Assessment of post-competition peak blood lactate in male and female master swimmers aged 40–79 years and its relationship with swimming performance

The main purpose of this study was to measure the postcompetition blood lactate concentration ([La]b) in master swimmers of both sexes aged between 40 and 79 years in order to relate it to age and swimming performance. One hundred and eight swimmers participating in the World Master Championships were assessed for [La]b and the average rate of lactate accumulation (La’;mmol l-1 s-1) was calculated. In addition, 77 of them were also tested for anthropometric measures. When the subjects were divided into 10-year age groups, males exhibited higher [La]b than women (factorial ANOVA, P < 0.01) and a steeper decline with ageing than female subjects. Overall, mean values (SD) of [La]b were 10.8 (2.8), 10.3 (2.0), 10.3 (1.9), 8.9 (3.2) mmol l-1 in women, and 14.2 (2.5), 12.4 (2.5), 11.0 (1.6), 8.2 (2.0) mmol l-1 in men for, respectively, 40–49, 50–59, 60–69, 70–79 years’ age groups. When, however, [La]b values were normalised for a ‘‘speed index’’, which takes into account swimming speed as a percentage of world record, these sex-related differences, although still present, were considerably attenuated. Furthermore, the differences in La’ between males and females were larger in the 40–49 age group (0.34 vs 0.20 mmol l-1 s-1 for 50-m distance) than in the 70–79 age group (0.12 vs 0.14 mmol l-1 s-1 for 50-m distance). Different physiological factors, supported by the considered anthropometric measurements, are suggested to explain the results

Estimation of body composition in competitive swimmers by means of three different techniques

Up to now controversial reports have been published in regard to the beneficial effects of swimming, a non-weight-bearing activity, on bone mass (BM). Therefore, the aim of this study was to investigate the effects of competitive swimming practice on the bone mineral density (BMD) and bone mineral content (BMC) as well as on the different factors of body composition. For this purpose, competitive swimmers (16 males and 16 females) were selected as subjects in order to investigate the influence of swimming on the three main factors of body composition (BMC, lean body mass [LBM] and body fat [BF]) of the human body. The latter were estimated using three different approaches: the skinfold, the dual energy x-ray absorptiometry (DEXA) and the whole body potassium (K-40) methods. Since BM and LBM are also related, the possible correlations between shoulder strength (extensions and flexion movements) and performance with BMD, BMC, LBM and BF were also investigated. Our results showed that BMD was not affected by swimming exercise since z (%) values were similar between swimmers and their respective age-matched controls. Swimmers also showed lower BF and increased LBM in the region of upper extremities (arms and trunk) as compared to their lower extremities (legs), a finding which is typical for the sport they are trained for. Also, comparison between sexes showed that males had a more central distribution of fat when compared to females, in which BF was built up in the region of legs. Furthermore, shoulder strength and performance were significantly related (p &lt; 0.05) to age, BMC, and LBM while performance was also significantly related (p &lt; 0.05) to all the other BM indices. So, mineralization of the bone is important for shoulder muscular strength which is subsequently related to performance. We used the DEXA because it enabled the direct estimation of the three factors of body composition (BM, BF and LBM)

Adherence to CPAP therapy improves quality of life and reduces symptoms among obstructive sleep apnea syndrome patients

Purpose: The aim of the study was to asses quality of life and symptoms of obstructive sleep apnea syndrome (OSAS) patients after adhering to 6 months of continuous positive airway pressure (CPAP) treatment. Methods: A group of 50 patients (41 men and 9 women) were diagnosed by polysomnography and treated with CPAP therapy for 6 months. Their symptoms and healthrelated quality of life were assessed by administering a validated and translated version of the sleep apnea quality of life index (SAQLI). Sleepiness was measured using the Epworth Sleepiness Scale (ESS) and through electronic monitoring of CPAP usage per night of sleep. Results Mean CPAP usage was 4.5±0.5 h per night. Comparisons between quality of life indexes before and after CPAP treatment showed an improvement in the total SAQLI score (3.8±0.9 vs. 5.8±0.8 after CPAP, p&lt;0.01), in daily functioning (4.2±1.4 vs. 6.0±0.9, p&lt;0.01), social interactions (4.8±1.3 vs.6.3±0.7, p&lt;0.01), emotional functioning (4.4±1.4 vs. 5.7±1.0, p&lt;0.01), symptoms (1.6±0.8 vs. 5.8±1.2, p&lt;0.01), and in the ESS (13.7±6.5 vs. 3.9±3.8, p&lt;0.01). Regarding the patients&apos; symptoms, improvement was noticed for &quot;sleepiness while watching a spectacle&quot; (96%), &quot;reading&quot; (95%), &quot;carrying on a conversation&quot;(95%), &quot;driving&quot; (92.9%), &quot;restless sleep&quot; (87.8%), and &quot;urinating more than once per night&quot; (84.8%). Smaller improvements were observed for the reported &quot;dry mouth-throat upon awakening&quot; (36.1%),&quot;excessive fatigue&quot;(54.5%), and &quot;decreased energy&quot; (55.3%). Conclusion We conclude that OSAS patients who adhere to nighttime CPAP therapy show significant improvement of their quality of life, daytime sleepiness, and other symptoms after 6 months of treatment with CPAP. © Springer-Verlag 2011

The changes in age of peak swim speed for elite male and female Swiss freestyle swimmers between 1994 and 2012

Abstract This study determined the age and its changes across years of peak swimming performance from 50 to 1,500 m freestyle. Data of 70,059 Swiss freestyle swimmers (33,725 women and 36,334 men) aged 10-40 years and competing from 50 to 1,500 m were analysed. The association between age and swimming speed of the annual ten fastest swimmers was investigated using single and multi-level hierarchical regression analyses. For women, age of peak swimming speed increased in 50 m from 18.9 (s = 2.3) to 20.4 (s = 4.2) years but decreased in 1,500 m from 25.0 (s = 13.1) (1996) to 18.1 (s = 3.7) years. For 100-800 m, age remained at 19.1 (s = 1.1), 19.3 (s = 1.1), 18.7 (s = 1.5) and 18.5 (s = 1.3) years, respectively. For men, age of peak swimming speed decreased in 50 m from 23.0 (s = 4.0) to 23.0 (s = 3.5) but remained for 100-1,500 m at 22.5 (s = 1.4), 21.4 (s = 0.9), 20.3 (s = 0.9), 20.3 (s = 0.9) and 20.3 (s = 1.1) years, respectively. Age was positively associated with swimming speed for 50-800 m, but negatively for 1,500 m. In conclusion, the age of peak swimming speed was younger in women compared to men for 50-800 m freestyle. For women, age of peak swimming speed increased in 50 m but decreased in 1,500 m freestyle across years. For men, age of peak swimming speed decreased in 50 m freestyle