Effects of Exercise and Training on Fat Metabolism in Normal and Obese Man

Exercise and training responses in women are briefly reviewed. Part I of the paper considers the influence of gender on such responses. The average woman has a smaller inherent aerobic power and less muscular strength than a man, reflecting sociocultural influences, physical size, body composition, and hormonal milieu. Nevertheless, the best-trained women can out-perform sedentary men. The handicap of the average woman is offset by a lighter body mass and a tendency to metabolize fat rather than carbohydrate during exercise. A lack of anabolic hormones may limit training increases of muscle bulk in the female. A low initial fitness may enhance the scope for training tolerance, but it also limits tolerance of conditioning. Nevertheless, women seem less vulnerable than men to exercise-induced sudden death and overtraining. Part II of the review considers the influence of the menstrual cycle and pregnancy upon exercise and training responses. Physical activity programmes for young women should take account of possible pregnancy. Potential dangers to the foetus include an excessive rise of core body temperature, a decrease of maternal blood sugar, and foetal hypoxia. Nevertheless, regular moderate exercise generally has a favourable impact upon pregnancy outcomes. Key Words: sex differences, sociocultural issues, biological differences, physical activity, conditioning, menstruation, pregnancy, employment standards

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Muscle morphology heterogeneity: control, significance for performance and responses to training

BSAP Occasional Publication ◽

10.1017/s0263967x00041197 ◽

2004 ◽

Vol 32 ◽

pp. 11-25

Author(s):

J L L Rivero

Keyword(s):

Skeletal Muscle ◽

Muscle Blood Flow ◽

Adaptive Plasticity ◽

Muscle Fibres ◽

The Past ◽

Skeletal Musculature ◽

Skeletal Muscle Fibres ◽

Exercise And Training ◽

And Training ◽

Total Muscle

The skeletal musculature of the horse is highly developed and adapted to match the animal's athletic potential. More than half of a mature horse's body weight comprises skeletal muscle and the total muscle blood flow during maximal exercise represents 78% of total cardiac output. Exercise requires the co–ordinated application of many different body systems under the control of the nervous systems. Metabolites and oxygen reach skeletal muscle fibres via the respiratory, cardiovascular and haematological systems. The muscle fibres produce energy in the form of ATP that, via the contractile machinery, is converted into mechanical work. The structural arrangements of the musculoskeletal system provides the means with which to harness this energy to move the horse's limbs in a characteristic rhythmical pattern that is well established for each gait.Equine skeletal muscle is considerably heterogeneous and this diversity reflects functional specialisation and is the basis of its adaptive plasticity. Cellular and molecular diversity of equine muscle and the response of this tissue to exercise and training have been studied extensively over the past 30 years.

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