reconverts lactic acid into glycogen.
• The aerobic system takes between 2-3 days to recover, which is dependent on time used and breaking down glucose, fat, and protein thanks to oxygen.

Effort Intensity

• The Alactic acid (ATP/PC) system is used during maximal effort.
• The Lactic Acid System is used during high effort.
• The Aerobic system is used during Sub-maximal effort.

Sporting Examples

• The Alactacid system (ATP/PC) is used for a 100-meter sprint or javelin exercises.
• The Lactic Acid System is used for running a 400 m or cycling a 1 km.
• The Aerobic system is used for 1500 meter runs or triathlons.

Aerobic System

• The system is beneficial for events like marathons, 3 km runs, 1 km swims, and long-distance cycling.
• Glycogen breakdown in the presence of oxygen is called aerobic metabolism.

Types of Training that use Aerobic Metabolism

• Continuous: activity at the same intensity for >20 minutes.
• Fartlek: activity at different intensities for >20 minutes.
• Aerobic interval: alternation in work and rest (3:1 ratio).
• Circuit: multiple exercises with minimal rest.

Benefits of, and Limitations to Aerobic Training

• Continuous training is for overall health and fitness, but poses risk due to sustained and repetitive forces (shin splints).
• Fartlek training uses progressive overload, but has increased risk of injuries for beginners.
• The interval training allows for variance in sessions and manages fatigue, allowing to maintain motivation and intensity with sport that has frequent stops/starts
• Allows for variances across the training session and assists in the management of fatigue, while allowing to maintain motivation and intensity

Anaerobic Training

• High-intensity work with limited recovery to develop energy systems that function without adequate O2.
• It is short in duration, consists of brief activity, maximal effort, and short rest periods that don’t allow full recovery.
• This is meant to maximize energy supply, and tolerance to lactic acid in intense activity.

Types of Anaerobic Training

• Short anaerobic training consists of higher intensity, and shorter time at a lower intensity.
• Long anaerobic training consists of higher intensity for a sustained period in comparison to the time spent a lower intensity.

Anaerobic Methods within Training

• Anaerobic interval is training with short bursts of high-intensity activity, alternating with sessions of work and recovery.
• It is used to develop speed and power; it is can be designed to target specific energy systems.
• Plyometric training involves explosive concentric + eccentric muscle contractions. Example is box jumps which increase power and strength by overloading anaerobic system.
• Agility training builds the capacity to change direction quickly, with minimal impact of balance and speed using high intensity short rests.

Flexibility

• Range of motion (ROM) around a joint. Exercises target specific muscles or joints.
• Flexibility is very important to enhance performance and decrease injury.

Types of Flexibility Training

• Static stretching involves holding hamstring muscles while seated or resting.
• PNF stretching involves isometric stretches, done no longer than 30 seconds, followed by a contraction of the stretched muscle until stretch no longer felt. It lengthens muscles against resistance.
• Dynamic stretching involves muscles be stretched through continuous movement through the full range of motion at the targeted joint.
• Ballistic stretching involves a bounce or swing to gain an extra stretch, often used by explosive sports athletes.

Positive Outcome associated with Flexibility

• A flexible joint requires less energy and provides increased ROM and performance levels.
• Reduces stress while decreasing the risk of injury, also improves posture and neuromuscular coordination.

Muscular Strength

• The maximum strength that someone can generate using a single muscular contraction.
• One type of form is Free/fixed weights. – fixed weights include plated machines (bicep curls) – Benefits - the weights allow a wide range of exercises for several muscle groups
• Other methods such as Elastic / resistance bands and Hydraulic are used.

Adaptations to Muscular Contraction

• Hypertrophy is the size increase of muscle fibers and connective tissue.
• Isotonic and isometric, and isokinetic, allow muscles to change length or not (isometric).

Aerobic

• Continuous is imperative to maintain a consistent pace within marathon training.
• Continuous aerobic training enhances demanding health and fitness levels during endurance within the sport.
• An aerobic fartlek (speed play) helps adjust to an aerobic threshold when running through a variety of cross-country terrains to adjust to comfortable rates.

Strength Training

• Strength training through either free weights or fixed help create momentum.
• kettle bell swings to focus on the arms and the legs, to focus on both legs and their technique. Also known as leg press focuses on the quadriceps and allows muscles stressed on them throughout to relax, and perform their best.

Training

• In programs, there should be at least 12 weeks
• Use these training programs, in order to get the best results.
• The principle that the athletes should not loose their physiological state.

Aerobic Training

• Used to help train speed and duration
• Used to also help cardiac output and oxygen intake.

Resistance Training

• Used to help muscle weight and number of sets increase.
• Increases the number of reps and the weight.

Specificity

• Athletes need energy systems, and muscles for the best use of the sport.
• Replicate the pace.

Aerobic System

• Best used with slow twitch muscle fibres to utilize oxygen perfectly.

Power and Speed

• Correct time loads need between the sets.

Performance

If training and speed are stopped adaptations will start to minimize and performance will decrease in time.

Training

• Variety methods are very important in training, so as boring and ensure complete fitness does not leave.

Aerobic

• Help athletes to try difficult techniques, while doing cardio and more. This helps keep them up to speed.