Cardio-respiratory fitness of young and older active and sedentary men.

Physiological profiles are described for 30 healthy young (20-31 years) and 30 healthy older (50-62 years) men. Half of the individuals in each group reported that during the previous five years they participated frequently in strenuous physical exercises; the other half reported sedentary lifestyles. A treadmill exercise test was used to determine maximal aerobic power (VO2 max). Heart rate and blood pressure were measured during rest, maximal exercise and recovery. The active older men demonstrated significantly lower resting heart rates, lower resting systolic and diastolic blood pressures, higher VO2 max, lower maximal exercise diastolic blood pressure and lower recovery heart rates than the age-matched sedentary men. Compared with the young sedentary men, the older active men had lower resting heart rates and higher VO2 max, walked longer on the treadmill, had lower recovery heart rates and weighed less. Older active men also had higher VO2 max levels than young sedentary men. In summary, physiological profiles of the older active men more closely resembled profiles of active men who were 30 years younger than those of older sedentary men. These results emphasize the range of benefits associated with exercise.     

Differences in blood lipids and apolipoproteins between master athletes, recreational athletes and sedentary men

AIM: Studies related with the role of intensive and moderate training on reducing coronary heart disease (CHD) risks have revealed conflicting RESULTS: Thus, the aim of this study was to clarify the association between long-term physical training with competitive and recreational purposes and blood lipids and apolipoproteins in the middle-aged master athletes, recreational athletes and sedentary controls. METHODS: The association between long-term physical training and serum concentrations of lipids, lipoproteins, and apolipoproteins in the middle-aged men was investigated. Twelve male master athletes (MA), 12 male recreational athletes (RA) (>10 y), and 12 male sedentary controls (CG) participated in the study. Serum concentrations of lipids and lipoproteins were measured by enzymatic methods; apolipoproteins (ApoA1 and ApoB) and serum lipoprotein(a) Lp(a) were measured by immonoprecipitation assays. RESULTS: TC, LDL-C, ApoA1, Lp(a) levels and LDL-C/HDL-C ratio of the 3 groups did not show any significant differences. MA and RA had significantly higher levels of VO2max, HDL-C, ApoA1/ApoB ratio; and lower values of percent body fat, resting heart rate, systolic and diastolic blood pressures, TG, ApoB and TC/HDL-C ratio than CG. We did not find any significant differences between MA and RA in any variables except for BMI and TC/HDL-C ratio. CONCLUSIONS: Habitual physical training favorably altered serum lipid and apolipoprotein profiles. Although there was no statistical significance (except for BMI and TC/HDL-C) between MA and RA, a tendency to reduce the CHD risks was observed almost in all variables in favor of MA.     

Heart size and function of soldiers, athletes, and sedentary men

This study compares the heart sizes and left ventricular masses of soldiers (n = 11) with age- and body size-matched groups of sedentary men (n = 10) and accomplished athletes (n = 11). Echocardiography revealed that active duty soldiers (A) who met minimal fitness standards and pentathletes (P) had greater average left ventricular (LV) end-diastolic volumes (A = 10%, NS; P = 28%, p less than 0.05), stroke volumes (A = 29%, NS; P = 44%, p less than 0.01), and LV masses (A = 22%, NS; P = 76%, p less than 0.01) than sedentary subjects. Athletes had an average LV wall thickness which was 23% (p less than 0.05) greater than that of soldiers and 32% (p less than 0.01) greater than that of sedentary men. The LV wall thickness to radius ratio (h/r) was similar between soldiers and sedentary men, but in athletes the h/r was greater (p less than 0.01) than in the less conditioned subjects. These data suggest that soldiers who meet minimal standards of fitness exhibit cardiac morphometric features consistent with endurance conditioning. However, the soldiers studied were significantly less (p less than 0.001) conditioned than the competitive athletes. These data suggest that improvements in aerobic and cardiac conditioning could be achieved through a greater emphasis on physical training.     

Aerobic and anaerobic capacity of adult and young professional soccer players

While VO_2max has been widely investigated, there is few research on anaerobic capacity (AC) in soccer players. Previous studies reported that AC is age-dependent and that young individuals had lower AC compared with adults. Thus, we wondered whether AC would have proven more useful than VO_2max in differentiating adult soccer players from young players. A total of 37 male athletes from a professional team were recruited and divided into two sub-groups: the adult (AD, n = 20) group, older than 19 years, and the young (YO, n = 17) group, ranged from 16 to 18 years. Each participant underwent an incremental test on a treadmill to assess maximal velocity (V _max), anaerobic threshold (AT) and VO_2max and a supramaximal exercise at a velocity 10 % higher than V _max to measure AC. The AD group reached higher AT and VO_2max with respect to the YO group (55.23 ± 4.65 vs. 51.48 ± 4.73 mL min^?1 kg^?1), whereas no difference was found in parameters related to the AC. In conclusion, young soccer players had the same AC as adult, but they displayed a lower VO_2max. These findings indicated that AC in professional players is fully developed already when they are young while aerobic capacity is still to be developed.     

Complement and immunoglobulin levels in athletes and sedentary controls

Eleven marathon runners (42.7 +/- 2.1 yrs, 54.2 +/- 1.8 ml.kg-1.min-1) and nine sedentary controls (44.2 +/- 1.2 yrs, 33.3 +/- 1.1 ml.kg-1.min-1) were studied during 30 min of rest, a graded maximal treadmill test using the Balke protocol, and 45 min of recovery to determine the effects of training and acute exercise on complement and immunoglobulin levels. Three baseline and five recovery blood samples were obtained in addition to repeated 5-min samples during exercise. Data for the exercise period were analyzed using a multiple regression approach to repeated measures ANOVA to allow comparison between groups on a percent VO2max basis. Groups did not differ during any of the three phases for IgG, IgA, or IgM. Resting levels of complement C3 (0.89 +/- 0.05 vs 1.27 +/- 0.10 g/L, P less than 0.001) and C4 (0.19 +/- 0.02 vs 0.29 +/- 0.03 g/L, P less than 0.001) were significantly lower in athletes than in controls. Exercise complement C3 [F(1,18) = 14.1, P = 0.001] and C4 [F(1,18) = 7.6, P = 0.013], and recovery complement [F(1,18) = 19.4, P less than 0.001] and C4 [F(1,18) = 13.5, P = 0.002] were also lower in the athletes than in sedentary controls. Acute increases during exercise were not associated with changes in catecholamines or cortisol. These data suggest that blood concentrations of C3 and C4, but not IgG, IgA, or IgM, are decreased during rest, graded maximal exercise, and recovery in marathon runners in comparison with sedentary controls.     

LDL particle size in habitual exercisers, lean sedentary men and abdominally obese sedentary men

Habitual exercisers enjoy considerable protection from coronary heart disease (CHD). Often, however, only modest differences in traditional CHD risk factors are apparent between habitual exercisers and their sedentary counterparts. For this reason, there is increasing interest in novel predictors of CHD, such as a preponderance of small, dense low-density lipoprotein (LDL) particles. Polyacrylamide gel electrophoresis was used to separate lipoprotein subfractions in 32 lean exercisers, 36 lean sedentary men and 21 obese sedentary men aged 30 - 45 years. Well-validated equations were used to determine LDL concentration and peak particle diameter. Waist girth was used to identify lean (< 100 cm) and obese (>or= 100 cm) individuals. LDL concentration was lower in lean exercisers than in lean sedentary men (2.64 +/- 0.44 vs. 3.76 +/- 0.79 mmol . l (-1), p < 0.001), suggesting that habitual exercise influences this risk factor. In contrast, there were no significant differences in LDL peak particle diameter between lean exercisers, lean sedentary men and obese sedentary men (27.92 +/- 0.67, 28.09 +/- 0.62 and 27.77 +/- 0.77 nm, respectively). In multiple linear regression analysis, triglyceride concentration was the only significant predictor of LDL PPD. These data suggest that habitual exercise influences LDL concentration but does not influence LDL particle size in men aged 30 - 45 years.     

Aerobic fitness in young Norwegian men: a comparison between 1980 and 2002

The purpose of this study was to compare the maximal oxygen uptake (VO2max) in 18-19-year-old Norwegian men from 1980 to 1985 and 2002. In addition, we investigated the relationship between VO2max and education and smoking habits in the sample from 2002. From 1980 to 1985, VO2max was predicted using the Astrand-Rhyming bicycle test for 183 610 eighteen-year-old Norwegian men (91% of the male Norwegian population in this age group). In 2002, the same test was performed on a representative sample of the same age population (N=1028). VO2max (mL x kg(-1)x min(-1)), decreased by 8%, body weight increased by 7% and body mass index (BMI) increased by 6% over the approximately 20-year period (P<0.01). Results from the 2002 sample revealed that smokers had a lower VO2max than non-smokers and vocational students had a lower VO2max than academic students (P<0.05). The average reduction in VO2max was because of an increased number of men with low or very low VO2max, and a reduced number of men with high VO2max values. This is of particular concern since the prevalence of lifestyle-related diseases is higher in groups with low VO2max.     

Body composition and aerobic capacity in young and middle-aged endurance-trained men

Aging is associated with increased body fat, decreased muscle mass, lower maximal O2 uptake, and lower energy intake. It has been asserted that these changes are caused in part by decreased activity. In order to determine the effects of aging in men who are habitually active, 6 young men (26.8 +/- 1.2 yr) and 6 middle-aged men (52.0 +/- 1.9 yr) who had been running, cycling, and/or rowing for at least 2 yr were studied in a metabolic ward. The men consumed a diet to maintain constant body weight while keeping to their usual exercise schedule and intensity. Both groups had a similar body mass index and muscle mass, but the middle-aged men had a 77% greater fat mass (P = 0.028). Daily energy requirement was 17% lower in the middle-aged men (P = 0.029) although basal metabolic rate was similar in both groups. Aerobic capacity was 15% lower in the middle-aged men per unit body weight (P = 0.048) but not per unit of lean body mass. The young men exercised for an average 12.3 hr.wk-1 and the middle-aged men for 7.5 hr.wk-1 (P = 0.018). For both young and middle-aged men, weekly hours of exercise were negatively correlated with fat mass, and positively correlated with daily energy requirements and maximal O2 uptake. These findings show that in both young and middle-aged men who habitually exercise aerobically at 65 to 80% maximal O2 uptake, the time spent training was associated with body composition, energy requirements, and aerobic capacity.     

Effects of iron repletion on blood volume and performance capacity in young athletes

PURPOSE: The purpose of this study was to find out whether iron repletion leads to an increase in red blood cell volume (RBV) and performance capacity in iron-deficient nonanemic athletes. METHODS: 40 young elite athletes (13-25 yr) with low serum ferritin (< 20 microg.L-1) and normal hemoglobin (males > 13.5 g.dL-1, females > 11.7 g.dL-1) were randomly assigned to 12-wk treatment with either twice a day ferrous iron (equivalent to 2 x 100 mg elemental iron) or with placebo using a double blind method. Before and after treatment, hematological measures and parameters of iron status were determined in venous blood. RBV, blood volume (BV), and plasma volume (PV) were measured by CO rebreathing. For determination of the aerobic and anaerobic capacity (maximal accumulated oxygen deficit, MAOD), the athletes performed an incremental as well as a highly intensive treadmill test. RESULTS: After 12 wk, ferritin levels were within the normal range in the iron-treated group (IG) with a significant (P < 0.001) mean increase by 20 microg.L-1 opposed to a slight nonsignificant decrease in the placebo group (PG). RBV did not change significantly in either group nor did any of the hematological measures. However, only in IG there were significant increases in VO2max and in O2 consumption in the MAOD test. MAOD and maximal capillary lactate concentration remained unchanged in both treatment groups. CONCLUSIONS: The results indicate that in young elite athletes with low serum ferritin and normal hemoglobin concentration iron supplementation leads to an increase in maximal aerobic performance capacity without an augmentation of RBV.     

The impact of patellar tendinopathy on sports and work performance in active athletes

Greater insight into sports and work performance of athletes with patellar tendinopathy (PT) will help establish the severity of this common overuse injury. Primary aim of this study is to investigate the impact of PT on sports and work performance. Seventy seven active athletes with PT (50 males; age 28.1 ± 8.2 years; Victorian Institute of Sports Assessment Patella 56.4 ± 12.3) participated in this survey. Sports performance, work ability and work productivity were assessed using the Oslo Sports Trauma Research Center overuse injury questionnaire, the single-item Work Ability Index and the Quantity and Quality questionnaire, respectively. Reduced sports performance was reported by 55% of the participants; 16% reported reduced work ability and 36% decreased work productivity, with 23% and 58%, respectively, for physically demanding work. This study shows that the impact of PT on sports and work performance is substantial and stresses the importance of developing preventive measures.     

Body composition of healthy sedentary and trained, young and older men and women.

This study examined the effects of age and physical activity on body composition and fat distribution by comparing differences between young and older endurance trained men and women with differences between young and older sedentary people. Although indices of total body adiposity (fat mass, percent body fat) were higher in the older than in the young people in both the trained and the sedentary groups, the magnitude of the difference was markedly less in the trained group (P less than 0.01). The average differences in fat mass between young and old sedentary men and women were 10.1 kg and 12.2 kg, respectively, but only 4.3 kg and 5.5 kg in trained men and women. Skinfold thicknesses were approximately 24% and approximately 47% larger at all sites (triceps, thigh, subscapula, pectoralis, umbilicus, suprailiac) in the older than in the young trained men and women, respectively. Similar differences were found between young and older sedentary people except at central, upper body sites, where the relative differences in skinfold thicknesses between young and older sedentary people were 2- to 6-fold greater than in trained people. Thus, people who exercise regularly appear to accumulate less adipose tissue in upper, central body regions as they get older, potentially reducing the risk for the metabolic disorders associated with upper body obesity.     

COVID-19 pandemic impacts physical activity levels and sedentary time but not sleep quality in young badminton athletes

Purpose

Regular physical activity is a good strategy to maintain the health of athletes, and prevent pain and decreased joint flexibility during the pandemic. On the other hand, higher sedentary time during the pandemic period can have deleterious effects. The objective of this study was to compare physical activity levels, sedentary time, and sleep parameters during the pre-COVID period and the COVID-19 pandemic period in young badminton athletes.

Methods

Fifteen young badminton athletes were evaluated during a pre-COVID period (July 2019) and during the COVID-19 period (July 2020). Sleep parameters, physical activity level, and sedentary time were measured using a tri-axial accelerometer. Participants wore the accelerometer on their dominant wrist for 7 days consecutively. In addition, the average of each sleep parameter [time in bed and total sleep time in hours per day, sleep efficiency (%), wake after sleep onset (WASO, total per day), and sleep latency (minutes per day)] was reported over the 7-day period.

Results

Athletes presented increased sedentary time (pre-COVID?=?7.0?±?1.1 vs.COVID-19?=?8.9?±?1.9 h/day, p?=?0.004, d?=?1.30) and significant decreases in the total PA observed in counts per day (pre-COVID?=?2,967,064.4?±?671,544.1 vs. COVID-19?=?1,868,210.2?±?449,768.4 counts/day, p?=?0.001, d?=?1.99), time in vigorous PA (pre-COVID?=?7.7?±?0.9 vs. COVID-19?=?6.1?±?1.2 h/day, p?=?0.001, d?=?1.56), and time in moderate-to-vigorous PA (pre-COVID?=?8.1?±?0.9 vs. COVID-19?=?6.5?±?1.3 h/day, p?=?0.001, d?=?1.48). There were no significant differences for time in light and moderate PA or in sleep parameters (p?>?0.05).

Conclusion

Young badminton athletes presented increased sedentary time, and decreased total physical activity, time in MVPA, and time in vigorous activities during the COVID-19 pandemic compared to the pre-COVID period, however, there were no significant differences in sleep parameters.

     

Heparin-released plasma lipase activities, lipoprotein and apoprotein levels in young adult cyclists and sedentary men

Serum lipid and lipoprotein levels, apolipoproteins A-I and B, and lipolytic enzyme activities were studied in 14 young male cyclists and in 21 age-matched sedentary controls. While there were no significant differences in serum cholesterol between the two groups, the cyclists showed a significant decrease in serum triglycerides (P less than 0.05) and LDL cholesterol (P less than 0.05) and had significantly higher levels of HDL cholesterol (P less than 0.01) and HDL2 cholesterol (P less than 0.001). Significantly lower serum cholesterol/HDL cholesterol (P less than 0.001) and LDL cholesterol/HDL cholesterol (P less than 0.001) ratios and a significantly higher HDL2 cholesterol/HDL3 cholesterol ratio (P less than 0.001) were observed in the athletes. Serum apolipoprotein B was lower and the Apo B/Apo A-I ratio significantly reduced in the athletes. No significant differences emerged between the two groups in plasma post-heparin lipoprotein lipase activity (LPL) and in hepatic triglyceride lipase activity (HTGL), and there were no correlations between HDL cholesterol and lipolytic enzyme activities. In conclusion, this cross-sectional study may indicate that an aerobic training program such as cycling is associated with an advantageous lipoprotein pattern; some factors other than lipolytic activity may contribute to increase the HDL cholesterol levels in physical training.     

Ultrasound elastography of the patellar tendon in young,asymptomatic sedentary and moderately active individuals

BackgroundThe recent use of ultrasound elastography to study patellar tendon softness has demonstrated increased tendon softness in high-level athletes. We hypothesized that measurable alterations in patellar tendon softness may be present in young asymptomatic subjects engaging in moderate levels of physical activity.MethodsThis was a cross-sectional study. Gray-scale ultrasound and ultrasound elastography of the right and left patellar tendons were performed in young asymptomatic sedentary subjects and moderately active subjects who engaged in at least 30 min of physical activity 4–5 times weekly. The distribution of soft, intermediate and stiff tissue within each tendon was analyzed. Tendon softness was correlated with subject age, gender and level of athletic activity.ResultsSixty patellar tendons in 30 subjects were evaluated (18 males, 12 females, mean age 22.5 years). Seventeen subjects were defined as “active” and 13 as “sedentary.” All tendons had a normal gray-scale sonographic appearance. Tendon softness was significantly higher in active subjects (P = 0.01) and decreased with age (P = 0.04). In sedentary individuals there was no significant correlation between age and tendon softness (P = 0.404). Similarly, gender showed no correlation with tendon softness (P > 0.05).ConclusionsPatellar tendon softness is higher in young subjects and in those engaging in moderate physical activity. This may reflect an adaptation to increased tendon load. Tendon softness in active subjects decreases with age, while it remains at a constant value in sedentary individuals.Level of evidence: Level 3.