Resistance training restores muscle sex steroid hormone steroidogenesis in older men

Abstract

Skeletal muscle can synthesize testosterone and 5α-dihydrotestosterone (DHT) from dehydroepiandrosterone (DHEA) via steroidogenic enzymes in vitro, but hormone levels and steroidogenic enzyme expression decline with aging. Resistance exercise has been shown to increase in plasma sex steroid hormone levels. However, it remains unclear whether resistance training can restore impaired steroidogenic enzyme expressions in older individuals. Six young and 13 older men were recruited, and muscle biopsies were taken from the vastus lateralis at basal state. The same group of older subjects underwent resistance training involving knee extension and flexion exercises for 12 wk, and post-training biopsies were performed 4-5 d after the last exercise session. Muscular sex steroid hormone levels and sex steroidgenesis-related enzyme expressions were significantly lower in older subjects than younger ones at baseline, but 12 wk of resistance training significantly restored hormone levels (DHEA: 432±26 at baseline, 682±31 pg/μg protein, DHT: 6.2±0.9 at baseline, 9.8±1.4 pg/μg protein). Furthermore, the steroidogenesis-related enzymes such as 3β-hydroxysteroid dehydrogenase (HSD), 17β-HSD, and 5α-reductase expressions were significantly restored by resistance training. We conclude progressive resistance training restores age-related declines in sex steroidogenic enzyme and muscle sex steroid hormone levels in older men.

Relationship between Dietary Protein or Essential Amino Acid Intake and Training-Induced Muscle Hypertrophy among Older Individuals

“…After the training period, 1-RM significantly increased for all exercises tested and the increase in total strength was similar between the two groups (17.2% and 17.8% for high and low intensity, respectively). Similarly, in our previous study, when healthy older men performed RT for 12 wk at 70% 1-RM (leg extension and flexion exercises; 3 sets of 10 repetitions), the increase in isokinetic and isometric leg extension strength was not significantly higher than that observed using a comparable exercise volume in the current study (p.0.10; data not shown) (29). Accordingly, low intensity resistance exercise is an effective training intensity for individuals with specific physical limitations, and for those who are apprehensive regarding their ability to undertake strength training.…”

Mail-Based Intervention for Sarcopenia Prevention Increased Anabolic Hormone and Skeletal Muscle Mass in Community-Dwelling Japanese Older Adults: The INE (Intervention by Nutrition and Exercise) Study

“…29 Several studies have shown that an exercise training program greatly increases the serum DHEA levels in older adults. 10,11 In addition, the serum IGF-1 and DHEA can be maintained at a high level by long-term training in older adults. 30 The current trial shows that physical activity was increased in the W/N and W groups.…”

“…Several studies have also shown that testosterone is increased by resistance training. 10,11 Moreover, the dehydroepiandrosterone (DHEA) and IGF-1 levels showed a good correlation. 12 The American College of Sports Medicine (ACSM) Position Stands indicate that usual walking for older adults corresponds approximately to high-intensity exercise for younger people.…”

Impact of Physical Exercise on Endocrine Aging

“…In animal and human studies, the activity of enzymes involved in sex hormone production has been found to be up-regulated in muscles by acute and chronic physical exercise [25] . Moreover, although protein expression of enzymes involved in sex hormone production was significantly lower in elderly men compared with younger men at baseline, 12 weeks of resistance exercise training significantly increased the levels of the enzymes involved in sex hormone production, and restored both serum and muscle levels of dehydroepiandrosterone, free testosterone, and DHT in older men to levels found in young subjects [28] . In this latter study, muscle steroid hormone levels were significantly correlated to muscle strength and cross-sectional area of muscles.…”