Decreased alveolar ventilation

Bronchial hyperresponsiveness

Stiffening of lung tissue reducing expansion

Increased airway resistance

 Intracellular calcium availability

Stretch of myocardial fibres

Circulating adrenaline levels

Sympathetic nervous system activity

Fatty acids are cleaved from adipocytes by many dominant pathways that are initially activated at the onset of exercise by increased adrenaline.

Fatty acids are cleaved from adipocytes by one dominant pathway that is initially activated at the onset of exercise by increased adrenaline.

Fatty acids are cleaved from adipocytes by one dominant pathway that is initially activated at the onset of exercise by increased acetylcholine.

Fatty acids are cleaved from adipocytes by many dominant pathways that are initially activated at the onset of exercise by increased acetylcholine.

Decreased alveolar size

Reduced alveolar surface area

Increased alveolar number

Increased lung elastic recoil

Progressive, irreversible airflow limitation

Reduced mucous production

Reversible airway obstruction

Increased alveolar surface area

Mean arterial pressure doubles

Diastolic blood pressure decreases.

Total peripheral resistance triples 

Systolic blood pressure increases 

Trained athletes will have lower heart rate during and after exercise compared to untrained person 

The heart rate of an untrained athlete will recover faster than a trained athlete following a bout of exercise.

Maximal heart rate is increased by 10% in endurance trained athletes compared to untrained person

For the same submaximal workload, heart rate will be the same in a trained athlete compared to an untrained athlete.

The athlete would have higher blood volume

The athlete would have increased sympathetic activity 

The heart rate is higher in the athlete than in untrained individual

The athlete would have increased stroke volume

Increased cardiac output during arm work

Higher mechanical efficiency of arm muscles

Greater oxygen extraction by arm muscles

Greater physiological strain and lower mechanical efficiency

Aldolase is a rate limiting enzyme that converts glucose to glucose-6-phosphate

Hexokinase is a rate limiting enzyme that converts glycogen to glucose

Phosphofructokinase is a rate limiting enzyme that is suppressed by citrate

Phosphohexose isomerase is a rate limiting enzyme that is only activated by pyruvate