Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial.

In this double-blind, randomised, controlled trial, we investigated the effects of vitamin C and E supplementation on endurance training adaptations in humans. Fifty-four young men and women were randomly allocated to receive either 1000 mg of vitamin C and 235 mg of vitamin E or a placebo daily for 11 weeks. During supplementation, the participants completed an endurance training programme consisting of three to four sessions per week (primarily of running), divided into high-intensity interval sessions [4-6 × 4-6 min; >90% of maximal heart rate (HRmax)] and steady state continuous sessions (30-60 min; 70-90% of HRmax). Maximal oxygen uptake (VO2 max ), submaximal running and a 20 m shuttle run test were assessed and blood samples and muscle biopsies were collected, before and after the intervention. Participants in the vitamin C and E group increased their VO2 max (mean ± s.d.: 8 ± 5%) and performance in the 20 m shuttle test (10 ± 11%) to the same degree as those in the placebo group (mean ± s.d.: 8 ± 5% and 14 ± 17%, respectively). However, the mitochondrial marker cytochrome c oxidase subunit IV (COX4) and cytosolic peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC-1α) increased in the m. vastus lateralis in the placebo group by 59 ± 97% and 19 ± 51%, respectively, but not in the vitamin C and E group (COX4: -13 ± 54%; PGC-1α: -13 ± 29%; P ≤ 0.03, between groups). Furthermore, mRNA levels of CDC42 and mitogen-activated protein kinase 1 (MAPK1) in the trained muscle were lower in the vitamin C and E group than in the placebo group (P ≤ 0.05). Daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training. However, no clear interactions were detected for improvements in VO2 max and running performance. Consequently, vitamin C and E supplementation hampered cellular adaptations in the exercised muscles, and although this did not translate to the performance tests applied in this study, we advocate caution when considering antioxidant supplementation combined with endurance exercise.

Intelligence-based doping control planning improves testing effectiveness: Perspectives from a national anti-doping organisation.

Anti-doping organisations are mandated to provide a comprehensive anti-doping programme, which aims to detect, deter and prevent doping in sport. Direct detection of prohibited substances and methods by collection of biological samples from athletes makes up about half of the global anti-doping budgets but has in the last decade been under critical scrutiny for its lack of efficiency. To ensure optimum detection and deterrence of testing and prevention efforts, a better understanding of doping practices and comparison of different doping test strategies are needed. This study evaluates 17 years of doping test statistics and Anti-Doping Rule Violations (ADRVs) from the perspectives of a national anti-doping organisation. A total of 48 709 samples (2865 ± 220 annually) were collected by Anti-Doping Norway in the period 2003-2019, which resulted in total 216 ADRVs (12.7 ± 3.7 annually), providing an average sample-to-ADRV rate of 0.44% when including urine, blood and ABP samples. Most athletes who committed ADRVs were men participating in ball and team or strength sports at a national or recreational level. Few ADRVs were recorded among elite athletes and in most high-risk sports, despite these groups being subjected to the highest number of doping tests. The number of annual ADRVs did not correlate with the corresponding number of collected doping samples. However, systematic use of intelligence in the test planning process was associated with an increase in ADRVs. Anti-doping organisations would benefit from improving their target testing capability and to take an intelligence-led approach in planning doping tests.

Acute effect of whole-body vibration on power, one-repetition maximum, and muscle activation in power lifters.

The purpose of this study was to investigate the acute effect of whole-body vibration with a frequency of 50 Hz (WBV(50Hz)) on peak power in squat jump (SJ), 1 repetition maximum (1RM) in parallel squat, and electromyography (EMG) activity and compare them with no-vibration conditions in power lifters. Twelve national level male power lifters (age 24 ± 5 years, body mass 110 ± 24 kg, height 179 ± 7 cm) tested peak power in SJ and 1RM in parallel squat while they were randomly exposed to WBV(50Hz) or to no vibration. These tests were performed in a Smith Machine. Peak power output was higher while performed with a WBV(50Hz) compared with the no-WBV condition (p < 0.05). This increase in power output was accompanied by higher EMG starting values and EMG peak values of the investigated thigh muscles during WBV(50Hz) (p < 0.05). There was no difference between adding WBV(50Hz) and no-vibration conditions in 1RM parallel squat. In conclusion, the results of this study suggest that the application of WBV(50Hz) acutely increases peak power output during SJ in well strength trained individuals such as power lifters. This increase in power was accompanied by an increased EMG activity in the quadriceps muscles. However, in 1RM parallel squat, there was no difference between WBV50Hz and no-vibration conditions. Therefore, adding WBV(50Hz) has no acute additive effect on 1RM parallel squat in power lifters and, based on the present findings, may thus not be recommended in the training to improve 1RM in power lifters. However, WBV(50Hz) seems to have an acute additive effect on peak power output and may be used in well strength trained individuals for whom a high power output is important for performance.

Ten years of collecting hematological athlete biological passport samples-perspectives from a National Anti-doping Organization.

The hematological module of the Athlete Biological Passport (ABP) aims to reveal blood doping indirectly by looking at selected biomarkers of doping over time. For Anti-Doping Organizations (ADOs), the ABP is a vital tool in the fight against doping in sports through improved target testing and analysis, investigations, deterrence, and as indirect evidence for use of prohibited methods or substances. The physiological characteristics of sport disciplines is an important risk factor in the overall risk assessment and when implementing the hematological module. Sharing of experiences with implementing the hematological ABP between ADOs is key to further strengthen and extend its use. In this study, we present 10 years of experience with the hematological ABP program from the perspectives of a National ADO with special attention to sport disciplines' physiological characteristics as a potential risk factor for blood doping. Not surprisingly, most samples were collected in sport disciplines where the aerobic capacity is vital for performance. The study highlights strengths in Anti-Doping Norway's testing program but also areas that could be improved. For example, it was shown that samples were collected both in and out of season in a subset of the data material that included three popular sports in Norway (Cross-Country Skiing, Nordic Combined, and Biathlon), however, from the total data material it was clear that athletes were more likely to be tested out of competition and on certain days of the week and times of the day. The use of doping control officers with a flexible time schedule and testing outside an athlete's 60 min time-slot could help with a more even distribution during the week and day, and thus reduce the predictability of testing. In addition to promoting a discussion on testing strategies, the study can be used as a starting point for other ADOs on how to examine their own testing program.

Effects of vitamin C and E supplementation on endogenous antioxidant systems and heat shock proteins in response to endurance training.

Reactive oxygen and nitrogen species are important signal molecules for adaptations to training. Due to the antioxidant properties of vitamin C and E, supplementation has been shown to blunt adaptations to endurance training. In this study, we investigated the effects of vitamin C and E supplementation and endurance training on adaptations in endogenous antioxidants and heat shock proteins (HSP). Thirty seven males and females were randomly assigned to receive Vitamin C and E (C + E; C: 1000 mg, E: 235 mg daily) or placebo (PLA), and underwent endurance training for 11 weeks. After 5 weeks, a subgroup conducted a high intensity interval session to investigate acute stress responses. Muscle and blood samples were obtained to investigate changes in proteins and mRNA related to the antioxidant and HSP system. The acute response to the interval session revealed no effects of C + E supplementation on NFκB activation. However, higher stress responses to exercise in C + E group was indicated by larger translocation of HSPs and a more pronounced gene expression compared to PLA. Eleven weeks of endurance training decreased muscle GPx1, HSP27 and αB-crystallin, while mnSOD, HSP70 and GSH remained unchanged, with no influence of supplementation. Plasma GSH increased in both groups, while uric acid decreased in the C + E group only. Our results showed that C + E did not affect long-term training adaptations in the antioxidant- and HSP systems. However, the greater stress responses to exercise in the C + E group might indicate that long-term adaptations occurs through different mechanisms in the two groups.