PHYSIOLOGICAL BASICS FOR ATHLETIC TRAINING

Olavi Pajala

C H A P T E R 12

TRAINING FOR SPORT

Did You Know…?

A person’s rate of adaptation and response to training depends on that individual. He or she cannot be forced beyond his or her body’s capacity for development. Thus, training programs must take these individual differences into account.

OPTIMIZING TRAINING—A MODEL

PERIODIZED TRAINING, MACROCYCLE

PERIODIZED TRAINING, MESOCYCLE

PERIODIZED TRAINING, MICROCYCLE

Optimal Training Load

Progressive overload—progressive increase in training load as body adapts

Training volume—duration and frequency

Training intensity—force of muscle action and stress on the muscular and cardiovascular systems

Resistance training (high intensity and low volume)

Aerobic training (high volume and lower intensity)

Rest periods—without them, muscles become chronically fatigued and depleted of stored energy

EXCESSIVE TRAINING—BLOOD LACTATE AND HR

TRAINING VOLUME vs IMPROVEMENT

Key Points

Excessive training refers to training with an unnecessarily high volume or intensity.

Excessive training does not lead to additional gains in performance and can lead to chronic fatigue and decreased performance.

Training Demands

Increase the duration or frequency of training to increase training volume.

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Key Points

Training Demands

Training intensity can determine specific adaptations to training.

High-intensity, low-volume training increases muscle strength and speed.

High-volume, low-intensity training (50% to 90% VO2max) increases aerobic capacity.

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Did You Know…?

Long daily workouts may not be the best training method for some sports. It appears that training volume could be reduced by as much as one half in some sports, without reducing the training benefits and with less risk of overtraining the athlete to the point of decreased performance.

Effects of Training Too Much

Excessive training—well above what is needed for peak performance, but does not strictly meet the criteria for overreaching or overtraining. It can lead to chronic fatigue and decrements in performance.

Overreaching—a brief period of heavy overload without adequate recovery, thus exceeding the athlete’s adaptive capacity. There is a performance decrement, but it is relatively short-term, lasting several days to several weeks

Overtraining—that point at which an athlete starts to experience physiological maladaptations and chronic performance decrements, lasting weeks, months or longer.

Overtraining

Continued training beyond the point that would be optimal; can be related to intensity, duration, frequency, or any combination of these three

Staleness is a related concept

The key is to design a training program that provides the optimal level of stress but does not overstress the athlete

Symptoms of Overtraining Syndrome

Decline in physical performance with continued training

Loss in muscular strength, coordination, and maximal working capacity

General fatigue

Change in appetite and body weight loss

Sleep disturbances

Irritable, restless, excitable, anxious

Loss of motivation

Lack of mental concentration

Feelings of depression

OVERREACHING vs OVERTRAINING

Possible Causes of Overtraining

Periods of excessive training and/or emotional stress

Abnormal responses in the autonomic nervous system—sympathetic and parasympathetic

Disturbances in endocrine function

Depressed immune function

HORMONAL RESPONSES TO OVERTRAINING

HYPOTHALAMUS, SAM, and HPA WITH OVERTRAINING

BRAIN-IMMUNE SYSTEM INTERACTIONS

EXERCISE AND IMMUNE FUNCTION

Predicting Overtraining

Increase in oxygen consumption for the same rate of work (though impractical for coach to measure)

Increased heart rate response to the same rate of work

Declines in performance

VO2 IN EARLY AND LATE SEASON.

HEART RATE RESPONSES TO TRAINING

Treatment of Overtraining

Reduce training intensity for several days

Rest completely for several days or weeks if symptoms don’t improve

Seek counseling

Prevent overtraining by alternating easy, moderate, and hard training

Eat sufficient carbohydrate to prevent glycogen depletion

Key Points

Overreaching and overtraining lead to decreased performance capacity.

Symptoms of overreaching or overtraining may occur briefly with regular training.

Overreaching and Overtraining

Overtraining may be caused by abnormal responses in the autonomic nervous and endocrine systems and suppressed immune function.

Heart rate response appears to be the most reliable warning of overtraining.

Overtraining syndrome is treated most effectively with rest and proper nutrition.

Did You Know…?

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

Effects of Properly Tapering

Muscular strength increases

Energy reserves are restored

Performance increases

No loss of VO2max occurs.

EFFECTS OF A 7-DAY TAPER IN RUNNERS

a b

TAPERING AND VO2SUBMAX.

c

Detraining

Partial or complete loss of training-induced adaptations in response to either the cessation of training or to a substantial decrement in the training load

Loss of muscle size, strength, and power

Decrease in muscular and cardiorespiratory endurance

Loss of speed, agility, and flexibility

Loss of Muscle Strength With Detraining

Muscle atrophy accounts for a loss in development of maximal muscle fiber tension.

Normal fiber recruitment is disrupted; some fibers are unable to be recruited.

Muscle requires minimal stimulation (training once every 10 to 14 days) to retain training gains.

BIOKINETIC SWIM BENCH AND STRENGTH CHANGES WITH DETRAINING

a b

Loss of Muscular Endurance With Detraining

Decreased performance may be related to losses in cardiorespiratory endurance.

Oxidative enzyme activity in muscles decreases.

Glycolytic enzymes remain unchanged with up to 84 days of detraining.

Muscle glycogen content (and thus storage capacity) decreases.

Acid-base balance becomes disturbed.

Muscle capillary supply and fiber type may change.

DETRAINING, VO2MAX, AND OXIDATIVE ENZYMES

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DETRAINING AND MUSCLE GLYCOGEN

Blood Lactate, pH, and Bicarbonate (HCO3) in Eight Collegiate Swimmers Undergoing Detraining

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Lactate (mmol/L) 4.2 6.3 6.8 9.7c

pH 7.259 7.237 7.236 7.183c

HCO3 (mmol/L) 21.1 19.5c 16.1c 16.3c

Swim time (s) 130.6 130.1 130.5 130.0

Measurement 0a 1b 2 4

Weeks of detraining

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Note. Measurements were taken immediately after a fixed-pace swim.

aThe values at week 0 represent the measurements taken at the end of 5 months of training. bThe values for weeks 1, 2, and 4 are the results obtained after 1, 2, and 4 weeks of detraining, respectively. cSignificant difference from the value at the end of training.

Loss of Cardiorespiratory Endurance

Losses are greatest in highly trained individuals.

Plasma volume decreases

Stroke volume decreases

Endurance performance decreases

VO2max decreases.

Did You Know…?

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

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CHANGES IN VO2MAX WITH BED REST.

Effects of Detraining and Blood Volume Expansion

Blood volume (ml) 5,177 4,692b 5,412

Stroke volume (ml/beat)a 166 146b 164

VO2max (L/min) 4.42 4.16b 4.28

Exercise time to exhaustion (min) 9.13 8.44 8.06c

Parameter Trained Detrained Detrained

Normal Expanded blood blood

volume volume

aStroke volume measured during submaximal exercise. bDenotes a significant difference from the trained (normal blood volume) and detrained (expanded blood volume) values. cDenotes a significant difference from the trained (normal blood volume) value.

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Retraining

Recovery of conditioning after a period of inactivity.

Affected by fitness level and the length and extent of inactivity.

If a cast allows some range of movement, retraining time can be reduced.

Electrical stimulation of muscles can prevent muscle fiber atrophy.

Key Points

Detraining is the cessation of regular physical training

Retraining is resuming training after a period of inactivity.

Detraining and Retraining

The greater the training gains achieved, the greater the losses with detraining.

Detraining results in losses of muscle size, strength, power, and endurance; speed, agility, and flexibility; and cardiorespiratory endurance.

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