Spring 2025
Exercise Certainty in Uncertain Times
To understand a scientific article, you need to appreciate the distinction between correlation and causation. Correlation means that two events tend to occur together. As a co-relationship, something could explain part of the answer – larger muscles are stronger muscles – but not explain all of it. Stronger muscles also need to have the neuromuscular functionality and structural integrity that allow them to exert more force. That is, size alone correlates but does not cause stronger muscles.
Correlations can be necessary and/or sufficient. We refer to causation when a variable precedes an outcome and is both necessary and sufficient to the outcome, without which the outcome could not occur. Necessary is what water is for a plant to grow, but it is not sufficient. Sufficient is kind of like all the things it needs in the right combination for it to grow. A seed needs water to grow, yes, but that might not be sufficient for it to blossom without appropriate nutrients, sunshine, and the right climate. It also depends on its genetic viability. That is, its genetic code is what allows the seed to grow – necessary – in the context of water, fertilizer, sunshine, etc. All these variables are necessary but only in the right combination are they sufficient.
How does this pertain to exercise science?
When you read or hear that doing X causes Y, in terms of health or fitness, you need to look at the evidence that’s being presented. There are many methods by which you can gain strength, endurance, etc. and each one has been studied in a variety of ways with a variety of micro-adjustments to the research study in order to get published. In the real world, however, relationships may be weak or imperfect, so that the connection between the cause and effect is not always easy to discern. (We have addressed many of these here, here, here and here.) A list of correlates is calculated. When you square any one correlate, you can estimate its contribution to causation. A correlation of 0.7 does not mean it explains 70%; it only explains 49%. Pretty good but not sufficient.
The point is a correlation is necessary but, in order to be sufficient, must meet a high enough standard to stimulate body systems to change. Sufficiency must meet the “right” kind and intensity. Too much of one or more correlates can lead to maladaptions – or injury, in technical parlance. What those are depends on each person and their genetic capacity to adapt.
Along the path to fitness, however, there are may pitfalls.
The problem in training, as I learned from a lecture on plyometrics (jump training) is this: the last point of success is the first point of failure…..but you don’t know where that is till it’s too late.
Of that, I’m certain.
Means and Meaninglessness
Nuts are healthy. A study of almost 10,000 Australians over the age of 70 found that those who ate nuts daily, vs those who ate none or very infrequently, had a 23% lower risk of death and onset of dementia. (Age and Aging, Nov. 2024). But what does this mean for you?
First of all, your chances of dying are 100% so don’t expect a walnut miracle.
Second, how shall we interpret these data? And this is where stats comes into play.
If you start with 10,000 live Aussies, and study them over a 10 year period, for discussion’s sake, if 2,000 die, you can compare their diets to the 8,000 still alive. In other words, 80% did not die because they all ate nuts. Some nut-eaters died, too. To make sense of this kind of statistic, and this is true for many heart disease and cancer studies, you should understand that it’s relevant not to those who lived but those who died. So, if 870 nut eaters died and 1130 nut-abstainers died, you can see that nut eaters had a lower risk of dying over that 10 year period. In this case, they had a 870/1130 chance of dying, or 77% chance of dying compared to the others who died (100%). That means they had a 23% LOWER chance of dying because of nut eating.
But, alas, here’s where correlation vs. causation comes in to play.
You see, nut eating is not a stand-alone feature of the lives of those who eat them. Nuts are but a social and economic component of one’s diet. Being kind of expensive – especially the so-called healthy ones like almonds and walnuts – nuts are something people with more stable incomes can afford. They can also be representative of how one was raised and in what kind of culture or community one has lived. So it might be that nut-eaters have the means, inclination, and capability to take better care of themselves through an overall-healthier diet and lifestyle. Nut-eating correlates with both healthier lifestyles, diets, and longevity but, alone, does not cause either of those.
Likewise, healthy lifestyles and diets, alone, do not confer longevity. They correlate strongly with it but it takes those other pieces mentioned above in the discussion of resistance training: genetics, with gender and body type being elemental.
In other words, females tend to live longer than males and those of a more healthy body type – that is, with more muscle and less fat, regardless of overall body size – tend to live longer than those of a less healthy body type.
In sum, perhaps more resistance training and healthy nut snacking will help you live longer.
Carole Frazier’s LiveLoveEat Program for Women
Starting the week of APRIL 1, join Carol on a 5-week journey to your BestYou! Carol will be sharing her Simple Strategies for Vibrant Health in her LiveLoveEat workshop. Operating from the belief that fitness flows from the inside out, she allows that it’s also about thoughts and feelings, motivations, connectiveness—to self and others..
For more information, contact Carol at carolbuckleyfrazier@gmail.com or 615.423.3744
