Cardiovascular effects of strenuous exercise in adult recreational hockey: the Hockey Heart Study
Sanita Atwal, Jack Porter and Paul MacDonald
CMAJ February 05, 2002 166 (3) 303-307;
There is a well-known trend for adult hockey players of all skills to join recreational hockey leagues as they become too old to play in competitive leagues as they did in their youth. In Canada, there are more than 500 000 men who play in these leagues. The reality of these men’s leagues is that most of the players treat their one or two games a week as their only physical activity for the week. On top of this, they often only get about 2 minutes of light warm up as they get on the ice before the game.
This study recruited 113 male recreational league hockey players to see if this “weekend warrior” behavior had any negative cardiovascular effects on these types of players. In other words, to look at if doing high-intensity activity playing hockey once or twice a week without proper warm-up would cause a dangerous strain on these men’s cardiovascular systems. To do so, they looked at the baseline cardiac risk factors of the 113 volunteers (Table 1 below). As well, each one of the players underwent Holter electrocardiographic monitoring before, during and after at least one hockey game to assess the player’s heart rates, any occurrence of arrhythmias, ST-segment changes and for correlation with symptoms and other predictors of fitness.
When looking at the maximum heart rate the players reached in this study while playing, the mean maximum heart rate was 184 beats/min. General recommendations for healthy and safe physical activity in Canada recommends that the maximum heart rate that should be targeted during exercise to be between 65% to 85% of the age-predicted maximum heart rate (HRmax = heart rate of 220 – age in years). Studies have shown that anything of higher intensity causing the heart rate to go above this range can potentially to lead to an increase in frequency of cardiac events and sudden death. In this study, all of the players had a maximum attained heart rate higher than this suggested range of 65%-85% (Graph 1 below). Furthermore, the mean period for which these player’s heart rates exceeded 85% of the age-predicted maximum heart rate was 30 minutes. For 70.1 % of the player’s heart rates recovery was poor post-exercise. Non-sustained ventricular tachycardia was seen 2 Holter monitoring sessions, atrial fibrillation was seen in one subject and ST-segment depression in data from 15 sessions. However, of these patients with irregular heart rhythms, none had irregular follow-up cardiac stress work-ups.
This study suggests that the recreational hockey player faces an exercise intensity that can be dangerous to their health as seen in all the cases of this study. Even though each of the participants had higher than recommended maximum heart rates and some even had abnormal Holter findings there were no adverse events and no abnormal follow-up cardiac studies. Canadian exercise recommendations suggest at least 150 minutes of moderate to vigorous intensity aerobic physical activity per week, in bouts of 10 minutes or more. Studies have shown that engaging in 4 or more per week resulted in a reduced relative risk of myocardial infarction. Ideally, recreational ice hockey players as well as any high-intensity sports participant should be aware of these risks and should be advised by their primary care health providers to train their cardiovascular system gradually and regularly to be able to do this high-intensity exercise. It is often noted that when we get older playing high-intensity sports is a privilege and not a right; to continue to have the privilege of playing hockey, these “weekend warriors” should be encouraged to integrate regular cardiovascular exercise into their weekly routine. When we are young and in competitive leagues, we practice on a regular basis to prepare for our games. As adult athletes, we must take the same approach of preparation for our games but with the focus on exercise tolerance as oppose to on performance as is the case when we are younger.