13

Training for Sport

chapter

Learning Objectives

• Review the factors involved in training, including volume and intensity

• Be able to differentiate between undertraining, acute overload training, overreaching, and overtraining

• Learn the causes, signs, and treatment of overtraining syndrome

• Find out what physiological changes occur during tapering that result in improved performance

(continued)

Learning Objectives (continued)

• Discover the strength, power, cardiovascular, and muscular endurance changes that occur due to detraining, inactivity, or immobilization

• Find out how to reduce training while preventing a decline in endurance and aerobic capacity

Individual Adaptations to Training

A person’s rate of adaptation and response to training is genetically limited and cannot be forced beyond his or her body’s capacity for development. Each individual responds differently to the same training stress.

Model of the Continuum of Training Stages in a Periodized Training Mesocycle

Adapted, by permission, from L.E. Armstrong and J.L. VanHeest, 2002, “The unknown mechanism of the overtraining syndrome,” Sports Medicine 32(1): 185-209.

The Structure of a Periodized Training Program

Adapted, by permission, from R.W. Frye, A.R. Morton, and D. Keast, 1991, "Overtraining in athletes: An update," Sports Medicine 12: 32-65.

Training Terminology

• Undertraining: type of training an athlete would undertake between competitive seasons or during active rest

• Acute overload: the athlete is stressing the body to the extent necessary to improve physiological function and performance

• Overreaching: brief period of heavy overload without adequate recovery

• Overtraining: point at which an athlete experiences physiological maladaptations and chronic performance decrements

Excessive Training

• Volume and/or intensity of training are increased to extreme levels

• High-intensity training can have negative effects on adaptation (e.g., depletion of muscle glycogen)

• Athletes may exhibit signs of chronic fatigue or overtraining

Influence of Frequency of Swim Training on (a) Blood Lactate Concentrations and

(b) Heart Rates During 25 Weeks of Training

From the beginning of week 5 through the end of week 10group 1 trained once per day whereas group 2 trained twice per day.

Training Models

Key Points• Optimal training involves following a model that

incorporates the principles of periodization• Excessive training is training that is done with an

unnecessarily high volume or intensity with little or no additional improvements in conditioning or performance

• Training volume can be increased through increases in both the duration and/or frequency of training bouts

• Training intensity determines the specific adaptations that occur in response to the training stimulus (training intensity increases, training volume must be reduced)

Overreaching

• Systematic attempt to intentionally overstress the body• Brief decrements in performance occur, followed by

increased physiological function and improved performance

• Critical phase of training

Overtraining

• Unexplained decline in performance and physiological function

• Can occur with each of the major forms of training (resistance, anaerobic, aerobic)

• Cannot be remedied by a few days of reduced training, rest, or dietary manipulation

Symptoms of Overtraining Syndrome

• Decline in physical performance• Sense of a loss in muscular strength, coordination, and work

capacity• Change in appetite• Body weight loss• Sleep disturbances• Irritability, restlessness, excitability, anxiousness• Loss of motivation and vigor• Lack of mental concentration• Feelings of depression• Lack of appreciation for things normally enjoyable

Possible Causes of Overtraining

• Periods of excessive training or emotional stress• Symptoms similar to clinical depression• Alterations in the nervous, endocrine, and immune

systems

Typical Pattern of the Expected Improvement in Performance With Acute

Overload and Overreaching (a) in Contrast to the Pattern Seen With Overtraining (b)

Reprinted, by permission, from M.L. O’Toole, 1998, Overreaching and overtraining in endurance athletes. In Overtraining in sport, edited by R.B. Krieder, A.C. Fry, and M.L. O’Toole (Champaign, IL: Human Kinetics), 10, 13.

Autonomic Nervous System Responses to Overtraining

Sympathetic Overtraining

• Increased resting heart rate

• Increased blood pressure

• Loss of appetite

• Decreased body mass

• Sleep disturbances

• Emotional instability

• Elevated basal metabolic rate

Parasympathetic Overtraining• Early onset of fatigue• Decreased resting heart

rate• Rapid heart rate recovery

after exercise• Decreased resting blood

pressure

Hormonal Responsesto Intensified Training

Possible Mediators of the Overtraining Syndrome Involving the Hypothalamus

and the SAM and HPA Axes

Adapted, by permission, from L.E. Armstrong and J.L. VanHeest, 2002, "The unknown mechanism of the overtraining syndrome," Sports Medicine 32: 185-209.

Possible Mediators of the Overtraining Syndrome Involving the Brain–Immune

System Interactions

Adapted, by permission, from L.E. Armstrong and J.L. VanHeest, 2002, "The unknown mechanism of the overtraining syndrome," Sports Medicine 32: 185-209.

Inverted J-Shaped Model of the Relationship Between the Amountof Exercise and Immune Function

Data from D.C. Nieman 1997.

(continued)

(continued)

Predicting Overtraining

• Increase in oxygen consumption (though impractical for coach to measure)

• Heart rate response to standard bout of work• Declines in performance

A Runner’s Heart Rate Response Before Training (UT), After Training (TR), and

During Overtraining (OT)

Treatment and Preventionof Overtraining

Treatment• Marked reduction in training intensity or complete rest• Counseling

Prevention• Follow periodization training procedures• Pay attention to carbohydrate intake

Overtraining

Key Points• Overtraining stresses the body beyond its capacity

to adapt, decreasing performance and physiological capacity

• Symptoms of overtraining can vary; many can accompany regular training, which makes prevention or diagnosis difficult

• Possible explanations for overtraining include changes in the function of the autonomic nervous system, altered endocrine responses, suppressed immune function, and altered brain neurotransmitters

(continued)

Overtraining (continued)

Key Points• Heart rate response to a fixed-pace exercise bout

appears to be the easiest and most accurate technique to diagnose overtraining in its early stages

• Overtraining syndrome is treated by a marked reduction in training intensity or complete rest for weeks or months

(continued)

Overtraining (continued)

Key Points• Prevention of overtraining syndrome can be

accomplished through use of periodization training procedures

• For endurance athletes, it is important to ensure adequate carbohydrate intake to meet energy needs

Tapering

Tapering for competition involves a reduction in training intensity and volume. This reduction allows your body to repair itself and restore its energy reserves to prepare you for your best performance.

Effects of Tapering

• Muscular strength increases• Energy reserves are restored

• No loss of VO2max occurs

• May increase economy• Performance increases (especially in swimmers)

.

Tapering for Peak Performance

Key Points• Decreasing training intensity and volume before a

competition increases strength, power, and performance capacity

• Optimal duration of the taper is 4-28 days or longer and is dependent on the sport, event, and the athlete’s needs

• Muscular strength increases significantly during tapering

• Allows time for muscles to be repaired from damage incurred during intense training and for energy stores to be restored

(continued)

Tapering for Peak Performance (continued)

Key Points• Less training is needed to maintain previous gains than

was originally needed to attain them, so tapering does not decrease conditioning

• Performance improves by an average of ~3% with proper tapering

Detraining

Partial or complete loss of training-induced adaptations in response to cessation of training or a substantial decrease in training load• Loss of muscle strength and power• Decrease in muscular endurance• Loss of speed, agility, and flexibility• Decrease in cardiorespiratory endurance

Loss of Muscular Strength

• Muscle atrophy caused by a decrease in muscle mass and water content

• Changes in the rate of muscle protein synthesis and degradation

• Decreased neurological stimulation with a disruption in normal fiber recruitment

• Inability to activate some muscle fibers

Loss of Muscular Endurance

• Decreased performance may be related to losses in cardiorespiratory endurance

• Decreased oxidative enzyme activity• Glycolytic enzymes remain unchanged with up to 4

weeks of detraining• Decreased muscle glycogen content • Increased blood lactate• Decreased bicarbonate

Percentage Decreases in VO2max, Muscle SDH Activity, and Cytochrome Oxidase

Activity With Detraining

.

Changes in Glycogen Content During Four Weeks of Detraining

Loss of Cardiorespiratory Endurance

20 days of bed rest leads to:– ↑ in submaximal heart rate– 25% ↓ in submaximal stroke volume– 25% ↓ in maximal cardiac output

– 27% ↓ in VO2max

– Changes are likely associated with a ↓ plasma volume

.

Changes in VO2max With 20 Days of Bed Rest

.

Adapted, by permission, from B. Saltin et al., 1968, "Response to submaximal and maximal exercise after bed rest and training," Circulation 38(7): 75.

Preventing Losses in Cardiorespiratory Endurance

You can prevent rapid losses in cardiorespiratory endurance with a minimum of three training sessions per week at an intensity of at least 70% VO2max.

.

DetrainingKey Points• Detraining is the partial or complete reversal of

training-induced adaptations in response to cessation of training or a substantial decrease in the training load

• Detraining causes muscle atrophy and losses in muscle strength and power

• Muscular endurance decreases after 2 weeks of inactivity

(continued)

Detraining (continued)

Key Points• Detraining losses in speed and agility are small, but

flexibility is lost quickly• Losses in cardiorespiratory endurance are much

greater than losses in muscle strength, power, and endurance over the same time period

• Detraining effects can be minimized by training three times a week at 70% VO2max

.