Lactate in Competitive sports and fitness
Competitive sports and fitness
In sports science, wearable technologies have allowed new approaches for tracking and assessing athletes’ performance. Blood levels of lactate are of particular importance and are used to tailor training intensity for athletes. Repeated training using lactate data can increase the endurance of athletes, enabling them to train at high intensities without accumulating lactate in muscle tissues. Such training enhances energy efficiency by increasing the contribution of the aerobic energy system at the same exercise intensities compared to in untrained athletes. The concentration of blood lactate is usually 1-2 mmol/L at rest but can rise to greater than 20 mmol/L during intense exertion. Monitoring the lactate threshold (LT) (where lactate accumulation increases sharply with progressively increasing exercise intensity) assists in achieving an optimized training routine. Blood lactate measurements are based currently on the use of intermittent invasive blood tests. These can cause discomfort (e.g., needle pricks, which are often accompanied by blood leakage) and potential infection risks . There is also a delay in getting the quantitative result which disrupts an intensive training session.Hence, there is a need for accurate non-invasive, real- time monitoring of blood lactate levels to overcome the constraints inherent in the existing methodologies.
Relevance in diabetes care
Individuals with Type 2 diabetes often exhibit hyperlactatemia in association with a reduced aerobic oxidative capacity and a restricted lactate transport into cells. Studies suggest a link between increased lactate levels and the manifestation and progression of insulin resistance; which is an early indicator of the development of Type 2 diabetes. Essentially, hyperlactatemia can be an early marker before glucose dysregulation becomes manifest. However, the molecular mechanism(s) responsible for the development of insulin resistance due to hyperlactatemia remain unclear and so it is uncertain whether elevated lactate levels are a cause or a consequence of Type 2 diabetes. It is known that as pre-diabetes develops into Type 2 a reduced cellular oxidative capacity in adipocytes (fat cells), where glucose metabolism in mitochondria shifts towards lactate production, leads to elevated fasting plasma blood lactate levels. The high blood lactate levels may also contribute to diabetes progression by hindering glucose uptake by cells, in this case exercise can be beneficial by improving lactate clearance and metabolism, thus physical exercise can temporally ameliorate hyperglycemia in Type 2 diabetes.Additionally, increased lactate levels in patients with poorly controlled Type 1 diabetes have been observed which suggests that enhanced plasma lactate concentrations are part of the complex metabolic changes that develop in these diseases.Lactate concentrations are chronically increased in diabetic patients with obesity. Enhanced lactate formation from adipocytes in obese individuals precedes the onset of diabetes, indicating again that chronic hyperlactatemia may be involved in the development of insulin resistance and the onset of diabetes.
Sepsis (and septic shock)
Lactate levels are a crucial biomarker in sepsis, indicating tissue stress and poor oxygen delivery (hypoperfusion), which is a life-threatening condition characterised by poor circulation of blood from heart and lungs to the body's organs. Hypoperfusion increases the risk of multi-organ failure and death. A high lactate level in blood (>4 mmol/L) suggests severe sepsis or septic shock. Subsequently regular monitoring of lactate levels can guide resuscitation efforts; for example rapidly clearing lactate (e.g. to <10% in 6 hours) with fluids improves survival. It is therefore critical to measure blood levels of lactate within hours of suspected sepsis and to monitor regularly at timed intervals. A non-invasive blood lactate measurement device is therefore of greatimportance in an emergency room situation where results can be obtained within minutes without the need to draw blood.
Traumatic brain injury (TBI)
Elevated lactate (≥4.1 mmol/L) after traumatic brain injury (TBI) is an acute biomarker for metabolic crisis and ischemia, often indicating increased mortality, particularly in severe cases. It is crucial to have this information when an individual with suspected TBI is in an emergency room situation and a non-invasive blood lactate measurement device is ideally suited to rapid initial measurements to aid diagnosis and the subsequent monitoring of treatment.
Acute myocardial infarction (AMI)
Elevated serum lactate levels (>2.5 mmol/L) are common in acute myocardial infarction (AMI) acting as a marker for infarct size and poor prognosis. Lactate can act as an early diagnostic marker for AMI, especially in patients with more than 2 hours of chest pain.Higher admission lactate, particularly above 4 mmol/L is linked to greater in-hospital mortality and shock, making measurements useful for monitoring resuscitation. Admission and 24-hour lactate levels predict 30-day and 180-day mortality, with higher levels indicating higher risk. Persistent, high-level hyperlactatemia for over 12 hours is associated with extremely poor prognosis. Increased lactate clearance within 24 hours is associated with a decreased risk of in-hospital mortality. A non-invasive blood lactate measurement device is therefore of great importance in an emergency room situation where blood lactate results can be obtained within minutes and levels monitored easily alongside the subject over extended periods without the requirement to draw blood regularly.