Discussion
To author’s knowledge, this was the first study to compare the immediate postexercise effects of acute bouts of golf, Nordic walking and walking on cardiometabolic markers in healthy older adults. Our findings indicate that these acute bouts of AE improve the cardiovascular profile of healthy older adults. Playing golf in particular seems to have a more positive effect on lipid profile and BG.
Acute responses to exercise-specific outcomes
In terms of HR and pace—which are intensity-related indicators—we observed predictable differences between golf, Nordic walking and walking. Previous studies have described Nordic walking as a more effective moderate-intensity exercise,26 27 whereas golf is considered low-to-moderate intensity28 29 because it involves stops, waiting and planning game strategy, thus lowering one’s HR during the game.30 In agreement with our findings, the significantly longer duration of completing a round of golf compared with other exercise types29 31 may explain why golf is a more effective exercise than Nordic walking or walking based on energy expenditure, steps and distance. The energy expenditure of golf—as a long-term, lower-intensity exercise—can also induce positive responses to the metabolism. No significant difference between these exercise-specific outcomes was observed for Nordic walking versus walking. Studies have indicated that Nordic walking requires active use of upper body muscles, which should lead to a higher HR and greater energy consumption compared with walking.27 28 32 33 The lack of any difference in our findings could be due to the evaluation technique as only 25% of participants had tried Nordic walking before.26 34
Acute responses to BG and blood lipids
In the between-group comparison, golf had a more positive effect on TGs and HDL-C than Nordic walking or walking. Golf also had a more positive effect on BG compared with walking. Interestingly, we found that golf seems to have a longer effect on TC compared with Nordic walking and walking. In addition, all the exercises reduced LDL-C and increased TGs. The exercise-specific mechanism of acute exercise on BG and lipids in healthy elderly people is not well known. Nonetheless, our study yielded similar results regarding the effectiveness of acute AE. Based on previous studies, the differences between golf, Nordic walking and walking can be explained by intensity, duration and energy expenditure even though acute effects of golf have not been studied before.5 32 33
Only a few studies with healthy adults have measured the differences in glucose concentrations between AE modalities. This is likely related to differences in carbohydrate metabolism due to the physiological differences of cycling and treadmill exercises in clinical conditions.33 This might be related to the total use of fatty acids (FAs) as an energy source. FA utilisation increases until the intensity of physical activity reaches approximately 60%–65% VO2max and 74% of the maximum HR, at which point an increase in the relative contribution of carbohydrate oxidation to energy expenditure occurs.10 This might clarify the previously reported view that the acute effect of exercise on glucose metabolism appears to require exercise near 70% VO2max.4 In our study, the intensity of golf was approximately 61%, while for Nordic walking and walking it was 76%–77% of the maximum HR. Golf affected BG more efficiently compared with walking due to a longer exercise duration, despite the lower intensity. This observation supports that a longer AE duration seems to provide a larger window for glucose concentration homoeostasis to be achieved.16 The absence of a difference in BG between golf and Nordic walking may be explained by Nordic walking requiring more muscle work, leading to a more positive impact on BG. Most studies have reported that a moderate-intensity exercise duration of around 45–60 min decreases glucose by an average approximate change of −0.83±1 mmol/L in healthy younger participants (31±21 years).35 However, in this study, BG was measured only once immediately (t=15 min) after the exercise session. Thus, there is a possibility that BG increases immediately after Nordic walking and walking but starts to decrease after a few hours as they are more intense activities than golf.
It was recently discovered that even one bout of moderate intensity AE is associated with regulation of the lipid profile, decreased concentrations of TC and LDL-C and increased HDL-C.9 Thus, in sedentary individuals, lipoprotein and lipid changes can occur even after a single exercise session where one expends at least 350 kcal.36 In this study, participants’ energy expenditure was over 350 kcal in all groups. Golf had a longer-lasting effect on reducing TC despite its lower intensity, and an immediate decrease in TC postexercise was observed in walking. It appears that an acute reduction in TGs and an increase in HDL-C seem to be related partly to the AE’s total energy expenditure, intensity and duration4 5 as well as the type of the exercise.32 In this study, only golf increased HDL-C immediately postexercise. The greater energy expenditure in golf can explain this increase compared with Nordic walking and walking, as supported by the finding that after a single exercise session, an acute increase in HDL-C was reported after energy expenditure of 350–400 and 1000 kcal in moderately fit and well-trained individuals.4 HDL-C levels were shown to be more sensitive to AE than LDL-C and TG.37 We found decreases in LDL-C and increases in TG levels in all groups. Most past studies have focused on examining a single 30–90 min acute bout of moderate intensity (60% VO2max) AE (eg, walking, jogging, cycling) in normal to overweight healthy middle-aged men to lipid profile.4 6 7 11 These studies reported that TGs significantly decreased by 8% after an acute bout of AE compared with resistance and combined exercise, but there was no difference in HDL-C or LDL-C.11 In addition, Gill et al6 examined the effects of 90 min of walking on a treadmill at moderate intensity (60% Vo2max) on serum lipid profile in middle-aged men (51±6.1 years) and reported reduced postprandial TG concentration.6 We did not observe reduces in TGs in this study. TGs can be unchanged for 4 hours postexercise, but they may occur 18–24 hours after the exercise bout.4 38 As our blood samples were taken immediately (t=15 min) after the exercise, TGs were likely still elevated as them was an energy source during the exercise.
Acute responses to BP
We found that all three exercise types decreased sBP and that Nordic walking and walking also reduced dBP. An acute bout of exercise can reduce BP during the recovery period.39 A recent meta-analysis supported that sBP decreased significantly regardless of exercise modality and that the longer the exercise session duration is, the greater the sBP reduction.40 Most studies have examined an acute bout of 20–40 min of low-intensity to high-intensity (40%–70% VO2Max) AE (eg, walking, cycling) among men with normal to high BP.12 41 It seems that the acute effect of exercise on BP is a low threshold phenomenon observed after energy expenditures requiring only 40% maximal capacity.4 In this study, sPB decreased immediately postexercise in every group. The reduction in sBP was quite similar in the Nordic walking and walking groups; this was expected as these are more intense AEs than golf. In a recent study, Ebine et al reported that the ground golf protocol reduced mean arterial BP in older adults (66±1.5 years).42 In our study, there was also a statistically significant reduction in sBP despite the lower intensity of golf. The results indicate that golf, Nordic walking and walking might have similar postexercise hypotension effects in healthy older adults. The lack of dBP in golf was expected as dBP does not change during acute low-intensity exercise.39 One past study found that walking does not reduce dBP,40 but another study also reported that dBP does not change during acute low-intensity exercise.39
While this study is focused on acute changes on cardiometabolic markers, it is important to consider the clinical significance of findings regarding the cardiometabolic markers measured. All type of AE, regardless of intensity or duration, appeared to produce favourable effects on BP in older adults. The same effect can be achieved by about 60 min of brisk walking or playing an 18-hole golf round. Aside from this finding, there were no moderate or large clinically significant changes in the other cardiometabolic markers.
Study limitations
Performing a study in a real-life environment according to typical standards allows for high generalisability, but not all factors can be controlled as in a laboratory setting. The small sample size and Fitbit Versa 3 data accuracy, especially on energy expenditure, should be considered carefully when evaluating the results. Due to the trial protocol, we recruited only golfers in the study as it was impossible to assign non-golfers to play a round of golf. Nordic walking was a new type of exercise for most participants, which may have led to poor technique and thereby decreased the effectiveness of the Nordic walking activity. Those who regularly play golf may have better overall health and be in better physical fitness, which limits the generalisability of the results to all older adults or to those with chronic conditions.