No other such studies had been carried out, so their objective was to identify risk factors and cardiac abnormalities. Health impacts of vigorous, strenuous exercise included stress on the heart, raised blood pressure, irregular heart rhythms and, in the case of competitive sports like hockey, could result in a heart attack. This suggested that moderate exercise would be less of a risk and so, more beneficial. The experience and credentials of the researchers gave credibility to their hypothesis.
Methods: Qualitative and quantitative data was obtained from the volunteer hockey players, using a general health questionnaire, laboratory tests and electric heart monitors during games. The findings could be applied to other areas of intensive exercise, as detail provided would allow for replication, with all processes fully described. Table 1 (p.304) showed that over 50% had elevated total cholesterol, and 36.3% had a family history of heart disease, so strenuous exercise was not the best option for those with these health factors. " Not all volunteers completed the general questionnaire or underwent baseline testing" Atwal et al (2002), which could have uncovered relevant confounding variables. Difficulties arose in the use of monitors, as some became detached, but were used in later games to obtain the necessary data for analysis. Observed heart rates (HR_) were studied to see how these exceeded target heart rate (THR_) and age predicted HR_, and to determine how long the faster HR_ continued one minute after exercise, as well as other abnormalities in heart action. The thorough analysis, explained in the results, supported the researchers' belief that strenuous exercise posed risks. They had stated earlier that "mild to moderate exercise.is associated with better fitness and fewer cardiac events" Atwal et al, p.303), and the findings proved this to be the case.
Results: Though the 113 volunteers, with a mean age of 42.7 years, had cardiac risk factors and lower total cholesterol than the general population, as shown in Tables 1 and 2, all the players, after games, had heart rates that exceeded target and maximum HR_, and heart rate recovery was poor. This was illustrated in the graph at Fig. 1 (p. 305); all the subjects exceeded target and age predicted rates. So despite the amount of exercise taken weekly by the players, the type of exercise appeared to be less beneficial. When moderate exercise such as walking for 45 minutes per day, or jogging for 20 minutes, is used, less strain is put on the heart, levels of HDL (good cholesterol) are raised, while the heart muscle is strengthened and the resting HR_ is slowed. All such factors would reduce the risk of cardiac events. It was also found that 19 players suffered tachycardia and ventricular abnormalities and were given additional stress tests that eventually produced normal results. But the findings in this study proved the hypothesis of the potential risks of strenuous