Subject(s)
COVID-19 , Humans , Athletes , Magnetic Resonance Imaging, Cine , Magnetic Resonance ImagingABSTRACT
PURPOSE: To examine the effect of dryland training during an 11-week lockdown period due to COVID-19 on swimming performance. METHODS: Twelve competitive swimmers performed 50- and 300-m maximum-effort tests in their preferred stroke and 200-, 400-, and four 50-m front crawl sprints (4 × 50 m) before and after the lockdown period. Critical speed as an index of aerobic endurance was calculated using (1) 50-, 300-, and (2) 200-, 400-m tests. Blood lactate concentration was measured after the 400- and 4 × 50-m tests. To evaluate strength-related abilities, the dryland tests included handgrip and shoulder isometric strength. Tethered swimming force was measured during a 10-second sprint. During the lockdown period, dryland training was applied, and the session rating of perceived exertion training (sRPE) load was recorded daily. RESULTS: sRPE training load during the lockdown was decreased by 78% (16%), and critical speed was reduced 4.7% to 4.9% compared to prelockdown period (P < .05). Performance time in 200, 300, and 400 m deteriorated 2.6% to 3.9% (P < .05), while it remained unaltered in 4 × 50- and 50-m tests (P > .05). Tethered force increased 9% (10%) (P < .01), but handgrip and shoulder isometric force remained unaltered (P > .05). Blood lactate concentration decreased 19% (21%) after the 400-m test and was unchanged following the 4 × 50-m tests (P > .05). CONCLUSIONS: Performance deterioration in the 200, 300, and 400 m indicates reduced aerobic fitness and impaired technical ability, while strength and repeated-sprint ability were maintained. When a long abstention from swimming training is forced, dryland training may facilitate preservation in short-distance but not middle-distance swimming performance.
Subject(s)
Athletic Performance , COVID-19 , COVID-19/prevention & control , Communicable Disease Control , Hand Strength , Humans , Lactic Acid , SwimmingABSTRACT
BACKGROUND: This study examined the effects of a five-month lockdown due to COVID-19 pandemic on physical fitness parameters in urban adolescent male and female students. METHODS: Two hundred and ninety-three male and female students (age: 15.8 ± 0.3 years) who attended the fourth grade of the same high school during the years 2016-2017 (first control group), 2018-2019 (second control group) and 2020-2021 (lockdown group) took part in the present study. RESULTS: The percentage of overweight and obese students, according to body mass index, increased in males from 16.0% (2016-2017) and 14.6% (2018-2019), to 36.7% in 2020-2021 (p < 0.01), and in females from 8.6% (2016-2017) and 7.0% (2016-2017), to 25.6% in 2020-2021 (p < 0.01). Lower body fitness, as assessed by jumping, sprinting and agility tests, was impaired for both males and females after the lockdown compared with the 2016-2017 and 2018-2019 cohorts (vertical jumps: 10.4-15.1%; p < 0.01; d = 0.58-1.01, 30 m sprint: 3.7-4.9%; p < 0.01; d = 0.62-0.74; 505 agility test: from 6.1% to 9.4%; p < 0.01; d = 0.80-1.04). However, flexibility and performance in upper-body fitness tests (handgrip maximum isometric strength and medicine ball throws with different loads) was significantly reduced only in males after the lockdown (p < 0.05 to 0.01). CONCLUSIONS: These results suggest that a five-month lockdown negative influenced the physical fitness of adolescent students. Notably, greater reductions were observed in upper body strength, power and flexibility in males than in females. These results highlight the need to maintain strength, power and body mass during long periods of inactivity in adolescent populations.