Effect of warm-up exercise on exercise-induced bronchoconstriction
Stickland MK, Rowe BH, Spooner CH, Vandermeer B, Dryden DM. Med Sci Sports Exerc. 2012 Mar;44(3):383-91.
Following a warm-up that induces exercise-induced bronchoconstriction (EIB), a temporary airway narrowing associated with exercise, some individuals experience a 1 to 4 hour refractory period during which they have less severe or no EIB after additional vigorous exercise. Numerous warm-up programs have been suggested to induce a refractory period but it is unclear how effective they are. Therefore, Stickland et al conducted a systematic review to evaluate the effectiveness of different warm-up routines to cause a refractory period. In August 2009, the authors searched the literature for randomized clinical trials that assessed the influence of warm-ups on adults or children with EIB. Warm-up routines were classified into four groups: 1) interval high-intensity, 2) continuous low-intensity, 3) continuous high-intensity, and variable intensity warm-ups (e.g., a combination of low and very high intensity). Among the seven studies the authors identified the interval high-intensity and variable intensity warm-ups decreased EIB. In contrast, continuous low-intensity and continuous high-intensity warm-ups did not. The interval protocols involved repetitive sprints of 26 to 30 seconds at 100% maximal oxygen consumption (or higher; the article provides a table giving more details). One of the variable intensity warm-ups included 6-minute treadmill run, a 10-minute rest followed by 7 30-second sprints, and finally a 20-minute rest before the final 6-minute treadmill run.
This systematic review is interesting because it highlights that an appropriate warm-up protocol could function as a short-term nonpharmacological alternative for reducing EIB. The authors note that the interval high-intensity warm-up “may be superior as it is a more easily standardized for the athletes/coach, and there is more evidence for this strategy”. A simple interval program may be particularly valuable because some athletes may be able to perform the 15 to 30 minute warm-up without direct supervision; saving staff time. While this review provides support for interval high-intensity and variable intensity warm-ups (e.g., warm-ups with maximal-exertion sprints) more research in this area may help optimize the benefits of these warm-ups. Furthermore, it will be interesting to see how these warm-ups compare to inhalers. Do you feel that these warm-ups could be beneficial for your athletes? Do you have athletes perform these warm-ups?
Written by: Jeffrey Driban
Reviewed by: Stephen Thomas
Stickland MK, Rowe BH, Spooner CH, Vandermeer B, & Dryden DM (2012). Effect of warm-up exercise on exercise-induced bronchoconstriction. Medicine and Science in Sports and Exercise, 44 (3), 383-91 PMID: 21811185