У вашего броузера проблема в совместимости с HTML5
I don’t recommend wearing socks for short course racing or training (sprints and Olympic distance triathlons) because it slows you down.
Not wearing socks can save you tons of time in your transitions. Putting dry socks on wet feet while balancing on one leg is no easy task, especially when your heart rate is at 160 or higher. So, why not learn to race with no socks. It’s simple really!