There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Thank you for downloading textbook of work physiology physiological bases of exercise. As you may know, people have look hundreds times for their chosen novels like this textbook of work physiology physiological bases of exercise, but end up in infectious downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they cope with some harmful virus inside their desktop computer.

Textbook Of Work Physiology Physiological Bases Of Exercise

Myostatin, a member of the transforming growth factor-β (TGF-β) superfamily, has been shown to be a negative regulator of myogenesis. Here we show that myostatin functions by controlling the proliferation of muscle precursor cells. When C2C12 myoblasts were incubated with myostatin, proliferation of myoblasts decreased with increasing levels of myostatin. Fluorescence-activated cell sorting analysis revealed that myostatin prevented the progression of myoblasts from the G1- to S-phase of the cell cycle. Western analysis indicated that myostatin specifically up-regulated p21Waf1, Cip1, a cyclin-dependent kinase inhibitor, and decreased the levels and activity of Cdk2 protein in myoblasts. Furthermore, we also observed that in myoblasts treated with myostatin protein, Rb was predominately present in the hypophosphorylated form. These results suggests that, in response to myostatin signaling, there is an increase in p21 expression and a decrease in Cdk2 protein and activity thus resulting in an accumulation of hypophosphorylated Rb protein. This, in turn, leads to the arrest of myoblasts in G1-phase of cell cycle. Thus, we propose that the generalized muscular hyperplasia phenotype observed in animals that lack functional myostatin could be as a result of deregulated myoblast proliferation.

Myostatin, a negative regulator of muscle growth, functions by inhibiting myoblast proliferation.

Sarcopenia

This review summarizes the current body of knowledge on the main biological mediators (ingredients) of the preventive/therapeutic effects of regular exercise.

/pdf/exercise-is-the-real-polypill-3rjx0g9ise.pdf

Exercise is the Real Polypill

Powerful signals for weak muscles.

PURPOSE:
This study aimed to determine the effect of passive insulation versus external heating during recovery following a sprint specific warm up on thigh muscle temperature and subsequent maximal sprint performance.

METHODS:
On three separate occasions, 11 male cyclists (age 24.7 ± 4.2 years, height 1.82 ± 0.72m, body mass 77.9 ± 9.8 kg; mean ± S.D.) completed a standardized 15 min intermittent warm up on a cycle ergometer, followed by a 30 min passive recovery period before completing a 30 sec maximal sprint test. Muscle temperature was measured in the vastus lateralis at 1, 2 and 3 cm depth prior to and following the warm up and immediately before the sprint test. Absolute and relative peak power output was determined and blood lactate concentration was measured immediately post-exercise. During the recovery period participants wore a tracksuit top and either i) standard tracksuit pants (CONT); ii) insulated athletic pants (INS) or; iii) insulated athletic pants with integrated electric heating elements (HEAT).

RESULTS:
Warm up increased Tm by approximately 2.5°C at all depths, with no differences between conditions. During recovery, Tm remained elevated in HEAT compared to INS and CONT at all depths (p<0.001). Both peak and relative power output were elevated by 9.6% and 9.1% respectively in HEAT compared to CONT (both p<0.05). The increase in blood lactate concentration was greater (p<0.05) post sprint in HEAT (6.3 ± 1.8 mmol/L) but not INS (4.0 ± 1.8 mmol/L) vs. CONT (4.1 ± 1.9 mmol/L).

CONCLUSION:
Passive heating of the thighs between warm up completion and performance execution using pants incorporating electrically heated pads can attenuate the decline in Tm and improve sprint cycling performance.

/pdf/reducing-muscle-temperature-drop-after-warm-up-improves-4b3u48kf1b.pdf

Reducing muscle temperature drop after warm-up improves sprint cycling performance

The interaction effects of tumour necrosis factor-alpha (TNF-alpha) and interlukin-6 (IL-6) on skeletal muscle proliferation and differentiation remains controversial. We therefore investigated the potential interactive effects of TNF-alpha and IL-6 on murine C2 skeletal myoblast survival, differentiation and proliferation. A novel and unexpected positive temporal interaction between TNF-alpha and IL-6 on cell growth was identified (90%), with maximal beneficial effects obtained in myoblasts treated with TNF-alpha (10 ng/ml) for 24 h prior to being dosed with IL-6 (2.5 ng/ml) for a further 24 h. This combined treatment significantly (p < 0.05) increased the level of total cellular protein (330%), extracellular signal-regulated kinase (ERK) phosphorylation (55%), and S-phase of cell cycle (2.5-fold), confirming cell growth. The expression of mRNAs of key regulators of muscle mass: insulin-like growth factor binding protein-5, insulin-like growth factor-II (IGF-II), IGF-I receptor (IGF-IR) and IGF-II receptor (IGF-IIR) were also significantly (p < 0.05) increased by 1600-, 1.6-, 27- and 6-fold, respectively, giving an indication of the regulatory mechanisms of this interaction. Moreover, in response to this treatment, the expression level of signal-transducing glycoprotein 130 (gp130) was induced up to 3.5-fold but not after either treatments alone. This may not only explain the beneficial effects of this treatment on skeletal myoblast numbers but also define a functional role of gp130 in skeletal muscle cells. Our data suggest that in the presence of TNF-alpha/IL-6 functions positively and potentially also cooperatively with the IGF system to achieve the maximal beneficial effect on skeletal myoblast numbers.

Beneficial synergistic interactions of TNF-α and IL-6 in C2 skeletal myoblasts—Potential cross-talk with IGF system

A single hot water immersion (HWI) session induces an acute increase in plasma interleukin-6 and nitrite concentrations but does not acutely elevate heat shock protein-72 expression in monocytes [i...

https://www.physiology.org/doi/pdf/10.1152/japplphysiol.00407.2018

Acute and chronic effects of hot water immersion on inflammation and metabolism in sedentary, overweight adults

Increasing physical activity remains the most widely publicized way of improving health and wellbeing. However, in populations that benefit most from exercise (EX), adherence is often poor and alternatives to EX are important to bring about health improvements. Recent work suggests a role for passive heating (PH) and heat shock proteins (HSP) in improving cardio-metabolic health. The aim of this study was to investigate the expression of HSP70 and interleukin-6 in response to either EX or PH and the subsequent effect on glucose control. Fourteen males volunteered and were categorized lean (BMI 23.5 ± 2.2 kg·m−2) or overweight (29.2 ± 2.7 kg·m−2) and completed 60 minutes of either moderate cycling at a fixed rate of metabolic heat production (EX) or warm water immersion in 40°C water (PH). Extracellular HSP70 increased from baseline in both conditions with no differences between PH (0.98 ± 1.1 ng·mL−1) or EX (0.84 ± 1.0 ng·mL−1, p = 0.814). IL-6 increased following both conditions with a two-fold i...

https://www.tandfonline.com/doi/pdf/10.1080/23328940.2017.1288688

Steve H. Faulkner

Papers

Powerful signals for weak muscles.

Reducing muscle temperature drop after warm-up improves sprint cycling performance

Beneficial synergistic interactions of TNF-α and IL-6 in C2 skeletal myoblasts—Potential cross-talk with IGF system

Acute and chronic effects of hot water immersion on inflammation and metabolism in sedentary, overweight adults

The effect of passive heating on heat shock protein 70 and interleukin-6: A possible treatment tool for metabolic diseases?