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  • Author: Kamil Michalik x
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Abstract

Introduction. Since mountain biking involves exercise of varying intensity, competitive performance may be affected by the rate of recovery. The aim of the current study was to determine whether maximal oxygen uptake is associated with the rate of heart rate and oxygen uptake recovery in mountain bike athletes.

Material and methods. The study examined 29 mountain bikers, including members of the Polish National Team. These athletes specialised in cross-country Olympic (XCO) racing. After undergoing a graded stress test on a cycle ergometer, the subjects were divided into two groups: G1, consisting of athletes with higher aerobic capacity (n = 12; VO2max > 60 ml∙kg−1∙min−1), and G2, comprising athletes with lower aerobic capacity (n = 17; VO2max < 55 mL∙kg−1∙min−1). Heart rate and oxygen uptake recovery was measured after the graded stress test in a sitting position.

Results. HRmax values did not differ significantly between the two groups. HR1’, HR2’, and HR4’ values recorded for G1 were statistically significantly lower compared to those achieved by G2. %HR1’, %HR2’, %HR4’, and %HR5’ values were also significantly lower in G1 than in G2. No significant differences were found in oxygen uptake during recovery (VO2-1’, 2’, 3’, 4’, 5’) between the two groups. Significantly lower %VO2max-1’, %VO2max-2’, and %VO2max-5’ values were observed in G1 compared to those in G2. No significant correlations were found between VO2max per kilogram of body mass and the recovery efficiency index in either group. There was, however, a statistically significant correlation between VO2max and the recovery efficiency index (R = 0.52) in the entire group of athletes (n = 29).

Conclusion. The study showed that the work capacity of mountain bike athletes was associated with the rate of heart rate and oxygen uptake recovery.

Abstract

Introduction. So far there have been few studies on the effect of interval training with active recovery aimed at increasing aerobic power on the physical capacity of long-distance runners. Unlike standard interval training, this particular type of interval training does not include passive rest periods but combines high-intensity training with low-intensity recovery periods. The aims of the study were to determine the effect of aerobic power training implemented in the form of interval training with active recovery on the physical capacity of amateur long-distance runners as well as to compare their results against those of a group of runners who trained in a traditional manner and only performed continuous training.

Material and methods. The study involved 12 recreational male long-distance runners, who were randomly divided into two groups, consisting of 6 persons each. Control group C performed continuous training 3 times a week (for 90 minutes, with approximately 65-85% VO2max). Experimental group E participated in one training session similar to the one implemented in group C and additionally performed interval training with active recovery twice a week. The interval training included a 20-minute warm-up and repeated running sprints of maximum intensity lasting 3 minutes (800-1,000 m). Between sprints, there was a 12-minute bout of running with an intensity of approximately 60-70% VO2max. The time of each repetition was measured, and the first one was treated as a benchmark in a given training unit. If the duration of a subsequent repetition was 5% shorter than that of the initial repetition, the subjects underwent a 15-minute cool-down period. A progressive treadmill test was carried out before and after the 7-week training period. The results were analysed using non-parametric statistical tests.

Results. VO2max increased significantly both in group E (p < 0.05; d = 0.86) and C (p < 0.05; d = 0.71), and there was an improvement in effort economy at submaximal intensity. Although the differences were not significant, a much greater change in the post-exercise concentrations of lactate and H+ ions was found in group E.

Conclusions. The study showed that interval training with active recovery increased VO2max in amateur runners with higher initial physical capacity and stimulated adaptation to metabolic acidosis more than continuous training.

Abstract

During single particle analysis of aerosol in Kraków (Poland) we noticed a new component, that is, aggregates of TiO2 particles. These aggregates are from 0.5 to 4 μm and are composed of individual particles whose size typically varies from between 100 and 350 nm. Smaller particles (below 100 nm) also occur. TiO2 particles are relatively abundant in the summer. The size distribution of the particles corresponds to “pigmentary” TiO2, which indicates that they could be derived from paints and building materials. TiO2 particles were not previously identified in aerosol samples in Kraków, and therefore this phenomenon is likely to be related to the common usage of new building materials and paints. A review of the literature suggests that TiO2 particles, especially within the nanosize range, could result in health and environmental impacts; however, evaluation of the actual threat is difficult.

Abstract

Introduction. The aim of the study was to verify the influence of warm-up before a ramp incremental exercise test with linearly increasing loads on the maximal values of physiological variables which determine performance.

Material and methods. Thirteen healthy and physically active male students (age = 23.3 ± 1.5 years, body height = 179.1 ± 8.6 cm and body mass = 79.5 ± 9.1 kg) completed a cross-over comparison of two incremental exercise test interventions – an incremental exercise test with a 15-minute warm-up at an intensity of 60% of the maximal oxygen uptake obtained in the first incremental exercise test and the same test without warm-up.

Results. The peak values of physiological variables were statistically significantly higher for the incremental exercise test with warm-up, the differences between tests being 2.66% for peak power output (p = 0.039, t = 2.312, ES = 0.24), 7.75% for peak oxygen uptake (p = 0.000, t = 5.225, ES = 0.56), 7.72% for peak minute ventilation (p = 0.005, t = 3.346, ES = 0.53) and 1.62% for peak heart rate (p = 0.019, t = 2.690, ES = 0.60).

Conclusions. Warm-up before a ramp incremental exercise test resulted in higher values of maximal oxygen uptake, maximal minute ventilation, maximal heart rate and peak power output.

Abstract

The production of platform carbonates of the Manín Unit (Manín Straits, Central Western Carpathians) belonging to the Podhorie and Manín formations and formed by remains of rudists and benthic foraminifers (Urgonian-type carbonates), was previously assumed to terminate during the Aptian. First, we show that these deposits were primarily formed on the upper slope (Podhorie Formation) and in a fore-reef environment (Manín Formation). Second, biostratigraphic data indicate that the shallow-water production persisted up to the Albian, just as it did in another succession of the Manín Unit. The Podhorie Fm contains colomiellids (Colomiella recta, C. mexicana) and calcareous dinoflagellates (Calcisphaerula innominata) that indicate the Albian age. It also contains planktonic foraminifers (Ticinella roberti, Ticinella cf. primula, Ticinella cf. madecassiana, Ticinella cf. praeticinensis) of the Albian Ticinella primula Zone. The Podhorie Formation passes upwards into peri-reefal facies of the Manín Fm where we designate the Malý Manín Member on the basis of rudists shell fragments and redeposited orbitolinids. Microfacies associations share similarities with the Urgonian-type microfacies from Mediterranean Tethys and allow us to restrict the growth and the demise of the carbonate platform. δ13C and δ18O isotopes change over a broad range of both formations: δ13C is in the range +1.03 to +4.20 ‰ V-PDB and δ18O is in the range −0.14 to −5.55 ‰ V-PDB. Although a close correlation between δ13C and δ18O indicates diagenetic overprint, a long-term increase of δ13C can indicate a gradual increase in the aragonite production and/or increasing effects of oceanic water masses in the course of the Albian, prior to the final platform drowning. Carbonate platform evolution was connected with submarine slumps and debris flows leading to redeposition and accumulation of carbonate lithoclasts and bioclastic debris on the slope. Our study confirms that the growth of carbonate platforms in the Central Western Carpathians was stopped and the platform collapsed during the Albian, in contrast to the westernmost Tethys. A hardground formed during the Late Albian is overlain by Albian - Cenomanian marls of the Butkov Formation with calcisphaerulid limestones characterized by planktonic foraminifers of the Parathalmanninella appenninica Zone and calcareous dinoflagellates of the Innominata Acme Zone.