The Relationship Between Perceived Exertion and Heart Rate During Yoga

The relationship between perceived exertion and heart rate during yoga Jessica Michele Flores, John D. Smith, Ph.D. Texas A&M University-San Antonio Undergraduate Yoga has been around for centuries and has steadily increased in popularity in the West through the years, but this mind-body-spirit practice has had very little research conducted perceived intensities. PURPOSE: to assess heart rate (HR) and rating of perceived exertion (RPE) of those participating in yoga classes. It is hypothesized that as HR increases, there will also be in increase in RPE. It is also hypothesized that those taking yoga classes have goals of flexibility and stress reduction rather than weight reduction and strength. METHODS: Thirty-one participants (age = 30.8±12.0 yrs, ht = 163.0±6.3 cm, wt = 74.4±17.7 kg, BMI = 27.9±6.3) were fitted with a Polar HR monitor and instructed on how to use the Borg’s 6-20 RPE scale. At the start of a 60-minute session HR was recorded. At minutes 15, 30, 45, and 60 HR and RPE were recorded. At these time-points, the investigator simply looked at the receiver and participants pointed to a number on the RPE scale. Immediately following the class, participants completed a survey that included questions about yoga and demographic data. A Pearson’s product moment correlation was used to determine the relationship between HR and RPE, with significance set at .05. Surveys were tallied to determine participant’s goals. RESULTS: Although there was a significant correlation between HR and RPE at minute 45 (r(30) = .44, p = .014), only 20% of the variance in the increase in RPE can be attributed to the increase in HR. This trend also occurred at minute 60 (r(30) = .38, p = .036), but with only 14% of the change in RPE due to the change in HR. Correlations between HR and RPE at minutes 15 and 30 were not significant (p \u3e .05). While half of the participants rated flexibility as their number one reason for participating in yoga, 16% of participants rated “aerobic” as their number one reason for participating. Ninety percent of participants felt more relaxed at the end of a yoga class. CONCLUSIONS: This study suggests that it is best to use caution using the Borg’s 6-20 scale to measure exercise intensity during yoga. There is evidence to show that there may be a misconception in using yoga for aerobic benefits. There is also evidence that show many people believe flexibility and stress reduction are key benefits of yoga

Genetic variation of the prion protein gene (PRNP) in alpaca (Vicugna pacos)

Transmissible spongiform encephalopathies (TSE) are caused by accumulation of a misfolded form of the prion protein (PrP). The normal cellular isoform of PrP is produced by the prion gene (PRNP) and is highly expressed in the central nervous system. Currently, there is an absence of information regarding the genetic sequence of alpaca PRNP and the potential susceptibility of this species to TSE. The objective of this study was to sequence the open reading frame of the alpaca prion gene and analyze this sequence for variation within the alpaca population and for homology to TSE-susceptible species. We sequenced the open reading frame of the prion gene of 40 alpacas of Huacaya or Suri descent. Length polymorphisms were identified within the sampled population. A subset (15%) of animals contained an additional 24 base pairs within the putative octapeptide repeat region. This polymorphism was independent of breed and sex. The majority (52.5%) of animals were heterozygous, possessing both longer and shorter alleles. Comparison with proven TSE-susceptible species (sheep, cattle, deer) revealed the following amino acid sequence variations: I6M, A16V, M17T, G92del, Q95_G96insG, N111S, R167K, N/T177S, I206V, S225Y, Y228S, Q230G, and L237del. Sequence alignment showed high homology compared to camel (\u3e 95%), sheep (\u3e 88%), cattle (\u3e 87%) and deer (\u3e 88%) PRNP sequence. This study demonstrates intraspecies variability within the PRNP open reading frame in alpacas and overall high sequence homology to TSE-susceptible species, providing foundational data for further research on the potential susceptibility of alpacas to TSE

International Society of Sports Nutrition position stand: meal frequency

Position Statement: Admittedly, research to date examining the physiological effects of meal frequency in humans is somewhat limited. More specifically, data that has specifically examined the impact of meal frequency on body composition, training adaptations, and performance in physically active individuals and athletes is scant. Until more research is available in the physically active and athletic populations, definitive conclusions cannot be made. However, within the confines of the current scientific literature, we assert that:1. Increasing meal frequency does not appear to favorably change body composition in sedentary populations.2. If protein levels are adequate, increasing meal frequency during periods of hypoenergetic dieting may preserve lean body mass in athletic populations.3. Increased meal frequency appears to have a positive effect on various blood markers of health, particularly LDL cholesterol, total cholesterol, and insulin.4. Increased meal frequency does not appear to significantly enhance diet induced thermogenesis, total energy expenditure or resting metabolic rate.5. Increasing meal frequency appears to help decrease hunger and improve appetite control.The following literature review has been prepared by the authors in support of the aforementioned position statement

A Limousin Specific Myostatin Allele Affects Longissimus Muscle Area and Fatty Acid Profiles in a Wagyu-Limousin F2 Population

A microsatellite-based genome scan of a Wagyu x Limousin F(2) cross population previously demonstrated QTL affecting LM area and fatty acid composition were present in regions near the centromere of BTA2. In this study, we used 70 SNP markers to examine the centromeric 24 megabases (Mb) of BTA2, including the Limousin-specific F94L myostatin allele (AB076403.1; 415C \u3e A) located at approximately 6 Mb on the draft genome sequence of BTA2. A significant effect of the F94L marker was observed (F = 60.17) for LM area, which indicated that myostatin is most likely responsible for the effect. This is consistent with previous reports that the substitution of Leu for Phe at AA 94 of myostatin (caused by the 415C \u3e A transversion) is associated with increased muscle growth. Surprisingly, several fatty acid trait QTL, which affected the amount of unsaturated fats, also mapped to or very near the myostatin marker, including the ratio of C16:1 MUFA to C16:0 saturated fat (F = 16.72), C18:1 to C18:0 (F = 18.88), and total content of MUFA (F = 17.12). In addition, QTL for extent of marbling (F = 14.73) approached significance (P = 0.05), and CLA concentration (F = 9.22) was marginally significant (P = 0.18). We also observed associations of SNP located at 16.3 Mb with KPH (F = 15.00) and for the amount of SFA (F = 12.01). These results provide insight into genetic differences between the Wagyu and Limousin breeds and may lead to a better tasting and healthier product for consumers through improved selection for lipid content of beef

Genetic variation of the prion protein gene (PRNP) in alpaca (Vicugna pacos)

Transmissible spongiform encephalopathies (TSE) are caused by accumulation of a misfolded form of the prion protein (PrP). The normal cellular isoform of PrP is produced by the prion gene (PRNP) and is highly expressed in the central nervous system. Currently, there is an absence of information regarding the genetic sequence of alpaca PRNP and the potential susceptibility of this species to TSE. The objective of this study was to sequence the open reading frame of the alpaca prion gene and analyze this sequence for variation within the alpaca population and for homology to TSE-susceptible species. We sequenced the open reading frame of the prion gene of 40 alpacas of Huacaya or Suri descent. Length polymorphisms were identified within the sampled population. A subset (15%) of animals contained an additional 24 base pairs within the putative octapeptide repeat region. This polymorphism was independent of breed and sex. The majority (52.5%) of animals were heterozygous, possessing both longer and shorter alleles. Comparison with proven TSE-susceptible species (sheep, cattle, deer) revealed the following amino acid sequence variations: I6M, A16V, M17T, G92del, Q95_G96insG, N111S, R167K, N/T177S, I206V, S225Y, Y228S, Q230G, and L237del. Sequence alignment showed high homology compared to camel (> 95%), sheep (> 88%), cattle (> 87%) and deer (> 88%) PRNP sequence. This study demonstrates intraspecies variability within the PRNP open reading frame in alpacas and overall high sequence homology to TSE-susceptible species, providing foundational data for further research on the potential susceptibility of alpacas to TSE.This article is published as Vermette, M. S., J. A. Schleining, J. J. Greenlee, and J. D. Smith. "Genetic variation of the prion protein gene (PRNP) in alpaca (Vicugna pacos)." Gene Reports 4 (2016): 213-217. doi: 10.1016/j.genrep.2016.06.004. </p

A Limousin Specific Myostatin Allele Affects Longissimus Muscle Area and Fatty Acid Profiles in a Wagyu-Limousin F2 Population

A microsatellite-based genome scan of a Wagyu x Limousin F(2) cross population previously demonstrated QTL affecting LM area and fatty acid composition were present in regions near the centromere of BTA2. In this study, we used 70 SNP markers to examine the centromeric 24 megabases (Mb) of BTA2, including the Limousin-specific F94L myostatin allele (AB076403.1; 415C > A) located at approximately 6 Mb on the draft genome sequence of BTA2. A significant effect of the F94L marker was observed (F = 60.17) for LM area, which indicated that myostatin is most likely responsible for the effect. This is consistent with previous reports that the substitution of Leu for Phe at AA 94 of myostatin (caused by the 415C > A transversion) is associated with increased muscle growth. Surprisingly, several fatty acid trait QTL, which affected the amount of unsaturated fats, also mapped to or very near the myostatin marker, including the ratio of C16:1 MUFA to C16:0 saturated fat (F = 16.72), C18:1 to C18:0 (F = 18.88), and total content of MUFA (F = 17.12). In addition, QTL for extent of marbling (F = 14.73) approached significance (P = 0.05), and CLA concentration (F = 9.22) was marginally significant (P = 0.18). We also observed associations of SNP located at 16.3 Mb with KPH (F = 15.00) and for the amount of SFA (F = 12.01). These results provide insight into genetic differences between the Wagyu and Limousin breeds and may lead to a better tasting and healthier product for consumers through improved selection for lipid content of beef.This article is from Journal of Animal Science 87 (2009): 1576, doi:10.2527/jas.2008-1531.</p