Primary article review and analysis

¶ … Cooling Strategies

Price, M.J., Boyd, C. And Goosey-Tolfrey, V.L. 2009. The physiological effects of pre-event and midevent cooling during intermittent running in the heat in elite female soccer players Appl. Physiol. Nutr. Metab. 34: 942 -- 949 doi:10.1139/H09-078.

The objective of this study was to examine the effects of cooling strategies, which involved placing ice vests on elite female soccer players during simulated match play. This ice vests were placed on the soccer players at the beginning (PRE) and midpoint (MID) of exercise. Heat content and skin and rectal temperatures of the soccer players were determined at these time points and compared to no cooling (no ice vest). These temperatures were taken while the players were in a controlled heat environment, simulating hot weather. The main findings were that both cooling protocols before and during exercise were beneficial when compared with no cooling. In addition, cooling both before and during exercise was more effective than just prior to exercise alone, reducing heat storage during the second half of the exercise protocol. The authors conclude that the extra 15 -- 20 min of cooling achieved for PRE+MID when compared with PRE-may translate into improved performance during "extra time" in soccer. According to the authors, when possible, midevent cooling in hot conditions should be considered.

The article overall was well written and understandable, placed within accessible scientific content. The questions the research addresses about adequate methods of cooling during intense exercise are definitely worthwhile answering. The approach is a well-conceived one: The use of ice vests to determine cooling strategies during activity in hot weather was well explained. The graphs nicely illustrated how temperature and heat content decreased during PRE and PRE+MID as compared to CON, although Figure 2 does not indicate what the projecting lines mean. There is adequate referencing of previous studies to give good background to the current study and why they were performing it. The background gave a good introduction to gaps in the current state of knowledge about cooling strategies during exercise, particularly in women.

However, there are flaws in the overall protocols used and methodology, which may serve to question the conclusions of article. First, the article states that the female soccer players only moved on a treadmill, excluding lateral and sideways movement. On the soccer field, these latter moves are common and whether the ice vest would be effective with a more diverse set of movements is unknown. However, the running speeds do simulate soccer activity well.

Furthermore, the authors note that the soccer players drank fluid during the experiment. Whether the cooling was due to the ice vest, the fluids, or both is indeterminate. The fluid intake varied during CON, PRE and PRE+MID as illustrated in Table 1. Also, the sweat rate was measured. It is not addressed in the paper that sweating contributes to cooling.