The time when commencing exercise where there is an inadequate oxygen supply.
The difference between the oxygen required during exercise and the oxygen supplied and utilized. Occurs at the onset of all activities.
Condition existing in cells during a period of temporary oxygen shortage, as, for example, during strenuous exercise, when energy is obtained through the breakdown of glucose in the absence of oxygen, and waste products, chiefly lactic acid, accumulate in the muscles and other tissues, creating a need for oxygen to rid the body of these waste products.
A physiological condition that exists in cells during periods of temporary oxygen shortage. During periods of violent exertion the body requires extra energy, which is obtained by the breakdown of glucose in the absence of oxygen, after the available oxygen has been used up. The breakdown products are acidic and cause muscle pain. The oxygen required to get rid of the breakdown products (called the oxygen deficit) must be made available after the exertion stops.
In a resting individual the potential oxygen supply to the tissues is greater than its consumption. During heavy exercise, the energy required by the tissues is greater than can be supplied by aerobic cellular metabolism and the additional energy is supplied by a biochemical reaction called anaerobic metabolism. There is a build-up of lactate a product of lactic acid from anaerobic metabolism which is ultimately oxidized after conversion to citrate and metabolism via the citric acid cycle. The increased amount of oxygen above resting concentrations which needs to be consumed to perform this metabolism is known as the oxygen debt or deficit.
At the commencement of physical activity, there is a delay in the consumption of oxygen, which is denoted as a “lag”. This lag is determined by calculating the dissimilarity between the amount of oxygen consumed during the initial phases of exercise and the amount of oxygen consumed during an equivalent period while exercising under stable conditions.
During the inception of physical activity, a time delay transpires before the oxygen consumption rate reaches a steady-state. This lag, commonly referred to as the Oxygen Uptake Kinetics Delay, is calculated by determining the contrast between the uptake of oxygen at the initial stages of exercise and during a comparable time span under stable exercise conditions.