Seasonal Oxy-Inflammation and Hydration Status in Non-Elite Freeskiing Racer: A Pilot Study by Non-Invasive Analytic Method

Abstract

Freeskiing is performed in an extreme environment, with significant physical effort that can induce reactive oxygen species (ROS) generation and dehydration. This study aimed to investigate the evolution of the oxy-inflammation and hydration status during a freeskiing training season with non-invasive methods. Eight trained freeskiers were investigated during a season training: T0 (beginning), T1-T3 (training sessions), and T4 (after the end). Urine and saliva were collected at T0, before (A) and after (B) T1-T3, and at T4. ROS, total antioxidant capacity (TAC), interleukin-6 (IL-6), nitric oxide (NO) derivatives, neopterin, and electrolyte balance changes were investigated. We found significant increases in ROS generation (T1A-B +71%; T2A-B +65%; T3A-B +49%; p < 0.05-0.01) and IL-6 (T2A-B +112%; T3A-B +133%; p < 0.01). We did not observe significant variation of TAC and NOx after training sessions. Furthermore, ROS and IL-6 showed statistically significant differences between T0 and T4 (ROS +48%, IL-6 +86%; p < 0.05). Freeskiing induced an increase in ROS production, which can be contained by antioxidant defense activation, and in IL-6, as a consequence of physical activity and skeletal muscular contraction. We did not find deep changes in electrolytes balance, likely because all freeskiers were well-trained and very experienced.

Keywords: electron paramagnetic resonance; inflammation; mountain; oxidative stress; saliva; skiing; training; urine.

Figure 1

Study protocol design, seasonal circle, and session training. Freeskiing athletes were tested five times throughout a competitive season: at the beginning (T0); every month (T1, T2, and T3); and two months after the end of the season (T4). Furthermore, as shown in the scheme on the right of the figure, from T1 to T3, the athletes were tested pre- (A) and post- (B) training session.

Figure 2

Histogram panel plots of the oxy-inflammation biomarkers. Time course of (A) reactive oxygen species (ROS), (B) interleukin (IL-6), (C) total antioxidant capacity (TAC), and (D) NO metabolites (NOx) at: T0, basal measure, before the season; T1, at the start of training season; T2, the middle period of the season; T3, the end of the season; and T4, two months after the end of the season. Values recorded from pre- (TA) and post- (TB) training sessions are also reported. Data are expressed as mean ± SD. Statistically significant differences comparison are displayed as: *, p < 0.05; **, p < 0.01.

Figure 3

Neopterin changes during the training season. Statistically significant differences symbols: * p < 0.05.

Figure 4

Borg and TQR scales and VAS score from all subjects. Borg scale (A) was assessed after every training session, while TQR scale (B) was assessed at the baseline (T0), before every training session, and after the season (T4). VAS scores for general wellness (C) and pain (D) were assessed at the baseline (T0), before (A) and after (B) every training session, and after the season (T4). Statistically significant difference comparisons are displayed as: * p < 0.05; ** p < 0.01.

Figure 5

Relative difference among selected measures in athletes during season (green bars) and during training session (blue bars).