The research: Lead researcher David C. Nieman, DrPH, and his team at Appalachian State University in North Carolina looked at the blood of cyclists and runners who exercised for 2.5 hours a day for three days in a lab at 70% VO2 max (a measure of oxygen uptake). Working out at 70% VO2 max is the level where you can have a breathy conversation while exercising—you’re not totally out of breath, but conversation’s a bit of a challenge. Blood samples were taken pre-exercise and then two more times over the three test days. The result: the runners’ blood showed greater muscle damage, inflammation, and delayed onset muscle soreness (DOMS) than the cyclists. What it means: Runners suffer much more for their sport due to the increased damage to their muscles than cyclists, regardless of their experience, says Dr. Nieman, a seasoned marathoner. That’s because running contains an eccentric muscle contraction component, and cycling does not. “The eccentric component occurs when you’re trying to contract your muscles as they’re lengthening,” he explains. Think of it like this, Dr. Nieman says: The contraction is like trying to do a pull-up while someone’s trying to pull you down. “Every time your heel hits the ground, there’s a bit of muscle contraction with lengthening that goes on, which is where the muscle gets damaged,” he says. The bottom line: If you enjoy running there’s no need to swap your running shoes for wheels completely, just mix it up. “I recommend switching back and forth between cycling and running,” Dr. Nieman says. If you’re starting a running program, do so gradually with 10 to 15 minutes initially, and then working up to 30 minutes or longer. And if you hate running? Consider this your guilt-free excuse for taking it off your fitness to-do list. More from Prevention: Are You Running The Wrong Way?
