Predictors of exercise performance

The prediction of exercise performance depends on the type of performance and the metabolic energy provided from aerobic and anaerobic energy sources. Exercise intensity affects both respiratory and metabolic physiological parameters. Therefore, selected physiological measurements at maximal and submaximal exercise intensity provide accurate tools for exercise testing and training. Maximal oxygen uptake reflects the maximum aerobic capacity and is accepted as the best single measure for exercise performance. Respiratory measures at submaximal intensities determine the transition between moderate and heavy intensity domains and indentify anaerobic threshold. Lactate response to exercise intensity helps to identify intensities at lactate threshold, which is useful to predict performance. Those intensities correspond to maximal lactate steady state in constant load tests. However, wide range intensities at lactate threshold and several identified thresholds make their use in prescribing exercise challenging. Recent metabolic concepts involved identifying the cross-over point between relative fat and carbohydrate utilisation, and the intensity at maximal fat oxidation. Interrelationships combining metabolic and respiratory measurements may provide an integrative role to predict exercise performance, and understand the underlying factors regulating and limiting metabolism and performance. A recently proposed model has described relative carbohydrate utilisation as a function of blood lactate concentration. The model adds to the understanding of integrated metabolic factors that limit exercise performance, and may be a useful predictor, though further research is needed.