Table 1. Descriptive statistics of the average, minimum and maximum heart rate variation (beats·min) for sleep for each of the three sessions for each of the ten subjects. Data are expressed as the mean. Subject Average Heart Rate Minimum Heart Rate Maximum Heart Rate SES1 SES2 SES3 SES1 SES2 SES3 SES1 SES2 SES3 1 74 66 72 60 56 60 98 95 92 2 45 53 51 36 39 42 82 113 85 3 66 59 69 56 52 56 101 98 90 4 69 63 65 59 53 56 106 107 105 5 63 63 64 53 53 53 94 116 100 6 73 76 77 57 64 65 106 100 104 7 62 62 65 51 50 53 103 97 91 8 65 66 69 47 52 57 100 104 107 9 70 69 66 58 57 55 89 100 94 10 58 58 67 47 48 40 91 100 110 Mean 65 63 67 52 52 54 97 103 98 SD 9 6 7 7 6 8 8 7 9 Abbreviations: SES= Session, SD= Standard deviation.