Got a nice and fair mail after my blunt statement. Some points where personnel but one good point and challenge was .
Can I offer any studies where they looked at the 4 mmol ideas and MLSS. First there are many many studies since G. Maders idea on 4 mmol including his own critical view I showed many times on why we do not have LT but only a nice theory we still try to defend.
But there are newer studies for younger lactate users.
Here a great one just done lately. I know we all ( including me ) often have the tendency to to so called selective reading. If the studies fits to us, it is a great study, if not we try to ignore it, otherwise we have to start thinking.
Time to exhaustion at the onset of blood lactate accumulation in runners with different athletic ability
Jordan Santos-ConcejeroI,II; Cristina GranadosII; Jon IrazustaII; Iraia Bidaurrazaga-LetonaII; Jon Zabala-LiliII; Susana GilII
IUniversity of Cape Town, UCT/MRC ESSM, South Africa
IIUniversity of the Basque Country UPV/EHU, Spain.
OBJECTIVE: To characterize the physiological responses of runners of different athletic ability at the velocity at onset of blood lactate (VOBLA) and to determine if 4 mmol·L-1 represents the same relative exercise intensity for every runner.
METHODS: Eleven trained and twelve well-trained runners completed two running tests on a treadmill: first, a maximal incremental lactate test to calculate the VOBLA (Test 1), and then another one at the corresponding VOBLA until exhaustion (Test 2). Gas exchange and heart rate (HR) were continuously measured and plotted as a percentage of time to exhaustion in Test 2 (TET2). The individual lactate threshold velocity (VLT) and lactate concentration ([La-1]LT) were calculated according to the D-max method.
RESULTS: VOBLA and VLT were higher in well-trained runners (P<0.001). [La-1]LT was <4 mmol·L-1 in the well-trained runners (P<0.001), but not in trained runners. Well-trained runners were faster at VOBLA than at VLT(P<0.001). Well-trained runners ran a shorter TET2 than the trained runners (P<0.05). Moreover, well-trained runners presented a higher respiratory rate at 50, 80 and 90% of TET2 and VO2 at 20-100% of TET2 (P<0.05). TET2 was inversely correlated (P<0.01) with VOBLA and positively with personal best 10-km performance (P<0.01). VOBLA was positively correlated with the %VO2max in Test 2 (P<0.01). The standard value (4 mmol·L-1) for the concentration of blood lactate appears to represent a different exercise intensity for runners of different athletic ability.
VOBLA may not be accurated for programming running training sessions or for performing an evaluation of aerobic capacity.
Keywords: Athletes, OBLA, fatigue, exercise intensity, performance.
The determination of blood lactate concentration ([La-]) during exercise has been traditionally used as an important factor for the estimation of workload intensity in training exercise1. The maximal exercise intensity which elicits a constant [La-] over time, more specifically a rise lower than 1 mmol·L-1 in the last 20 minutes of a constant work rate test of 30 minutes, has been defined as the maximal lactate steady-state (MLSS)2. MLSS represents the highest intensity of exercise at which a balance exists between the rate of lactate production and lactate clearance3,4.
The MLSS has been proposed as a useful tool for the evaluation of aerobic capacity, training intensity prescription and the prediction of exercise performance1. However, the technique required for the accurate determination of the MLSS is complex and time-consuming, as 3 to 5 constant work-rate tests have to be performed on different days5. As a result, several authors have recommended the use of single day tests for the indirect determination of MLSS3,6.
During running exercise, a lactate concentration of 4 mmol·L-1 was reported to be associated with the MLSS7and consequently, different researchers have proposed the use of the 4 mmol·L-1 value as a reference value for the MLSS8,9. This value of 4 mmol·L-1, first proposed by Mader et al in 197610, was later termed as the onset of blood lactate accumulation (OBLA)11. Some studies have reported that the exercise intensity which induces an optimum qualitative stimulus should elicit a steady-state [La-] of approximately 4 mmol·L-112, and therefore OBLA exercise intensity has been adopted by coaches all over the world as a useful index of training status and fitness3).
However, several researchers are against the utilization of OBLA as an indirect marker for the MLSS13,14, because [La-] corresponding to MLSS may be reduced as a result of aerobic training15. In addition, it is acknowledged that the 4 mmol·L-1 value does not take into account inter-individual variability in the MLSS16. Thus, use of the OBLA as universal index for accurately estimating aerobic capacity, prescribing training intensity or a predicting performance, may have important limitations.
Currently, it is unclear if relative exercise intensity corresponding to OBLA is similar in athletes of different levels or training status. Thus, the main purpose of this study was to investigate the physiological responses at OBLA exercise intensity and consequently, to ascertain if the 4 mmol·L-1 value for lactate concentration represents the same relative exercise intensity in runners of different athletic ability. These results will assist us in determining if the OBLA index could be used to design and program running training sessions independently of the runner’s athletic level.