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Jussi Kosola, Markku Ahotupa, Heikki Kyröläinen, Matti Santtila, and Tommi Vasankari

Purpose:

We hypothesized that lower androgen status together with poor physical fitness associates with atherogenic lipid profile and oxidative stress.

Methods:

Volunteered young men (N = 846, mean age 25.1 ± 4.6 years) were categorized into unfit, average fit, and fit groups according to tertiles of maximal oxygen uptake, series of muscle endurance tests, and maximal upper and lower body strength. Furthermore, concentrations of serum testosterone (TT) and free testosterone (FT) were determined to divide participants into lower and higher testosterone (loTT, hiTT) and free testosterone (loFT, hiFT) subgroups, using medians as cut-off points. The participants were divided into subgroups according to Fitness × Testosterone (Unfit/Average Fit/Fit × Low/High TT/FT), and the concentrations of serum lipids and ox-LDL were measured. Results: The loTT/unfit cardiorespiratory subgroup had 29% higher concentration of ox-LDL compared with the loTT/fit cardiorespiratory subgroup (p = .044). The loTT / unfit cardiorespiratory subgroup had a significantly higher ratio of ox-LDL/HDL-cholesterol compared with the other five TT subgroups (p < .05, in all). While ox-LDL showed a gradual form of decrease from unfit to fit in loTT cardiorespiratory subgroups, no differences were seen in muscular fitness or maximal strength (upper and lower body) subgroups.

Conclusions:

Young men with poor cardiorespiratory fitness together with lower levels of TT have higher concentrations of ox-LDL. Good cardiorespiratory fitness combined with lower androgen levels is not related to atherogenic lipid profile. The combination of poor muscular fitness, or maximal muscle strength, and lower TT levels does not cause atherogenic lipid profile.

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Jani P. Vaara, Heikki Kyröläinen, Mikael Fogelholm, Matti Santtila, Arja Häkkinen, Keijo Häkkinen, and Tommi Vasankari

Background:

The aim was to study the relationships between different domains of physical activity and cardiovascular risk factors and physical fitness.

Methods:

781 young men participated. Self-reported leisure-time (LTPA), commuting (CPA) and occupational (OPA) activity were determined. Blood pressure, s-HDL-cholesterol, s-triglycerides and s-LDL-cholesterol, and glucose were measured. The continuous cardiovascular disease (CVD) risk factor score was calculated from the z-score mean of each cardiovascular risk factor. The cutpoint was defined as 1 standard deviation above the mean. Cardiorespiratory and muscular fitness were measured.

Results:

The likelihood of CVD risk factor score was higher in moderate [OR 1.99 (95% CI 1.21–3.28)] and low [1.87 (1.16–3.02)] CPA groups compared with the high group, whereas neither low nor moderate LTPA or OPA groups showed similar associations after adjustments. Low OPA combined either with low LTPA [2.01 (1.08–3.74)] or low CPA [1.90 (1.05–3.44)] had a higher likelihood for CVD risk factor compared with combined moderate-high categories after adjustments. LTPA was positively associated with all physical fitness parameters, CPA with cardiorespiratory fitness and muscular endurance, and OPA with grip strength.

Conclusion:

The results emphasize the beneficial role of CPA regarding CVD risk factor score and stress the avoidance of low physical activity in its different domains.

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Ritva S. Taipale, Jussi Mikkola, Ari T. Nummela, Juha Sorvisto, Kai Nyman, Heikki Kyröläinen, and Keijo Häkkinen

Purpose:

To examine acute responses of force production and oxygen uptake to combined strength (S) and endurance-running (E) loading sessions in which the order of exercises is reversed (ES vs SE).

Methods:

This crossover study design included recreationally endurance-trained men and women (age 21−45 y; n = 12 men, 10 women) who performed ES and SE loadings. Force production of the lower extremities including countermovement-jump height (CMJ) and maximal isometric strength (MVC) was measured pre-, mid-, and post-ES and -SE, and ground-reaction forces, ground-reaction times, and running economy were measured during E.

Results:

A significant decrease in CMJ was observed after combined ES and SE in men (4.5% ± 7.0% and 6.6% ± 7.7%, respectively) but not in women (0.2% ± 8.5% and 1.4% ± 7.3% in ES and SE). MVC decreased significantly in both men (20.7% ± 6.1% ES and 19.3% ± 9.4% SE) and women (12.4% ± 9.3% ES and 11.6% ± 12.0% SE). Stride length decreased significantly in ES and SE men, but not in women. No changes were observed in ground-reaction times during running in men or women. Performing S before E caused greater (P < .01) oxygen uptake during running in both men and women than if E was performed before S, although heart rate and blood lactate were similar between ES and SE.

Conclusions:

Performing S before E increased oxygen uptake during E, which is explained, in part, by a decrease in MVC in both men and women, decreased CMJ and stride length in men, and/or an increase in postexercise oxygen consumption.

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Jean-Benoît Morin, Georges Dalleau, Heikki Kyröläinen, Thibault Jeannin, and Alain Belli

The spring-mass model, representing a runner as a point mass supported by a single linear leg spring, has been a widely used concept in studies on running and bouncing mechanics. However, the measurement of leg and vertical stiffness has previously required force platforms and high-speed kinematic measurement systems that are costly and difficult to handle in field conditions. We propose a new “sine-wave” method for measuring stiffness during running. Based on the modeling of the force-time curve by a sine function, this method allows leg and vertical stiffness to be estimated from just a few simple mechanical parameters: body mass, forward velocity, leg length, flight time, and contact time. We compared this method to force-platform-derived stiffness measurements for treadmill dynamometer and overground running conditions, at velocities ranging from 3.33 m·s–1 to maximal running velocity in both recreational and highly trained runners. Stiffness values calculated with the proposed method ranged from 0.67% to 6.93% less than the force platform method, and thus were judged to be acceptable. Furthermore, significant linear regressions (p < 0.01) close to the identity line were obtained between force platform and sine-wave model values of stiffness. Given the limits inherent in the use of the spring-mass model, it was concluded that this sine-wave method allows leg and stiffness estimates in running on the basis of a few mechanical parameters, and could be useful in further field measurements.

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Johanna K. Ihalainen, Oona Kettunen, Kerry McGawley, Guro Strøm Solli, Anthony C. Hackney, Antti A. Mero, and Heikki Kyröläinen

Purpose: To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), and amenorrheic (AME) and eumenorrheic (EUM) ATH. Correlations to injury, illness, and performance were also examined. Methods: Altogether 13 ATH and 8 CON completed the Low Energy Availability in Females Questionnaire. Anthropometric, energy intake, and peak oxygen uptake assessments were made at 4 time points throughout the year: at baseline post competition season, post general preparation, post specific preparation, and post competition season the following year. Logs of physical activity, menstrual cycle, illness, and injury were kept by all participants. Performance was defined using the highest International Association of Athletics Federations points prior to and after the study. Results: ATH had significantly lower body mass (P < .008), fat percentage (P < .001), and body mass index (P < .027) compared with CON, while energy availability did not differ between ATH and CON. The Low Energy Availability in Females Questionnaire score was higher in ATH than in CON (P < .028), and 8 ATH (vs zero CON) were AME. The AME had significantly more injury days (P < .041) and ran less (P < .046) than EUM, while total annual running distance was positively related to changes in performance in ATH (r < .62, P < .043, n < 11). Conclusions: More than half of this group of runners was AME, and they were injured more and ran less than their EUM counterparts. Furthermore, only the EUM runners increased their performance over the course of the year.