Exercise and Stress

There are plenty of sources of stress in our lives. Exercise both helps with stress and causes stress. Here’s a good survey of the subject (Expert Rev Endocrinol Metab. 2006 Nov 1; 1(6): 783–792.  Stress and the neuroendocrine system: the role of exercise as a stressor and modifier of stress. Anthony C Hackney, PhD, CPH).

From the summary:

  • Physical exercise is a stressor to the human body and serves as a robust activator of the neuroendocrine system, provided that the exercise is of sufficient volume (i.e., intensity and/or duration). The magnitude of the neuroendocrine stress response to exercise seems directly proportional to the volume of exercise exposure. These stress hormone responses are typically very transient in nature and do not last longer than a few minutes to hours into recovery.
  • Chronic exposure to exercise training results in adaptations in the neuroendocrine system, such that there is a reduction in hormonal stress response to submaximal exercise and, in many cases, reduced circulating basal stress hormone levels. This abatement of the hormonal stress response with exercise training has implications for dealing with many chronic stress-related health problems.
  • The adaptability and plasticity in the neuroendocrine system to exercise training has limits. Excessive exercise training can push the neuroendocrine exercise stress response to become inappropriate, resulting in the potential development of chronic fatigue and the overtraining syndrome condition.

 

STRRIDE-AT/RT – Exercise Study

I was considering dropping CrossFit in favor of a strength program when I came across an interesting study which compared Aerobic Training (AT) to Resistance Training (RT) for impact on Metabolic Syndrome (MS). (September 15, 2011, Volume 108, Issue 6, Pages 838–844. Comparison of Aerobic Versus Resistance Exercise Training Effects on Metabolic Syndrome (from the Studies of a Targeted Risk Reduction Intervention Through Defined Exercise – STRRIDE-AT/RT. Lori A. Bateman, Cris A. Slentz, PhD, Leslie H. Willis, MS, A. Tamlyn Shields, MS, Lucy W. Piner, MS, Connie W. Bales, PhD, RD, Joseph A. Houmard, PhD, William E. Kraus, MD.)

AT/RT induced a significant improvement in the MS z score (p = 0.004) and AT alone exhibited a trend toward improvement (p <0.07). However, RT alone failed to significantly alter the MS z score.

My conclusion is to stick with CrossFit and work in the resistance training as often as reasonable as an accessory to CrossFit.

Another view of the same data (J Appl Physiol (1985). 2015 Jun 15;118(12):1474-82. The effects of aerobic, resistance, and combination training on insulin sensitivity and secretion in overweight adults from STRRIDE AT/RT: a randomized trial. Abou Assi H, Slentz CA, Mikus CR, Tanner CJ, Bateman LA, Willis LH, Shields AT, Piner LW, Penry LE, Kraus EA, Huffman KM, Bales CW, Houmard JA, Kraus WE.). Conclusion:

AT/RT resulted in greater improvements in insulin sensitivity, β-cell function (disposition index), and glucose effectiveness than either AT or RT alone (all P < 0.05). Approximately 52% of the improvement in insulin sensitivity by AT/RT was retained 14 days after the last exercise training bout. Neither AT or RT led to acute or chronic improvement in sensitivity index. In summary, only AT/RT (which required twice as much time as either alone) led to significant acute and sustained benefits in insulin sensitivity.

Yet another look at the same data (Am J Physiol Endocrinol Metab. 2011 Nov;301(5):E1033-9. doi: 10.1152/ajpendo.00291.2011. Epub 2011 Aug 16.
Effects of aerobic vs. resistance training on visceral and liver fat stores, liver enzymes, and insulin resistance by HOMA in overweight adults from STRRIDE AT/RT. Slentz CA, Bateman LA, Willis LH, Shields AT, Tanner CJ, Piner LW, Hawk VH, Muehlbauer MJ, Samsa GP, Nelson RC, Huffman KM, Bales CW, Houmard JA, Kraus WE.) concluded:

AT was more effective than RT at improving visceral fat, liver-to-spleen ratio, and total abdominal fat (all P < 0.05) and trended toward a greater reduction in liver fat score (P < 0.10). The effects of AT/RT were statistically indistinguishable from the effects of AT. These data show that, for overweight and obese individuals who want to reduce measures of visceral fat and fatty liver infiltration and improve HOMA and alanine aminotransferase, a moderate amount of aerobic exercise is the most time-efficient and effective exercise mode.

Yet another view (Arch Intern Med. 2004 Jan 12;164(1):31-9. Effects of the amount of exercise on body weight, body composition, and measures of central obesity: STRRIDE–a randomized controlled study. Slentz CA1, Duscha BD, Johnson JL, Ketchum K, Aiken LB, Samsa GP, Houmard JA, Bales CW, Kraus WE.):

In nondieting, overweight subjects, the controls gained weight, both low-amount exercise groups lost weight and fat, and the high-amount group lost more of each in a dose-response manner. These findings strongly suggest that, absent changes in diet, a higher amount of activity is necessary for weight maintenance and that the positive caloric imbalance observed in the overweight controls is small and can be reversed by a modest amount of exercise. Most individuals can accomplish this by walking 30 minutes every day.

Note none of the results were comparable to the effect on the metabolic syndrome from the Low Carb High Fat diet.

Exercise Equipment

Cast Iron Kettlebells

Weights

Barbells

Power Cage

Hyper/Back Extension Ab Bench

I got more out of my first time on one of these benches than four trips to the Chiropractor.

Pullup Bar

 

Adjusted Weight Standards

On a recent article, I posted a link to Weightlifting Standards. These standards are frankly just plain discouraging to me. And with good reason. They are based on a much younger person and their progress. Fortunately, there’s adjusted standards which take into account age, gender, and weight (Symmetric Strength – Weightlifting Standards). It also allows different rep schemes.

Here are the first three columns (the page has many more categories):

The page defines the columns.

Untrained: The lifter has not trained for strength before. The majority of the population. Strength score 30.
Novice: The lifter is stronger than the average untrained lifter of the same sex and weight. Lifters in this category have typically been training for a few months or more. Strength score 45.
Intermediate: The lifter has been consistently training, likely for at least a year. The majority of those who go to the gym regularly fall into this category. Strength score 60.

Weightlifting Standards

One Rep Max (1 RM)

[Edited 2018-01-30 –
Here are a better set of standards which are age adjusted
].

In weightlifting the maximum weight that a person can do of a particular lift is called a One Rep Max (1 RM). There are standards for the 1 RM which are divided by levels of training (Weightlifting Performance Standards). These standards are also divided by gender and body weight. So, for instance, a male who weighs 181 lbs and is untrained should be able to deadlift 150 lbs. This is helpful for determining the weight a beginner should be lifting as well as the progressions they they should be making/should expect. As that same person moves from Untrained to Novice he should be moving from the 150 lbs to 275 lbs.

Levels of Training

From that page:

Untrained

An individual who has not trained on the exercises before, but can perform them correctly. This is the minimum level of strength required to maintain a reasonable quality of life.

Novice

An individual who has trained regularly for up to several months. This level of strength allows for the demands of vigorous recreational activities.

Higher levels are beyond the discussions in this page.

Rep Scaling

There are calculators which can be used to predict a One Rep max based on the number of lbs lifted in a larger set. So, for example, if you can do 5 reps unbroken of 65 lbs that corresponds to a one rep max of 73 lbs. Here are the various numbers this corresponds to:

At CrossFit they list a prescribed (Rx) weight for males and females. These are based on a 1 RM (1 rep max). There is a single number prescribed for males and a different, single number prescribed for females.

 

Body Recomposition Series

My Body Recomposition series is on my Low Carb Studies BLOG.

In the series I set a number of goals for my body composition and means to achieve the goals. Looking back I did really well at hitting what were very aggressive goals.

  1. Improve HbA1C number (HbA1C is a lab test which shows the Blood Sugar over the previous three months)
    Goal: < 5.6 (Below bottom of Pre-Diabetic levels)
    I achieved 5.2 which is non-diabetic.
  2. Lose weight to reach 15% Body Fat (Visualize Body Fat percentages)
    I ended up at 7.5% body fat per Bod Pod.
  3. Barring any injury, be able to do exercise throughout entire test (CrossFit)
    Submaximally is OK (<85% of max level)
    I did this goal through June 2018 but was not able to exercise at a low enough level due to the competitive nature of Crossfit.
  4. Conserve current LBM (Lose Weight but not muscle)
    Possibly add LBM?
    Bod Pod shows I did gain LBM over that period.
  5. Maintain current metabolic levels.
    The same thing as saying not to eat at a net calorie deficit.
    I think the goal was correct (my TDEE is equal to my pre-diet TDEE due to higher exercise energy expenditure). But I had to have been at a significant caloric deficit because I lost quite a bit more weight.

 

Exercise Studies

This will be an accumulated list of exercise related studies.

Athletic performance on Low Carb

Exercise and Diabetes

Exercise Physiology (Mechanisms)

Exercise Supplementation

 

Splitting Low Carb Studies BLOG into Two Sites

The Low Carb Studies BLOG is being split into two sites. The original Low Carb Studies BLOG will concentrate on the Low Carb/Ketogenic diet. This site will focus on Athletics on the Ketogenic Diet.

It will take a while to move the content over but allow more focus on each subject individually.