Composizione corporea, nutrizione personalizzata e costo energetico della corsa: studio longitudinale su una popolazione di individui fisicamente attivi

Considering the relation between body weight-composition and energy cost of running, we tested the hypothesis that modifying body composition by means of a combined protocol of specific diet and training, the energy cost of motion (Cr) may be reduced. 45 healthy and normal-weight subjects were divided into three groups that performed a different treatment: the first group attended only a dietary protocol (D), the second only a running program (R) and the third both (R&D). Each subject underwent three anthropometric and exercise evaluation tests during one year (at T0, T6, T12) to assess body composition and Cr adjustments. The mean fat mass (FM) values were reduced in R&D from 12.0±4.0 to 10.4±3.0 kg (p<0.05 T0 vs. T12) and in the D group from 14.2±5.8 to 11.6±4.7 kg (p<0.05 T0 vs. T12). Conversely, the mean fat free mass values increased in R&D (from 56.3±8.8 to 58.3±9.8 kg, p<0.05 T0 vs. T12) and in the D group (from 50.6±13.2 to 52.9±13.6 kg, p<0.05 T0 vs. T12). The mean Cr values of the 2 groups were significantly modified throughout the one year protocol (1.48±0.16 and 1.40±0.15 kcal·kg-b·km-1 in the R&D group at T0 and T12 respectively; 1.83±0.17 and 1.76±0.23 kcal·kg-b·km-1 in D group at T0 to T12 respectively). The R&D and D groups that underwent the diet protocol had a positive change in body composition during the year (FM-fat free mass ratio decline) which determined a Cr reduction

LivDet in Action - Fingerprint Liveness Detection Competition 2019

The International Fingerprint liveness Detection Competition (LivDet) is an open and well-acknowledged meeting point of academies and private companies that deal with the problem of distinguishing images coming from reproductions of fingerprints made of artificial materials and images relative to real fingerprints. In this edition of LivDet we invited the competitors to propose integrated algorithms with matching systems. The goal was to investigate at which extent this integration impact on the whole performance. Twelve algorithms were submitted to the competition, eight of which worked on integrated systems.Comment: Preprint version of a paper accepted at ICB 201

Cardiovascular Responses to Simultaneous Diving and Muscle Metaboreflex Activation

Background: The aim of study was to assess hemodynamic changes during the simultaneous activation of muscle metaboreflex (MM) and diving reflex (DR) in a laboratory setting. We hypothesized that as long as the exercise intensity is mild DR can overwhelm the MM. Methods: Ten trained divers underwent all four phases (randomly assigned) of the following protocol. (A) Postexercise muscle ischemia session (PEMI): 3 min of resting followed by 3 min of handgrip at 30% of maximum force, followed immediately by 3 min of PEMI on the same arm induced by inflating a sphygmomanometer. Three minutes of recovery was further allowed after the cuff was deflated for a total of 6 min of recovery. (B) Control exercise recovery session: the same rest-exercise protocol used for A followed by 6 min of recovery without inflation. (C) DR session: the same rest-exercise protocol used for A followed by 1 min of breath-hold (BH) with face immersion in cold water. (D) PEMI-DR session: the same protocol used for A with 60 s of BH with face immersion in cold water during the first minute of PEMI. Stroke volume (SV), heart rate (HR), and cardiac output (CO) were collected by means of an impedance method. Results: At the end of apnea, HR was decreased in condition C and D with respect to A (−40.8 and −40.3%, respectively vs. −9.1%; p &lt; 0.05). Since SV increase was less pronounced at the same time point (C = +32.4 and D = +21.7% vs. A = +6.0; p &lt; 0.05), CO significantly decreased during C and D with respect to A (−23 and −29.0 vs. −1.4%, respectively; p &lt; 0.05). Conclusion: Results addressed the hypothesis that DR overcame the MM in our setting

Body Composition and Strength Symmetry of Kettlebell Sport Athletes

Kettlebell sport (KBs) is increasingly popular, but very few studies have been focused on this discipline. This research aims to investigate the effects of KBs on body composition, strength symmetry, and segmental body composition symmetry in a sample of Italian elite athletes. Data were collected from a sample of 16 athletes of both sexes (11 men and 5 women; 34.5 ± 9.0 years of age). Anthropometric (height, weight, arm, thigh, calf, and waist circumferences), hand grip strength, and total and segmental bioelectrical variables were taken. Body composition was analysed by using specific bioelectrical impedance vector analysis (BIVA). Paired t-tests and confidence ellipses were applied to analyse bilateral differences. Elite athletes of both sexes showed high values of phase angle, indicative of high body cell mass and quality and proxy of muscle mass. Hand grip strength and body composition were symmetrical, with the only exception of a higher %FM in the right leg (Zsp: t = 3.556; p = 0.003). In conclusion, this study suggests that KBs contributes to muscle mass improvement, body composition, and strength symmetry, especially in the upper body

Diving response after a one-week diet and overnight fasting

Background: We hypothesized that overnight fasting after a short dietary period, especially with carbohydrates, could allow performing breath-hold diving with no restraint for diaphragm excursion and blood shift and without any increase of metabolism, and in turn improve the diving response. Methods: During two separate sessions, 8 divers carried out two trials: (A) a 30-m depth dive, three hours after a normal breakfast and (B) a dive to the same depth, but after following a diet and fasting overnight. Each test consisted of 3 apnea phases: descent, static and ascent whose durations were measured by a standard chronometer. An impedance cardiograph, housed in an underwater torch, provided data on trans-thoracic fluid index (TFI), stroke volume (SV), heart rate (HR) and cardiac output (CO). Mean blood pressure (MBP), arterial O-2 saturation (SaO(2)), blood glucose (Glu) and blood lactate (BLa) were also collected. Results: In condition B, duration of the static phase of the dive was longer than A (37.8 +/- 7.4 vs. 27.3 +/- 8.4 s respectively, P < 0.05). In static phases, mean Delta SV value (difference between basal and nadir values) during fasting was lower than breakfast one (-2.6 +/- 5.1 vs. 5.7 +/- 7.6 ml, P < 0.05). As a consequence, since mean. HR values were equally decreased in both metabolic conditions, mean. CO value during static after fasting was lower than the same phase after breakfast (-0.4 +/- 0.5 vs. 0.4 +/- 0.5 L . min(-1) respectively, P < 0.05). At emersion, despite the greater duration of dives during fasting, SaO(2) was higher than A (92.0 +/- 2.7 vs. 89.4 +/- 2.9 % respectively, P < 0.05) and BLa was lower in the same comparison (4.2 +/- 0.7 vs. 5.3 +/- 1.1 mmol L-1, P < 0.05). Conclusions: An adequate balance between metabolic and splancnic status may improve the diving response during a dive at a depth of 30 m, in safe conditions for the athlete's healt

Mean blood pressure assessment during post-exercise: Result from two different methods of calculation

At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP) is usually calculated with a standard formula (SF) as follows: MBP = diastolic blood pressure (DBP) + 1/3 [systolic blood pressure (SBP) – DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF) which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by –4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg). Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation

BODY COMPOSITION CHANGES AND EATING BEHAVIOR IN RECREATIONAL MALE IRONMAN TRIATHLETES

Introduction Ironman triathletes appear to profit from low body fat (Knechtle et Al. 2011). The aim of this study was to investigate eating habits and body composition in a group of recreational male Ironman, who were in the preparing season for an imminent competition. They trained for about 20 hours/week. Methods Five recreational male Ironman triathletes participated in the study. Each of them completed a food frequency questionnaire (FFQ) to assess their usual diet (Fidanza et Al.,1995) and attended a small interview, so that their daily physical activity level (PAL) was determined. PAL was obtained by dividing Total Energy Expenditure by Base Metabolic Rate (Black et al. 1995). For each subject Fat Mass percentage (FM%) was detected twice by mean of plicometry: eight and one weeks before the competition (Durnin and Womersley, 1974). Dietary recommendations were given to each of them in order to correct their diet as to perfectly fit their needs in term of calories and nutrients. Results Processing of the FFQ emphasized that energy requirements were not fulfilled. In detail, their PAL was about 2, but there was more than 1000 Kcal difference between average intake and average needs, mostly from calories derived from complex carbohydrates, so that their diet was adjusted to fit their needs. In the second detection, made one week before the race, each participant modified his body composition reducing his FM%. Discussion Results of the present investigation show that the dietary status of our sample of triathletes lacked both in term of food quantity and quality. Taking into account that Iroman competition highly recruit the energetic sources of athletes, it is possible to speculate that they may take advantage from a correction of their eating habit by a proper dietary counseling. References Knechtle B, Knechtle P, Rüst CA, Rosemann T (2011)J Sports Sci, 29(13);1373-80 Fidanza F, Gentile MG, Porrini M. (1995), Eur J Epidemiol, 11;163- 170 Black AE, Coward WA, Cole TJ, Prentice AM, (1996) Eur J Clin Nutr, 50 (2); 72-92. Durnin JV, Womersley J (1974), Br J Nutr, 32(1);77-97

Evaluation of reliability of field tests to predict performance during Ironman Triathlon

The reliability of functional evaluation tests to predict performance in Ironman contests is scarce and the results are often equivocal. The purpose of this study was to identify which pre-competition test could best predict Ironman competition outcome. Seven male tri-athletes were recruited 6–8 weeks prior to Ironman Austria. Each athlete performed two maximal incremental tests on the field, a cycling (test A), and a running test (test B). Correlation between cycling and running mean speed during Ironman phases and oxygen uptake (VO2), carbon dioxide production (VCO2), pulmonary ventilation (V E), heart rate (HR), oxygen pulse (OP) and cost of motion (C m), collected during tests, was demonstrated. Significant correlation was found for VO2 at respiratory compensation point (RCP) (r 2 = 0.73; P < 0.05) and at peak exercise (r 2 = 0.73; P < 0.05) during the test. Moreover, V E showed significant correlation both at RCP (r 2 = 0.73; P < 0.05) and at peak exercise (r 2 = 0.61; P < 0.05) values reached during the test. Mean cycling speed and OP values at RCP and peak exercise during test A showed significant correlation (r 2 = 0.76; P < 0.05 and r 2 = 0.87; P < 0.05, respectively). The C m value at RCP during test A demonstrated significant correlation (r 2 = 0.67; P < 0.05). No correlation between mean running speed during the running fraction of the Ironman and any of the variables collected during test B was demonstrated. The results of the present investigation suggest that pre-competition evaluation tests are of limited use to predict competition outcome

Occurrence of cardiac output decrease (via stroke volume) is more pronounced in women than in men during prolonged dry static apnea.

Little is known about sex differences in autonomic cardiovascular regulation of the diving response, and the few available studies of these differences were conducted on subjects with limited or no diving experience. We examined the influence of sex on hemodynamics during dry static apnea (SA) in eight male and eight female elite divers matched for their breath hold (BH) ability. Hemodynamics was assessed by means of simultaneous echocardiography and impedance cardiography measurements, and arterial pressure and oxygen saturation (SaO2) were also collected. In the first quarter (AP25%) and half (AP50%) of apnea duration cardiac output (CO) showed a more rapid and intense decrease in women than in men (- 43% vs. - 17% during AP25% and - 40% vs. - 19% during AP50%, respectively, P < 0.05). At the same time points, systemic vascular resistance (SVR) increased more in women than in men (+ 22% vs. +100% at AP25% and +48% vs. +107% at AP50%, respectively, P < 0.05). SaO2 progressively declined in both groups, but men showed a more pronounced decrease than women at the end of apneas (- 13% vs. - 5%, respectively, P < 0.05). In men the higher the body surface area values the longer the apnea, while in women the higher the SVR response the longer the apnea. In elite female divers, the magnitude of CO decrease during dry SA was larger than in male divers. The capacities to store oxygen and to reduce O2 consumption play a pivotal role in BH performance, but their extent seems to be different in the sexes