Practical Considerations for Assessing Pulmonary Gas Exchange and Ventilation During Flume Swimming Using the MetaSwim Metabolic Cart

Aerobic capacity in swimming, cycling and arm cranking in swimmers aged 11-13 years

BACKGROUND

This study aimed to compare the aerobic capacity in swimming, cycling and arm cranking in swimmers aged 11-13 years.

METHODS

Eleven swimmers (mean age, 12.1 ± 1.0 years) performed three incremental exercise tests. One of the tests was performed under specific conditions (front crawl swimming), and the other two were under non-specific conditions (cycling and arm cranking). Data on the pulmonary gas exchange were recorded using the portable analyser MetaMax 3B (Cortex, Leipzig, Germany). One-way analysis of variance for repeated measures was employed to test the null hypothesis and determine statistically significant differences between the indicators obtained under specific and non-specific testing conditions. Pearson's correlation coefficient was calculated to assess the relationships between the indicators of the pulmonary gas exchange.

RESULTS

The relative peak oxygen uptake (V̇O2peak) value during swimming was 49.3 ± 6.2 mL/kg/min, which was higher than that during arm cranking (39.6 ± 7.3 mL/kg/min; P < 0.01) but lower than that during cycling (54.3 ± 7.8 mL/kg/min; P < 0.01). The peak minute ventilation (V̇Epeak) value during swimming (84.9 ± 12.6 L/min) was higher than that during arm cranking (69.4 ± 18.2 L/min; P < 0.01) but lower than that during cycling (98.4 ± 15.4 L/min; P < 0.01). Strong positive correlations were observed in the absolute and relative V̇O2peak values between swimming and cycling (r = 0.857, P < 0.01; r = 0.657, P < 0.05) and between swimming and arm cranking (r = 0.899, P < 0.01; r = 0.863, P < 0.05). A strong positive correlation was also observed in V̇Epeak values between swimming and arm cranking (r = 0.626, P < 0.05).

CONCLUSION

Swimmers aged 11-13 years showed V̇O2peak and V̇Epeak values during the specific swimming test greater than those during arm cranking but lower than those during cycling. However, aerobic capacity parameters measured during specific swimming conditions correlated with those measured during non-specific arm cranking and cycling conditions.

Enhancing performance: unveiling the physiological impact of submaximal and supramaximal tests on mixed martial arts athletes in the -61 kg and -66 kg weight divisions

This study delves into the intricate details of Mixed Martial Arts (MMA) by examining key variables such as maximal oxygen uptake (VO2 peak), aerobic energy (EAER), anaerobic energy (EAN), and accumulated O2 deficit (DOA). By investigating associations and comparing athletes in the -61 kg bantamweight and -66 kg featherweight weight divisions, we aim to shed light on their physiological characteristics. The sample consisted of 20 male volunteers separated into two paired groups: ten athletes in the category up to 61 kg (age: 27.7 ± 5.9 years old, height: 170.9 ± 3.4 cm, body mass: 72.8 ± 1.4 kg, fat percentage: 9.5% ± 3.0%, professional experience: 7.5 ± 7.1 years) and ten athletes up to 66 kg (age: 27.6 ± 2.9 years old, height: 176.0 ± 5.5 cm, body mass: 77.0 ± 1.5 kg, fat percentage: 7.85% ± 0.3%, professional experience: 5.5 ± 1.5 years). Remarkably, our findings revealed striking similarities between the two weight divisions. Furthermore, we discovered a negative correlation between VO2 peak and the number of MMA fights, indicating a potential impact of professional experience on aerobic capacity (r = -0.65, p < 0.01). Additionally, the number of fights exhibited negative correlations with anaerobic energy (r = -0.53, p < 0.05) and total energy cost (r = -0.54, p < 0.05). These results provide valuable insights for designing training programs in the context of MMA. While training both weight divisions together can be beneficial, it is equally crucial to incorporate specific weight-class-focused training to address each division's unique physical demands and requirements.

Reliability and Validity of a Flume-Based Maximal Oxygen Uptake Swimming Test

A mode-specific swimming protocol to assess maximal aerobic uptake (VO₂max_sw) is vital to accurately evaluate swimming performance. A need exists for reliable and valid swimming protocols that assess VO₂max_sw in a flume environment. The purpose was to assess: (a) reliability and (b) "performance" validity of a VO₂max_sw flume protocol using the 457-m freestyle pool performance swim (PS) test as the criterion. Nineteen males (n = 9) and females (n = 10) (age, 28.5 ± 8.3 years.; height, 174.7 ± 8.2 cm; mass, 72.9 ± 12.5 kg; %body fat, 21.4 ± 5.9) performed two flume VO₂max_sw tests (VO₂max_swA and VO₂max_swB) and one PS test [457 m (469.4 ± 94.7 s)]. For test-retest reliability (Trials A vs. B), moderately strong relationships were established for VO₂max_sw (mL·kg^-1·min^-1)(r= 0.628, p = 0.002), O₂pulse (mL O₂·beat^-1)(r = 0.502, p = 0.014), VEmax (L·min^-1) (r = 0.671, p = 0.001), final test time (sec) (0.608, p = 0.004), and immediate post-test blood lactate (IPE (BLa)) (0.716, p = 0.001). For performance validity, moderately strong relationships (p < 0.05) were found between VO₂max_swA (r =-0.648, p = 0.005), O₂pulse (r= -0.623, p = 0.008), VEmax (r = -0.509 p = 0.037), and 457-m swim times. The swimming flume protocol examined is a reliable and valid assessment of VO₂max_sw., and offers an alternative for military, open water, or those seeking complementary forms of training to improve swimming performance.

Oxygen uptake kinetics and ventilatory and metabolic parameters do not differ between moderate-intensity front crawl and breaststroke swimming

Pulmonary oxygen uptake ( V ̇ O 2 ) kinetics have been well studied during land-based exercise. However, less is known about V ̇ O 2 kinetics during swimming exercise and comparisons between strokes is non-existent. We aimed to characterize and compare the V ̇ O 2 kinetics, ventilatory,e and metabolic response to constant velocity moderate-intensity freely breathing front crawl (FC) and breaststroke (BR) swimming in a swimming flume. These two strokes reflect predominantly upper body versus lower body modes of swimming locomotion, respectively. Eight trained swimmers (4 females, 20 ± 1 years, 1.74 ± 0.06 m; 66.8 ± 6.3 kg) attended 5-6 laboratory-based swimming sessions. The first two trials determined FC and BR V ̇ O 2 max and the ventilatory threshold (VT), respectively, during progressive intensity swimming to the limit of tolerance. Subsequent trials involved counterbalanced FC and BR transitions from prone floating to constant velocity moderate-intensity swimming at 80% of the velocity at VT (vVT), separated by 30-min recovery. Breath-by-breath changes in pulmonary gas exchange and ventilation were measured continuously using a snorkel and aquatic metabolic cart system. The ventilatory and metabolic responses were similar (p > 0.05) between strokes during maximal velocity swimming, however, vVT and maximal velocity were slower (p < 0.05) during BR . During moderate-intensity swimming, V ̇ O 2 kinetics, ventilatory and metabolic parameters were similar (p > 0.05) between strokes. In conclusion, when breathing ad libitum, V ̇ O 2 kinetics during moderate-intensity constant velocity swimming, and ventilatory and metabolic responses during moderate-intensity and maximal velocity swimming, are similar between FC and BR strokes.

Is V̇O2peak a Valid Estimation of V̇O2max in Swimmers with Physical Impairments?

Purpose: Peak and maximal oxygen uptake ([Formula: see text] and [Formula: see text], respectively) are used in assessing aerobic power. For swimmers with physical impairments, it is unclear whether the physiological variables obtained in 200-m and Nx200-m tests are similar. The objective of this study is to assess the validity of [Formula: see text] as an estimator of [Formula: see text] and complementary physiological variables, in particular, carbon dioxide production ([Formula: see text]), respiratory exchange ratio (RER), minute-ventilation ([Formula: see text] and absolute (HR) and relative (%HRmax) heart rates-which were obtained in a time trial test (200-m) and an incremental intermittent test (Nx200-m) performed by swimmers with physical impairments. Methods: Eleven well-trained swimmers with physical impairments performed 200-m all-out and Nx200-m from low to all-out (controlled by a visual pacer), both with a respiratory valve system and a portable gas analyzer. Results: A paired Student's t-test showed no statistical difference (p > .05) for all comparisons. The intraclass correlation coefficient (ICC) was 0.97 and 0.98 for [Formula: see text] in l/min and ml/kg/min, respectively; ICC = 0.75 to 0.9 for [Formula: see text] (l/min and ml/kg/min),[Formula: see text] (in l/min) and HR (beats/min); ICC = 0.5 and 0.75 for %HRmax; and ICC < 0.5 for RER. Passing-Bablok regression showed that the dispersions were acceptable, considering the proportionality, except for HR and %HRmax. Bland-Altman method showed a high level of agreement for all variables. Conclusions: The [Formula: see text] and [Formula: see text], as well as the physiological variables [Formula: see text] and HR obtained, respectively, by 200-m and Nx200-m tests in swimmers with physical impairment were not different.