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Eccentric, high or low intensity training, the best choice in RunForScience endurance performance
No full textCellular aging of skeletal muscle: evidence that physical inactivity is responsible and not age
No full textTelomeres play an essential role in maintaining chromosomal integrity in the face of physiological stressors. Although the age-related shortening of TL (telomere length) in highly proliferative tissue is predominantly due to the replication process, the mechanism for telomere shortening in skeletal muscle, which is minimally proliferative, is unclear. By studying TL in both the upper and lower limbs of the young, old-mobile and old-immobile subjects and by virtue of the bipedal nature of human locomotion, which declines with age, it may be possible to elucidate the mechanism(s) responsible for cellular aging of skeletal muscle. With this approach, we revealed that TL (~15 kb) in arm skeletal muscle is unaffected by age. In contrast TL fell progressively in the legs across the young (~15 kb), the old mobile (~13 kb) and old immobile (~11 kb) subjects. Interestingly, there was a reciprocal increase in leg muscle free radicals across these groups that was correlated with TL (r=0.7), with no such relationship in the arm (r=0.09). Our results document that chronological age does not affect the cellular aging of skeletal muscle, but reveals that physical inactivity, probably mediated by free radicals, has a profound effect upon this process
EFFECTS OF ECCENTRIC STRENGTH TRAINING IN RUNNING ECONOMY OF RECREATIONAL ENDURANCE RUNNERS
No full textIntroduction Several studies showed the effects of combined strength and endurance training on endurance performance and running
economy (RE). However, few studies investigated specifically the effects of eccentric strength training. Aim of this research was to measure
variation of RE after a combined eccentric strength-endurance training versus low or high intensity endurance training programs.
Methods Twenty-nine well trained recreational runners (average age 35-55y; V’O2max around 50 ml/min/kg) were randomized in 3
training programs: combined eccentric strength-endurance (EST), low intensity endurance (LIT), high intensity training (HIT). Each group
performed 8-week of training, 3 times a week; training volume (time x intensity) was accurately equalized among the groups. Reference
Velocity (RV) as the medium speed between the first and the second ventilatory threshold was used to identify individual training intensity.
RV ranged 95-140% for HIT and 70-105% for LIT and EST groups respectively. EST group, in addition to LIT program, performed once a
week, 4 sets of 7 repetitions of Yo-Yo Leg Press (Yo-Yo Technology Stockholm Sweden). Before and after training each runner underwent
metabolic measurements (Cosmed Quark, Italy) on a treadmill for determination of V’O2max and RE at three submax steady state
speeds. Lower Limb Free Fat Mass (LLFFM) were measured by DXA (Holometric, USA) and leg-press 1RM (Technogym, Italy). Data were
analysed by two way ANOVA and significance level was set at p<0.05. Results The combined endurance and strength training (EST
group) produced significant improvements in RE (pre 4.5±0.3 J/m, post 4.3±0.4 J/m (p ≤ .05) and 1RM leg press (pre 143.8±35.8 kg, post
162.4±37.3kg (p ≤ .05) while no change in RE was found in HIT (pre: 4.6±0.3, post 4.6±0.4 J/m-1) and in LIT (pre: 4.2±0.5, post 4.2±0.3).
V’O2max and LLFFM. Did not show significant modification in any groups. Discussion The data from the present study show a significant
increase of muscle strength with associated reduction of RE in EST group with no concomitant changes in the V’O2max and in the lower
limb muscle mass. These adaptations seem to indicate that short duration eccentric training (one bout/week for about 20min) produces
changes in structural muscle characteristics (fibers, architecture) and intra and inter muscular coordination allowing a reduction in RE in
well trained recreational runners without any reduction in aerobic power. References Turner, AM, Owings, M, and Schwane, JA. J
Strength Cond Res 17: 60–67, 2003. Tesch PA & HE Berg. Int J Sports Med 18:S322-324 (Suppl 4), 1997. Piacentini MF, De Ioannon G,
Comotto S, Spedicato A, Vernillo G, La Torre A. J Strength Cond Res. 2013 Aug;27(8):2295-303 [email protected]
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Determinants of marathon performance : the Run4Science project
No full textIt is well documented that the performance determinants of the endurance performances are the (i) maximal aerobic power (V'O2max), (ii) running economy (RE), (iii) lactate threshold (LT) and (iv) fractional utilization of V’O2max (f) during the race1. These are true both for the high-level and recreational athletes and accounted for about 20%-30%-20%-30%, respectively.
For years, running marathons was considered an odd and potentially dangerous activity. Yet, the increasing popularity of (half)marathon running among humans of all ages and abilities is a testament to the human capability for endurance running, defined as the ability to run long distances using aerobic metabolism2. Through the years, (half)marathon participation has skyrocketed with hundreds of (half)marathons worldwide, with several events having more than 40,000 participants3 (73,000 only in Italy in the 2013). The vast majority of whom are recreational and middle-aged whose train and compete regularly, but most of them according to unstructured and scientifically inaccurate training programs.
The purpose of the Project called ‘Run 4 Science’ was to enlarge upon the analysis both of the different training methologies and factors that may potentially be involved in the (half)marathon performance, bringing together the specific scientific knowledges of four different italian University (Verona, Milan, Rome and Turin) to analyze the effects of two training methodologies (i.e., high intensity trainining and a combined endurance and eccentric strength training) on different psycobiological variables.
49 recreational runners were tested PRE and POST 8 weeks of a training protocol. The variables gathered and analysed were: (i) anthopometric characteristic, (ii) V'O2MAX, (iii) VT1 and VT2, (iv) RE (at 75, 85 and 95% of VT1), (v) maximal strength (1RM), (vi) 2000m run time-trial and (vii) 10.000m run time-trial. Further, PRE and POST the final event [(half)marathon] several other parameters were assessed: (i) pacing strategy, (ii) rate of perceived exertion, (iii) RE, (iv) muscular stiffness, (v) running kinematics, (vi) muscular fatigue, (vii) changes in blood markers and (viii) algesimetry.
The attempt was to help in the advancement of knowledge concerning the training methodologies for the endurance disciplines, suggesting practical and evidence-based application useful for the italian coaches and recommending effective training programs
Energy cost and efficiency of Venetian rowing on a traditional, flat hull boat (Bissa)
No full textThe total net metabolic power output (E, kW) required to scull a traditional, flat hull boat--the "Bissa", 9.02 m long and weighting about 500 kg including the crew-was assessed at different constant speeds (nu) ranging from 2.44 to 3.75 m s(-1). E increased with the speed: E = 0.417 x e (0.664v ); r (2) = 0.931. The amount of metabolic energy spent per unit distance (C, J m(-1)) to move the "Bissa", calculated by dividing E by the corresponding nu, was a linear function of nu: C = 0.369 nu -0.063; r (2) = 0.821. The hydrodynamic resistance met by the boat in the water--drag (D, N)--was estimated by analysing the decay of the reciprocal of nu as a function of time measured during several spontaneous deceleration tests carried out in still water and by knowing the total mass of the watercraft plus crew. D increased as a square function of speed: D = 12.76 v (2). This allowed us to calculate the drag efficiency (g(d)), as the ratio of D to C: g(d) increased from 8.9 to 13.7% in the range of the speeds tested. The "Bissa" turned out to be as economical as other flat hull, traditional watercrafts, such as the bigger Venetian gondola, and her g(d) was similar to that of other modern and traditional watercrafts
Gender differences in neuromuscular fatigue after 21km run
No full textAim: Little is known about the gender differences in fatigue during prolonged locomotor exercise. This study investigated possible gender differences in central and peripheral fatigue and in the rate of force development in the knee extensor muscles after 21 km run. Methods: Ten males and eight females amateur runners (aged 25 to 50 years) were evaluated before and immediately after the “Run for Science” 21 km race. Knee extensors forces were obtained under voluntary and electrically evoked isometric contractions. Maximal voluntary isometric contraction (MVC), rate of force development (RFD), and relative RFD (i.e. RFD/MVC) were obtained. Electrically elicited twitches were recorded during MVC [interpolated twitch (IT)] and at rest [resting twitch (RT)], and the level of voluntary activation (VA) during each MVC was calculated as VA(%)=100(1-IT/RT). Electromechanical delays (EMD) were calculated as the difference between the onset of electromyographic activity in vastus lateralis and the onset of force production. Results: Changes in most neuromuscular variables were found similar between males (former values) and females (latter values), such as MVC (-14%, - 11%, p=0.41), RFD (-20%, -11%, p=0.24), relative RFD (-1%, - 7%, p=0.14), voluntary activation (-7%, -4%, p=0.54), and resting twitch (+ 2%, - 8%, p=0.20). The EMD showed different behaviours between genders (p=0.02) since were found increased in females (+20%) and decreased in males (-19%). Conclusions: Contrary to the expectation, no difference in voluntary force expressions (MVC and RFD) was observed between genders. Otherwise, it was expected the absence of difference in central and peripheral fatigue between genders. The greater impairment of electromechanical delay in females than in males was a novel results for this type of prolonged running. The small sample size may have limited the capacity to distinguish between groups
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