Suunto t4 Environment: Endurance sports with competitive endeavor: running, cycling, Nordic skiing, triathlons and more. The Suunto t4 is another excellent addition to Suunto’s growing line of fitness training wristop computers. Like all of Suunto’s t-Series training watches (the t1, t3, t4, and the original t6) the t4 monitors your heart rate and caloric burn [...]