Time-Trial Performance in Elite Speed Skaters After Remote Ischemic Preconditioning.

PURPOSE: Speed skating leads to blood-flow restriction and deoxygenation in the lower limbs (especially the right leg) that may affect performance. Although the acute influence of such deoxygenation is not clearly understood, the authors tested whether remote ischemic preconditioning (RIPC) could modify muscular oxygenation and improve time-trial performance in that sport.
METHODS: Using a randomized, single-blind, placebo-controlled, crossover design, 9 elite speed skaters performed 1000-m on-ice time trials preceded by either RIPC of the upper limbs (3 × 5-min compression/5-min reperfusion cycles at 30 mm Hg >arterial systolic pressure) or placebo treatment (SHAM; 10 mm Hg). Changes in tissue saturation index, oxyhemoglobin-oxymyoglobin, deoxyhemoglobin-deoxymyoglobin, and total hemoglobin-myoglobin in the right vastus lateralis muscle were monitored using near-infrared spectroscopy (NIRS). Differences between RIPC and SHAM were analyzed using Cohen effect size (ES) ± 90% confidence limits and magnitude-based inferences.
RESULTS: Compared with SHAM, RIPC had a negligible effect on performance and NIRS variables. However, in a subgroup of sprinters (n = 5), RIPC likely lowered tissue saturation index at the beginning of the time trial (-6.1%; ES = -0.65) and likely increased deoxyhemoglobin-deoxymyoglobin at the beginning (3%; ES = 0.39), middle (2.9%; ES = 0.37), and end of the trial (-2.1%; ES = 0.27). In the middle section of the trial, these metabolic changes were concomitant with a possible increase in total hemoglobin-myoglobin.
CONCLUSION: RIPC has no practical ergogenic impact on 1000-m long-track speed-skating performance in elite athletes. The relevance of using RIPC during training to increase physiological stress in sprinters particularly deserves further investigation.

RCT Entities:   Population Interventions Outcomes