Ground Up Strength

Oxidative Stress From Exercise

The topic of exercise-induced oxidative stress has received considerable attention in recent years, with close to 300 original investigations published since the early work of Dillard and colleagues in 1978. Single bouts of aerobic and anaerobic exercise can induce an acute state of oxidative stress. This is indicated by an increased presence of oxidized molecules in a variety of tissues. Exercise mode, intensity, and duration, as well as the subject population tested, all can impact the extent of oxidation. Moreover, the use of antioxidant supplements can impact the findings. Although a single bout of exercise often leads to an acute oxidative stress, in accordance with the principle of hormesis, such an increase appears necessary to allow for an up-regulation in endogenous antioxidant defenses. This review presents a comprehensive summary of original investigations focused on exercise-induced oxidative stress. This should provide the reader with a well-documented account of the research done within this area of science over the past 30 years.

Continue Reading » Oxidative Stress From Exercise

Understanding Normal, Injured and Healing Ligaments And Tendons

Ligaments and tendons are soft connective tissues which serve essential roles for biomechanical function of the musculoskeletal system by stabilizing and guiding the motion of diarthrodial joints. Nevertheless, these tissues are frequently injured due to repetition and overuse as well as quick cutting motions that involve acceleration and deceleration. These injuries often upset this balance between mobility and stability of the joint which causes damage to other soft tissues manifested as pain and other morbidity, such as osteoarthritis.

Continue Reading » Understanding Normal, Injured and Healing Ligaments And Tendons

Muscle Fiber Type: Contractile and Metabolic Properties

Skeletal muscle demonstrates a remarkable plasticity, adapting to a variety of external stimuli (Booth and Thomason 1991; Chibalin et al. 2000; Hawley 2002; Flück and Hoppeler 2003), including habitual level of contractile activity (e.g., endurance exercise training), loading state (e.g., resistance exercise training), substrate availability (e.g., macronutrient supply), and the prevailing environmental conditions (e.g., thermal stress). This phenomenon of plasticity is common to all vertebrates (Schiaffino and Reggiani 1996). However, there exists a large variation in the magnitude of adaptability among species, and between individuals within a species. Such variability partly explains the marked differences in aspects of physical performance, such as endurance or strength, between individuals, as well as the relationship of skeletal muscle fiber type composition to certain chronic disease states, including obesity and insulin resistance.

Continue Reading » Muscle Fiber Type: Contractile and Metabolic Properties

Overuse Injuries in Female Athletes

The last three decades have witnessed a tremendous increase in female sports participation at all levels. However, increased sports participation of female athletes has also increased the incidence of sport-related injuries, which can be either acute trauma or overuse injuries. Overuse injuries may be defined as an imbalance caused by overly intensive training and inadequate recovery, which subsequently leads to a breakdown in tissue reparative mechanisms. This article will review the most frequent overuse injuries in female athletes in the context of anatomical, physiological, and psychological differences between genders.

Continue Reading » Overuse Injuries in Female Athletes

Fight Or Flight: Lift or Die?

Have You ever heard someone say that in order to lift a very heavy load they imagine they are "doing battle" with the bar? Of course the real hardcore lifters don't say the word bar, they say "iron". "It's just me and the iron in a battle to the death," they say, or some such similar nonsense.¹

Continue Reading » Fight Or Flight: Lift or Die?

Paradoxical and Diaphragmatic Breathing

Or..high chest breathing, chest breathing, thoracic breathing, accessory breathing

I began to hit on this in a previous post, On Breathing.... The purpose of that post was to introduce the fallacy of "expanding the chest". To do so I focused on strongmen of old and their ideas about ribcage expansion. Indeed, that was a fetish that followed into the early bodybuilding days and beyond.

Continue Reading » Paradoxical and Diaphragmatic Breathing

Muscle Cramps Part V

In the last article we introduced you to Randy, our imaginary 70 kg average male runner, and we created some potential scenarios regarding his fluid and sodium losses and replacement. The biggest take home message was to listen to your body and to drink to thirst, as this has been shown again and again in the field and the lab to keep people from drinking either too little or too much. We have received tons of feedback and discussion, and as we stated in the comments to that post we are pleased that so many of you are participating in the discussion, sharing your stories, and asking relevant and insightful questions.

Continue Reading » Muscle Cramps Part V

Muscle Cramps Part 4.5

This is a pseudo-Part V of our series on Muscle Cramps - I was tempted to call it Part V, but it's a little bit of a departure from what we've been talking about. In our next article, which we will be calling Part V, we'll wrap up this really challenging series and try to summarize all of the comments and our articles into one concluding piece.

Continue Reading » Muscle Cramps Part 4.5

Theories and Fallacies of Muscle Cramps Part IV: An explanation of the evolution of science

Over the past three articles, we've taken what has turned out to be a pretty intense look at muscle cramps. We began with a discussion of how muscle cramps were first attributed to a low serum electrolyte concentration, without any substantial evidence for this theory. We then moved on to show that, in fact, people who cramped have the SAME electrolyte concentrations and levels of dehydration as those who do not cramp - this is pretty strongly suggestive that cramping is not caused by either dehydration or electrolyte depletion. Then in Part III, we described a new model for muscle cramps, involving a 'malfunction' in the reflex control of muscles during fatigue.

Continue Reading » Theories and Fallacies of Muscle Cramps Part IV: An explanation of the evolution of science

Theories and Fallacies of Muscle Cramps Part III: A Novel Theory for Exercise-associated Muscle Cramps

This marks the the third part of our series on muscle cramps. It was going to be the final installment in this particular series, but we've received some excellent and thoughtful questions and comments on the issue, so have decided that we'll do a fourth article, just summarizing some of those key "sticking" points. It seems from the feedback that this issue - electrolytes and cramps - is one of the more contentious ones around. So in our FOURTH article of the series, we'll look back and try to tie up any loose ends and conceptual issues.

Continue Reading » Theories and Fallacies of Muscle Cramps Part III: A Novel Theory for Exercise-associated Muscle Cramps

Theories and Fallacies of Muscle Cramps Part II: Electrolyte Depletion Model of Muscle Cramps

In part one of this series on muscle cramps we tried to set the scene by providing some history in this area. At times it might seem like we are a bit heavy on the historical side, but as we mentioned in one of our comments to Part I, understanding the historical record is crucial as often it helps us understand why we think what we do—-and this affects one's interpretation of the science. In this article we will focus on the prevailing premise that dehydration and electrolyte disturbances cause muscle cramps.

Continue Reading » Theories and Fallacies of Muscle Cramps Part II: Electrolyte Depletion Model of Muscle Cramps

Endurance Capacity, Not Body Size, Determines Physical Activity Levels: Role of Skeletal Muscle PEPCK

Some people remain lean despite pressure to gain weight. Lean people tend to have high daily activity levels, but the source of this increased activity is unknown. We found that leanness cannot be accounted for by increased weight-corrected food intake in two different types of lean rats. As previously reported in lean people, we found that lean rats had higher daily activity levels; lean rats also expended more energy. These lean rats were developed through artificial selection for high aerobic endurance capacity. To test whether our findings extended to a human population, we measured endurance capacity using a VO2max treadmill test and daily activity in a group of non-exercising individuals. Similar to lean rats selectively bred for endurance capacity, our study revealed that people with higher VO2max also spent more time active throughout the day. Hence, endurance capacity may be the trait that underlies both physical activity levels and leanness. We identified one potential mechanism for the lean, active phenotype in rats, namely high levels of skeletal muscle PEPCK. Therefore, the lean phenotype is characterized by high endurance capacity and high activity and may stem from altered skeletal muscle energetics.

Continue Reading » Endurance Capacity, Not Body Size, Determines Physical Activity Levels: Role of Skeletal Muscle PEPCK

Theories and Fallacies of Muscle Cramps Part I

This is a follow-on from our series of articles on Fluid Intake and Dehydration, and as we were preparing to write this series, we realized that there may actually be even more nonsense and blatant lies in the media than there were for dehydration!

Continue Reading » Theories and Fallacies of Muscle Cramps Part I

Fluid Intake, Dehydration, And Exercise Part IV

So far we investigated the history of fluid ingestion in Part I, demonstrated why it is the metabolic rate that predicts temperature in Part II, and weighed up the strengths and weaknesses of the lab-based and field studies in Part III. For Part IV we will look at the thirst mechanism and why waiting until you are thirsty is not "too late."

Continue Reading » Fluid Intake, Dehydration, And Exercise Part IV

Fluid Intake Dehydration And Exercise Part III

Welcome back for Part III in this series on fluid intake and dehydration during exercise! Thus far we have examined a brief history of fluid replacement during endurance exercise in Article I, and in Article II we tried to explain how some of the lab research has perhaps been over-interpreted, and how that has lead to a false belief that ingesting fluid during exercise will keep you cool. In that article we reported the findings of earlier researchers who concluded the following:

* The core temperature is maintained at a higher level during exercise
* It is the metabolic rate (or in other words, how hard you are exercising) that predicts the core temperature

Continue Reading » Fluid Intake Dehydration And Exercise Part III