An increasing numbers of emails since San Diego ask the question on the use of feed-backs we may get using tHb.
I will try to get some thoughts on this .
tHb is a trend information ( no absolute values ) on potential blood flow in the tested area and when using multiple MOXY placing on potential some trends in blood flow due to certain regulatory processes like BP protection, anti gravity positions and so on.
I do not think we can use live tHb with MOXY to make a statement on the actual amount of blood on dehydration and re-hydration of blood.
Remember that in simple terms we have blood as plasma and as cells structures where the cell structure is a combination of different cells and one of the is Hb.
So when we use the trend information of tHb we assume, that the concentration of Hb is the same when we push some blood out due to contraction or anti gravity ideas as well when we increase the blood flow in an area due to vasodilatation. Many more option but in all cases we have to hope that the concentration is about stable.
What we do not know how the NIRS behaves , when we have the same numbers of tHb in the tested area but they are in a diluted plasma volume or a lower plasma volume. To explain this easier we can use the Hct ( hematocrit.)
So I may have 1 L of plasma and 100 cells in there or I have 500 ml of plasma and 100 cells in there. The Hct will change as we test the blood. What we are not sure is how that may influence the NIRS feedback. Roger may be able to give us more ideas based on the technology.
For the moment we assume more blood more Hb so if tHb goes up we have a better or higher blood volume in the tested area.
Now there is a small problem here.
A high tHb does not always mean as well a high oxygenation of a high O2Hb level. Or the opposite. A low or dropping tHb does not always mean a dropping in O2Hb.
Think that idea through. Small hint.
Look at the rest 1 minute tin a 5/1/5 as tHb goes up and than look at the biceps contraction example we showed on the forum where tHb goes up.
In other words. To make a statement on tHB and what may happened you better as well look closely at the SmO2 trend or reaction.
So one value will support or help to make a better interpretation than when we look just SmO2 alone or tHb alone..
Now many emails asked me, whether we could back up this ideas with some accepted papers and not just making up a nice story which may fit the MOXY data collection.
. Now here a newer paper which n fact is a summary form different papers from the late 1970 - 1980 and before that.
Remember the idea of knowing the history to avoid too many repetitions in mistakes but as well in great ideas.
Now here a paper abstract and summary who support our ideas, why we can sue tHb for many feed backs we get out of the trends. This is as well a reason why we developed 5/1/5 so why we like the one min rest in between equal loads.
Here the abstract.
REGULATION OF INCREASED BLOOD FLOW
(HYPEREMIA) TO MUSCLES DURING EXERCISE: A
HIERARCHY OF COMPETING PHYSIOLOGICAL NEEDS
Michael J. Joyner and Darren P. Casey
Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and Department of Physical Therapy and
Rehabilitation Science, University of Iowa, Iowa City, Iowa
L Joyner MJ, Casey DP. Regulation of Increased Blood Flow (Hyperemia) to Muscles
During Exercise: A Hierarchy of Competing Physiological Needs. Physiol Rev 95: 549–
601, 2015; doi:10.1152/physrev.00035.2013.—This review focuses on how blood
flow to contracting skeletal muscles is regulated during exercise in humans. The idea is
that blood flow to the contracting muscles links oxygen in the atmosphere with the
contracting muscles where it is consumed. In this context, we take a top down approach and review the basics of oxygen consumption at rest and during exercise in humans, how these values change with training, and the systemic hemodynamic adaptations that support them. We highlight the very high muscle blood flow responses to exercise discovered in the 1980s. We also discuss the vasodilating factors in the contracting muscles responsible for these very high flows. Finally, the competition between demand for blood flow by contracting muscles and maximum systemic cardiac output is discussed as a potential challenge to blood pressure regulation during heavy large muscle mass or whole body exercise in humans. At this time, no one dominant dilator mechanism
accounts for exercise hyperemia. Additionally, complex interactions between the sympathetic nervous system and the microcirculation facilitate high levels of systemic oxygen extraction and permit just enough sympathetic control of blood flow to contracting muscles to regulate blood pressure during large muscle mass exercise in humans.
So when we look at tHb in a 5/1/5 we have some ideas in font of us:
a) is the tHb dropping due to mechanical reason like compression.?
b) is it dropping due to some physiological reflex reactions like BP control. or metaboreflex and other reason
c) is it going up due to vasodilatation
d) is it going up due to outflow restrictions like venous occlusion trends
To have a better feedback we than add SmO2 trend..
Below three examples to just try to get a grip on this ideas.
Look at red and brown. Red is O2Hb or Hb which is loaded with O2 . So when "normally" O2Hb drops we have less loaded, as HHb goes up (unloaded.) So SmO2 which really is % of O2Hb in the tHb will drop as well. So in the above example we have an increase in tHb but a drop in SmO2 or in the pic O2Hb . Why ?
Now above another idea of a workout and you can see what we tried to achieve is a drop in tHb and at the same time a drop in O2Hb or ( SmO2 ). What did we do here and why is here tHb dropping compared with the first example where tHb increase but in both O2Hb or SmO2 will drop ?
Now here a nice example where we have a drop in tHb and a drop i O2Hb ( SmO2 ) but we have as well a drop in tHb but an increase in O2Hb ( SmO2 ). We do NOT have in this picture a increase in tHb and a drop in O2Hb.
My grade 10 students have next week to create a workout, where we have all different i options on hand in one workout.
a) Increase of tHb and drop in O2Hb,
b) increase in tHb and increase in O2Hb
c) decrease in tHB and decrease in O2Hb
d) decrease in tHb and increase in O2Hb
Try to create this workout for yourself.