Decreases in resting plasma beta-endorphin and depression scores after endurance training

That endurance training changes resting plasma beta-endorphin (BE) at the same time that there are improvements in non-clinical depression was tested in medically healthy middle-aged men (40-60 years). Subjects were self-selected based on compliance into treatment (T, n = 10) and placebo (P, n = 6) groups. T attended an eight month fitness program. P had less than 50% attendance in the program. Treadmill tests at the pre and post program were used to estimate the Physical Fitness Score (PFS). The Minnesota Multiphasic Personality Inventory (MMPI) was used to measure depression. All psychological scores were within non-pathological, normal limits. BE was measured with the subjects fasting and resting in the early morning. BE, detected by radioimmunoassay, decreased (p less than .005) from pre 48.53 +/- 3.32 (SE) to post 31.73 +/- 4.43 pg/ml in T. The MMPI depression score also decreased in T (p less than .05) from pre 58.90 +/- 2.81 (SE) to post 53.20 +/- 1.48 T-score units. In contrast, the PFS increased in T (p less than .005) from pre 254.57 +/- 18.62 (SE) to post 304.94 +/- 15.95 PFS units. No pre to post program changes were detected in P. In conclusion, endurance training of eight months duration appeared to decrease the resting plasma BE concentrations and the MMPI depression scores of the middle-aged men in the present study.

Beta-endorphin and components of emotionality discriminate between physically active and sedentary men

Differences between physically active and sedentary men were tested by profile comparison. The study identifies the relative importance of circulating beta-endorphin (BE), atherosclerotic disease risk (ADR) index, and selected components of emotionality in discriminating between physically active and sedentary men. The subjects were psychologically normal and medically healthy middle-aged men. Jogging activity was the subject classification criterion. The data were collected on selected physiological (treadmill), biochemical (blood collected from resting subjects), and psychological (Eysenck and MMPI) variables. The physical fitness score (PFS) was used as an index of fitness. Physically active men with a high PFS (n = 21), when compared to the sedentary men with a low PFS (n = 15), exhibited lower basal plasma BE, lower ADR, lower anxiety index (AI), and lower MMPI depression score (D). Canonical correlation analysis showed that PFS and BE in one set were correlated with D and neuroticism (NS) in another set of variables. Discriminant function analysis showed that the AI was the most powerful discriminator between the physically active and sedentary men, followed by BE and NS. Interestingly, BE and NS exhibited the same magnitude of discrimination power. The ADR exhibited less discrimination power, relative to AI, BE, and NS. In conclusion, the physically active men, compared to the sedentary men in this study, exhibited lower basal plasma BE, which appeared to be associated with less atherosclerotic disease risk, less neuroticism, less anxiety, and less depression.

Decreases in resting plasma beta-endorphin/-lipotropin after endurance training

The purpose of the present study was to investigate changes in the resting plasma beta-endorphin/-lipotropin (beta E/beta-LPH) concentration that may occur with exercise training. A treatment group (N = 10) of previously sedentary, psychologically normal, and medically healthy middle-aged men trained for 4 months in a structured fitness program. The treatment group was compared with two age-matched groups: a jogger group (N = 10) and a sedentary group (N = 10). Venous blood was collected in the early morning after the subjects had been fasting for at least 12 h. The subjects were also resting at the time of blood collection. Resting plasma beta E/beta-LPH (measured by radioimmunoassay) decreased (P less than 0.05) following the 4 months of exercise training in the treatment group, from 11.01 +/- 1.62 (SE) to 7.22 +/- 0.99 pmol.1-1. The jogger and sedentary groups demonstrated no changes in the resting plasma beta E/beta-LPH concentration following the 4 months. Aerobic fitness, measured by the maximal oxygen uptake (VO2max), increased (P less than 0.01) from 36.56 +/- 2.58 (SE) to 44.85 +/- 1.34 ml.kg-1.min-1 in the treatment group after the 4 months of training. There were no changes in VO2max for either the jogger group or the sedentary group following the 4 months. In conclusion, beta E/beta-LPH in the plasma of resting middle-aged men appeared to be decreased after 4 months of aerobic training.

Beta-endorphin and components of depression as powerful discriminators between joggers and sedentary middle-aged men

This study identifies the relative importance of resting plasma beta-endorphin, used as a marker of perceived stress, and components of non-clinical depression that discriminate between physically active joggers and sedentary men. The profiles of joggers (n = 10) and sedentary (n = 10) middle-aged men (40-60 yr) were compared. The jogger group had been running about 20 miles per week for at least 3 yr.

RESULTS

as expected, the joggers exhibited greater physical fitness, but lower circulating beta-endorphin (measured with the subjects at rest). The joggers also exhibited greater emotional stability (Eysenck scores), and lower depression (MMPI Scale 2 scores). In addition, the joggers had lower scores on MMPI subscales of depression: subjective depression, physical malfunctioning, mental dullness, and brooding. Multivariate discriminant function analyses showed that subjective depression, beta-endorphin, and physical malfunctioning were powerful discriminators between the jogger and sedentary groups.

IN CONCLUSION

(1) subjective depression appeared to be the MMPI component of depression that most powerfully discriminated between joggers and sedentary middle-aged men in this study. (2) Lower beta-endorphin may be an adaptation to exercise training and was related to greater emotional stability and lower depression, especially lower subjective depression. (3) The lower beta-endorphin in the jogger group may be related to lower perceived stress in the joggers, relative to the sedentary group.

Depression as a powerful discriminator between physically active and sedentary middle-aged men

This study identifies the relative importance of psychological dimensions that discriminate between habitually physically active and sedentary men. The data support the notion that physical activity has psychological benefits. Subjects (N = 22) were normal, medically healthy middle-aged men (40-60 years of age). Data were collected on selected physiological (treadmill) and psychological (MMPI) variables and replicated within four months. The Student's t-test and discriminant function analysis were used in the statistical analysis. Physically active men (n = 11) have lower depression (scale 2) and lower social introversion (scale 10) than the sedentary men (n = 11). The physically active men may exhibit MMPI scale differences in 'neurotic' tendencies from the sedentary men, but there is no apparent difference in scales suggestive of 'psychotic' tendencies. Depression (scale 2) is the most powerful discriminator between physically active and sedentary men, followed by hysteria (scale 3) and social introversion (scale 10). In conclusion, our data identify depression as the most important MMPI scale that discriminates between physically active and sedentary men.