It is well known that an Ironman triathlon can induce considerable physical and psychological stress on its participants, and that completion of an Ironman triathlon results in muscle damage, as indicated by reduction in muscle function and soreness. However, the timeframe of physiological responses following an Ironman is a critical question that has rarely been addressed.
Written by: Tim Mickleborough, Ph.D.
Recently, Ken Nosaka and colleagues at Edith Cowan University in Australia (1) published a study in which they collected data on blood markers of muscle damage and inflammation, muscle function, muscle soreness, running economy and VO2 max for one male triathlete while cycling before and days after the 2006 Ironman Western Australia. The athlete had a personal best time of 10 hours, 14 minutes and finished the race in 11:38. He finished the swim in 1:17, the bike in 5:25 and the run in 5:06, which was about one hour slower than expected due to fatigue related to hyperthermia and muscle cramping near the halfway point of the run.
Before and on several occasions during the 15 days after the event, the athlete performed an incremental cycling test to exhaustion, running economy test at 12 km/hour (on a 2 percent incline), tests of maximal isometric knee flexion and extension at 90-degree knee flexion, and maximal squat and countermovement jumps. Venous blood samples and muscle soreness were also assessed. The authors found that VO2max, efficiency of motion, maximal muscle strength and jump performance were significantly reduced—by 4.5-54 percent—initially, but returned to baseline values within eight days.
An obvious limitation of this study is that it was a case study, meaning it only involved one athlete, and therefore the findings cannot necessarily be generalized to the athlete population as a whole. However, the same research group (2) obtained similar results in an earlier study involving a larger group of nine Ironman participants.
In another study, Oliver Neubauer and colleagues at the University of Vienna (3) obtained blood from 42 well-trained male triathletes after the 2006 Ironman Austria and investigated instances of muscle damage and systemic inflammation for up to 19 days after recovery from the race. The main findings of the study (3) were that markers of muscle damage were still altered five days after the race, and that a few markers of muscle damage and systemic inflammation were still elevated 19 days post-race. The authors concluded that, from the perspective of the observed muscle repair and inflammatory processes, at least two to three weeks of active recovery is advisable before returning to more intensive training.
An important factor to consider is that how well your body recovers from an Ironman triathlon may be related to the level of muscle damage sustained before the race. Robert Hikida and colleagues at Stellenbosch University in South Africa (4) performed muscle biopsies on a group of marathon runners before and after a competitive marathon and not only documented muscle cell damage for up to seven days after the race but also observed damage in the muscle cells in the pre-race samples.
The authors concluded that both intensive training leading into the race and the marathon itself can induce muscle cell damage, which is another very good reason for an athlete to implement an effective taper program leading into an Ironman triathlon.
We do not yet know how long it takes to truly recover from muscle damage sustained in an Ironman triathlon. However, it likely takes much longer than most athletes are currently prepared to allow.
1. Nosaka, K., C.R. Abbiss, G. Watson, B. Wall, K. Suzuki, and P. Laursen. “Recovery following an Ironman triathlon: A case study.” European Journal of Sports Science. 10, 3 (2010): 159-165.
2. Suzuki, K., J. Peake, K. Nosaka, M. Okuttsu, C.R. Abbiss, R. Surriano, D. Bishop, M.J. Quod, H. Lee, D.T. Martin, and P.B. Laursen. “Changes in markers of muscle damage, inflammation and HSP70 after an Ironman triathlon race.” European Journal of Applied Physiology. 98 (2006): 525-534.
3. Neubauer, O., D. Konig, and K-H. Wagner. “Recovery after an Ironman triathlon: sustained inflammatory responses and muscular stress.” European Journal of Applied Physiology. 104 (2008): 417-426.
4. Hikida, R.S., R.S. Staron, F.C. Hagerman, W.M. Sherman, and D.L. Costill. “Muscle fiber necrosis associated with human marathon runners.” Journal of Neurological Sciences. 59, 2 (1983): 185-203.