Use of heart rate reserve and rating of perceived exertion to prescribe exercise intensity in diabetic autonomic neuropathy.
ABSTRACT Individuals with diabetic autonomic neuropathy (DAN) exhibit an increased resting heart rate but depressed maximal heart rate. Thus, the purpose of this study was to examine the validity of using either percent of heart rate reserve (HRR) or a rating of perceived exertion (RPE) scale to prescribe exercise intensity in diabetic individuals both with and without DAN.
The subjects consisted of 23 individuals with type 2 diabetes, ages 45-75 years, with (DAN; n = 13) or without (No DAN; n = 10) clinical signs of DAN, as assessed by heart rate variability using the expiration-to-inspiration ratio of the R-R interval. Peak aerobic capacity was determined using a graded protocol on a cycle ergometer, with RPE, heart rate, and VO(2) values recorded at each stage.
The subjects were similar with the exception of depressed autonomic function in DAN subjects. Peak respiratory exchange ratio values were significantly higher (P < 0.05) in the DAN group (1.08 +/- 0.02 vs. 1.02 +/- 0.01 in No DAN subjects), although DAN subjects exhibited a significantly lower (P < 0.05) peak exercise heart rate. A similarly highly linear relationship between %HRR and percent VO(2) reserve (VO(2)R) existed for both groups (r = 0.98). A similar slightly weaker relationship (r = 0.94) was found between RPE and %VO(2)R.
In conclusion, in diabetic individuals, %HRR provides an accurate prediction of %VO(2)R and can be used to prescribe and monitor exercise intensity, regardless of the presence of DAN. The RPE scale is also a valid, albeit slightly less accurate, method to monitor exercise intensity in diabetic individuals.
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- "Again, the time course of the _ VO 2 response was not reported, but the mean ± SD resting _ VO 2 of 3.0 ± 0.40 mL kg -1 min -1 was very similar to the present study. Other studies have assessed resting _ VO 2 using only 3 min for acclimation and 10 min for assessment, making the achievement of a _ VO 2 steady state unlikely and the accuracy of the resting _ VO 2 values questionable (Colberg et al. 2003; Davenport et al. 2008; Mezzani et al. 2007; Rotstein and Meckel 2000; Swain and Leutholtz 1997; Swain et al. 1998 "
ABSTRACT: The time necessary to obtain a steady state for an accurate and reliable assessment of resting VO2 remains unclear and was the purpose of this study. Thirty healthy men, aged 17-28 years, visited the laboratory twice for the assessment of resting VO2, which was assessed as follows: (a) 24 h abstention from physical exercise, alcohol, soft drinks and caffeine, (b) fasting for at least 8 h, (c) an acclimation period of 10 min, and (d) 60 min assessment in a supine position. Resting VO2 significantly changed during the 60 min (F = 37.4, P < 0.001), exhibiting a monoexponential decrease before reaching an asymptote. Post hoc pairwise comparisons showed that significant differences existed between consecutive means until the 30 min time point, after which there were no significant differences. The VO2 response across trials exhibited high test-retest reliability, with within-subject coefficients of variations at each time point ranging from 2.8 to 7.0 % and intraclass correlation coefficients ranging from 0.90 to 0.99. The reliability was higher from the 25 min time point onwards. Based on these findings, the following recommendations are made to promote accurate assessment of resting VO2: (a) initiate the resting VO2 measurement with 10 min of acclimation to the assessment apparatus, (b) determine resting VO2 for a minimum of 30 min, until an apparent VO2 steady state has been achieved; and (c) determine resting VO2 for a further 5 min, with the average of this last 5 min of data being regarding as the resting VO2.Arbeitsphysiologie 12/2013; 113(6):1441-1447. DOI:10.1007/s00421-012-2571-x · 2.30 Impact Factor
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- "Rather, Swain and colleagues (Swain and Leutholtz, 1997; Swain et al., 1998) showed that %HRR values are more closely related to the values of %V ˙ O 2 reserve (%V ˙ O 2R ), i.e., to a percentage of the difference between resting and peak oxygen uptake. Similar conclusions have been reached in recent studies with obese subjects (Byrne and Hills, 2002), heart disease patients (Brawner et al., 2002), diabetic individuals (Colberg et al., 2003), and elite road cyclists (Lounana et al., 2007). While research has demonstrated that HR is a valid tool to prescribe exercise intensity for lower-body exercise, very few studies have investigated the HR-V ˙ O 2 relationship for upperbody exercise. "
ABSTRACT: Previous studies have demonstrated that during lower-body exercise the percentage of heart rate reserve (%HRR) is equivalent to the percentage of the oxygen consumption reserve (%V˙O(2R)) but not to a percentage of the peak oxygen consumption (%V˙O(2peak)). The current study examined these relationships in trained surfboard riders (surfers) during upper-body exercise. Thirteen well-trained competitive surfers performed a stepwise, incremental, prone arm-paddling exercise test to exhaustion. For each subject, data obtained at the end of each stage (i.e., HR and V˙O(2) values) were expressed as a percentage of HRR, V˙O(2peak), and V˙O(2R) respectively and used to determine the individual %HRR-%V˙O(2peak) and %HRR-%V˙O(2R) relationships. Mean slope and intercept were calculated and compared with the line of identity (slope=1, intercept=0). The %HRR versus %V˙O(2R) regression mean slope (0.88±0.06) and intercept (20.82±4.57) were significantly different (p<0.05) from 1 and 0, respectively. Similarly, the regression of %HRR versus %V˙O(2peak) resulted in a line that differed in the slope (p<0.05) but not in the intercept (p=0.94) from the line of identity. Predicted values of %HRR were significantly higher (p<0.05) from indicated values of %V˙O(2R) for all the intensities ranging from 35% to 95% V˙O(2R). Unlike results found for lower-body exercise, a given %HRR during prone upper-body exercise was not equivalent to its corresponding %V˙O(2R). Thus, to ensure more targeted exercise intensity during arm-paddling exercise, individual HR-V˙O(2) equations should be used.Journal of PHYSIOLOGICAL ANTHROPOLOGY 11/2010; 29(6):189-95. DOI:10.2114/jpa2.29.189 · 1.16 Impact Factor
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- "Even if, in the majority of cases, this method is safe for our health, in some cases, its use, in conjunction with the absence of qualified supervision, could be dangerous for health. In fact, ambient temperature, emotional stress, high humidity, caffeine, medications, dehydration, postural position, size of muscle mass involved in exercise, fatigue and illnesses (Ainslie et al., 2003; Colberg et al., 2003; Dehne and Protas, 1986; Freedson and Miller, 2000; Sirard and Pate, 2001) can all influence HR, altering the real work done and the blood pressure response. In adjunction, Weltman and colleagues (1989; 1990) reported that, in both sedentary men and women, exercise performed at a specified percentage of HR max (%HR max ) and heart rate reserve (%HRR) elicited a wide range of metabolic responses, suggesting that the use of standard HR intensity guidelines results in different levels of metabolic stress across subjects (Meyer et al., 1999). "
ABSTRACT: Pre-participation screening is very important for prescribing and practising exercise safely. The aim of this study was to investigate both ratings of perceived exertion (RPE) and blood pressure responses in two different types of exercises with matching duration and indirectly determined working heart rate (HR). Participants were 23 male students, who were generally healthy but sedentary. The time course of their RPE and blood pressure during a 50- minute work-out session on an arm crank ergometer and a cross trainer were compared. RM-ANOVA showed both a higher RPE (p < 0.001) and diastolic blood pressure (DBP) (p < 0.001) response to the arm exercise that were shown significantly correlated (r = 0.883; p = 0.008). Linear regression analysis (p = 0.001) confirmed the ability to predict the time course of DBP by knowing the RPE on the arm crank ergometer. Even if people use the recommended relative intensity, the HR method is not always safe for health without pre-participation screening because exercise characteristics can negatively influence physiological responses. The HR method could be substituted by the RPE method. Key pointsArm Crank Ergometer elicits a higher diastolic blood pressure response respect to Cross Trainer when people exercise at the same heart rate.Arm Crank Ergometer elicits a higher ratings of perceived exertion respect to Cross trainer when people exercise at the same heart rate.Indirect determined working heart rate is not always safe even if the theoretical intensity is that recommended for health.Rating of perceived exertion method should be used instead of heart rate method to avoid the dangerous physiological responses observed.Journal of sports science & medicine 01/2009; 8(3):401-9. · 0.90 Impact Factor