Regular soccer training improves pulmonary diffusion capacity in 6 to 10 year old boys.

BACKGROUND: Soccer is one of the most attractive sports around the globe for children and adolescents, and the benefits of soccer training are often shown. Due to the intermittent character of soccer with random changes between high-intensity activity and low-intensity play, athletes' aerobic (respiratory) capacity is specifically stimulated. However, little is known about the effects of regular soccer practice on pulmonary diffusion capacity (TL) in young players, even though it is the most popular sport in the world. OBJECTIVES: To analyze the effects of 28 weeks of regular soccer training versus a non-activity control period on the TL, the alveolar-capillary membrane diffusion capacity (DM) as well as the capillary blood volume (Vc) in healthy prepubertal boys aged 6 to 10 years. METHODS: For this purpose, boys were randomly assigned to a soccer training group (SG, n = 40) or a control group (CG, n = 40). Pre and post-intervention, all participants performed an all-out graded bicycle ergometer test to measure maximal oxygen uptake (VO2max) and maximal aerobic power (MAP). A respiratory maneuver was performed at rest and just at the end of the test to measure the TL for carbon monoxide (TLCO) and nitric oxide (TLNO), DM, as well as Vc. RESULTS: There were no significant baseline between-group differences for any of the assessed parameters (p > 0.05). Significant group-by-time interactions were found for most pulmonary parameters measured at rest (p < 0.05), with effect size (ES) values ranging from small-to-large (0.2 < ES < 4.0), except for VA (p = 0.3, ES = 0.006). Post-hoc tests indicated significant DM (p < 0.05; 0.2 < ES < 4.0), TLNO (p < 0.01; 0.22 < ES < 4.0), TLCO (p < 0,01; 0.24 < ES < 4.0) and Vc (p = 0.01; 0.404 < ES < 0.6) improvements for SG but not CG. Significant group-by-time effects were identified for HRmax and VO2max (p < 0.001; ES = 0.5 and p = 0.005; ES = 0.23 respectively). The post-hoc analyses indicated a significant decrease in HRmax and a significant increase in VO2max in the SG (p < 0.001; ES = 0.5 and p = 0.005, ES = 0.23, respectively) but not in CG. Values for TLCO increased by almost 20%; Vc of 14% DM of 8% and VA of 10% at the end of maximal exercise in SG. Furthermore, the percentage improvement was less notable in the control group (7.5% for TLCO; 2% for Vc; 5% for DM and 4% for VA). CONCLUSION: Regular soccer training significantly improves pulmonary vascular function and increases DM and Vc after exercise in prepubertal boys. The observed adaptations are most likely due to better recruitment of additional pulmonary capillary function. However, the stepwise linear regression analyses indicated that increases in pulmonary vascular function were not related to improvements in VO2max and MAP.

Effects of Endurance Training Intensity on Pulmonary Diffusing Capacity at Rest and after Maximal Aerobic Exercise in Young Athletes.

This study compared the effects of varying aerobic training programs on pulmonary diffusing capacity (TLCO), pulmonary diffusing capacity for nitric oxide (TLNO), lung capillary blood volume (Vc) and alveolar-capillary membrane diffusing capacity (DM) of gases at rest and just after maximal exercise in young athletes. Sixteen healthy young runners (16-18 years) were randomly assigned to an intense endurance training program (IET, n = 8) or to a moderate endurance training program (MET, n = 8). The training volume was similar in IET and MET but with different work intensities, and each lasted for 8 weeks. Participants performed a maximal graded cycle bicycle ergometer test to measure maximal oxygen consumption (VO2max) and maximal aerobic power (MAP) before and after the training programs. Moreover, TLCO, TLNO and Vc were measured during a single breath maneuver. After eight weeks of training, all pulmonary parameters with the exception of alveolar volume (VA) and inspiratory volume (VI) (0.104 < p < 0889; 0.001 < ES < 0.091), measured at rest and at the end of maximal exercise, showed significant group × time interactions (p < 0.05, 0.2 < ES < 4.0). Post hoc analyses revealed significant pre-to-post decreases for maximal heart rates (p < 0.0001, ES = 3.1) and improvements for VO2max (p = 0.006, ES = 2.22) in the IET group. Moreover, post hoc analyses revealed significant pre-to-post improvements in the IET for DM, TLNO, TLCO and Vc (0.001 < p < 0.0022; 2.68 < ES < 6.45). In addition, there were increases in Vc at rest, VO2max, TLNO and DM in the IET but not in the MET participants after eight weeks of training with varying exercise intensities. Our findings suggest that the intensity of training may represent the most important factor in increasing pulmonary vascular function in young athletes.

Pulmonary diffusing capacity measured by NO/CO transfer in Tunisian boys.

BACKGROUND: The diffusing capacity, which measures gas-exchange, uses reference values based on data from American or European studies. There are currently no reference values of pulmonary diffusing capacity (TL) and its components, such as the conductance of the membrane (Dm) and capillary lung volume (Vc) for healthy North African children. OBJECTIVES: We determined the prediction equations-reference values for TL, Dm, Vc and the alveolar volume (VA) in healthy Tunisian boys. METHODS: Values of Vc, Dm, TL, and VA were measured by the NO/CO transfer method, using a single breath maneuver in 118 Tunisian boys (8-14 years old) at rest. We performed linear regression analysis of the pulmonary parameters and independent variables, such as height, weight, and age. RESULTS: The reference equations for pulmonary diffusing capacity for carbon monoxide (TLCO ) was 0.201 × weight (kg) + 8.979; for TLNO was 0.76 × height (cm)-24.383; for Dm was 0.388 × height (cm)- 12.555 and for VA was 0.34 × height (cm)-3.951. Vc increased significantly with weight (P < .05) but not with age (P > .05). CONCLUSIONS: References norms for TLCO and TL for nitric oxide and its components in young Tunisian boys are similar to data from other countries. The prediction equations we developed can be extended to clinical practice in Tunisia and can be considered for use in neighboring North African countries.

Membrane conductance in trained and untrained subjects using either steady state or single breath measurements of NO transfer.

The aim of this work was to define the relationship between membrane conductance for NO (Dm) and physical activity by using either the steady state NO transfer (T(LNO)SS) or the single breath method (T(LNO)SB), making the hypothesis that NO transfer is only limited by the membrane. Alterations in T(LNO)SS with lung volume during tidal ventilation were measured in six subjects at rest and during steady exercise at 30, 60, and 80% of maximal aerobic power (MAP). A fast responding chemoluminescent NO analyser was used. Two calculation methods were used by sampling NO: (1) at mid-tidal volume, (2) in the middle of the alveolar plateau. T(LNO)SB at rest and maximal oxygen consumption (V(.-)O(2)max) were also measured in 18 other subjects. At rest T(LNO)SS with method 2 was 192% of the value given by method 1. T(LNO)SS with method 1 increased by 50% with 80% MAP as it did not change with method 2. Method 2 seemed inaccurate. T(LNO)SB at rest, which is closely related to Dm, was correlated to age and V(.-)O(2)max, T(LNO)SB=182-1.2 age+24.3 V(.-)O(2) max(l min(-1)) (p<0.01, r(2)=0.72). The T(LNO)SS and T(LNO)SB versus lung volume relationships suggest an influence of the breathing pattern on Dm. Dm can be estimated either by these two NO transfer methods, however the use of the T(LNO)SS method is highly sensitive to the alveolar sampling level. Dm increase during exercise is a function of MAP. Dm at rest decreases with age as it increases with MAP.

Effects of a Basketball Activity on Lung Capillary Blood Volume and Membrane Diffusing Capacity, Measured by NO/CO Transfer in Children.

In both children and adults, acute exercise increases lung capillary blood volume (Vc) and membrane factor (DmCO). We sought to determine whether basketball training affected this adaptation to exercise in children. The purpose of this study was to determine the effects of two years sport activity on the components of pulmonary gas transfer in children. Over a 2-yr period, we retested 60 nine year old boys who were initially separated in two groups: 30 basketball players (P) (9.0 ± 1.0 yrs; 35.0 ± 5.2 kg; 1.43 ± 0.05 m), and matched non players controls (C) (8.9 ± 1.0 yrs; 35.0 ± 6.0 kg; 1.44 ± 0.06 m) who did not perform any extracurricular activity, Vc and DmCO were measured by the NO/CO transfer method at rest and during sub-maximal exercise. Maximal aerobic power and peak power output was 12% higher in the trained group compared to matched controls (p < 0.05). Nitric oxide lung transfer (TLNO) per unit lung volume and thus, DmCO per unit of lung volume (VA) were higher at rest and during exercise in the group which had undergone regular basketball activity compared to matched controls (p < 0.05). Neither lung capillary blood volume nor total lung transfer for carbon monoxide (TLCO) were significantly different between groups. These results suggest that active sport can alter the properties of the lung alveolo-capillary membrane by improving alveolar membrane conductance in children. Key PointsTrained children had greater DmCO/VA and DmCO/Vc ratios compared with control children during exercise.The mechanisms by which basketball playing children were thought to improve lung diffusion are speculative.Further work will be required to determine the kinetics of the alteration in Dm when children switch from non players to players status or vice-versa.