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Best Time for Workouts: Morning vs Evening Testosterone- Thomas DeLauer…
Study – The Journal of Clinical Endocrinology and Metabolism: Looked at the effect of diurnal variation on serum testosterone levels in men – blood samples were collected at six separate visits, three morning visits 1-3 days apart and three afternoon visits 1–3 days apart. 66 men participated, 30–80 years of age – in men 30–40 years old, testosterone levels were 20–25% lower at 4pm than at 8am – the difference declined with age, with a 10% difference at 70 years.
REM Sleep & Testosterone:
Serum testosterone levels were determined every 20 min between 1900–0700 h with simultaneous sleep recordings during the 7-min sleep attempts. The results were compared with those obtained in men during continuous sleep. Although mean levels and area under the curve of testosterone were similar in both groups, fragmented sleep resulted in a significant delay in testosterone rise (03:24 h ± 1:13 vs. 22:35 h ± 0:22)
During fragmented sleep, nocturnal testosterone rise was observed only in subjects who showed REM episodes (4/10) – findings indicate that the sleep-related rise in serum testosterone levels is linked with the appearance of first REM sleep. The rise in testosterone levels was slower when REM latency was longer in young adult men, testosterone levels begin to rise on falling asleep, peak at about the time of first REM, and remain at the same levels until awakening.
Morning vs Evening Workouts Study – Study – journal PLoS One:
Looked at the effect of time of day on performance, hormonal and metabolic response during a 1000-M cycling time trial in 9 recreational cyclists, average age 31. The participants performed a 1000-m TT at either 8 am or 6 pm, in randomized, repeated-measures, crossover design a 1000-m cycling time-trial. The time to complete the time trial was lower in the evening than in the morning (88.2 vs 94.7, respectively), but there was no significant different in pacing. However, oxygen uptake and aerobic mechanical power output at 600 and 1000 m tended to be higher in the evening. There was also a main effect of time of day for insulin, cortisol, and total and free testosterone concentration, which were all higher in the morning (+60%, +26%, +31% and +22%, respectively) The norepinephrine response to the exercise was increased in the morning (+46%), and it was accompanied by a 5-fold increase in the response of glucose.
References:
1) The Effect of Diurnal Variation on Clinical Measurement of Serum Testosterone and Other Sex Hormone Levels in Men. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2681273/
2) Welliver RC Jr , et al. (n.d.). Validity of midday total testosterone levels in older men with erectile dysfunction. – PubMed – NCBI. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24518771/
3) Crawford ED , et al. (n.d.). Measurement of testosterone: how important is a morning blood draw? – PubMed – NCBI. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/26360789
4) PURLs: It’s time to reconsider early-morning testosterone tests. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4501456/
5) Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy MenFREE. (1). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4445839/
6) Effect of Time of Day on Performance, Hormonal and Metabolic Response during a 1000-M Cycling Time Trial. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4188634/
7) Morning and evening exercise. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5481716/
8) Role of Sleep and Sleep Loss in Hormonal Release and Metabolism. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065172/
9) Disruption of the Nocturnal Testosterone Rhythm by Sleep Fragmentation in Normal Men | The Journal of Clinical Endocrinology & Metabolism | Oxford Academic. (2001, March 1). Retrieved from https://academic.oup.com/jcem/article/86/3/1134/2847605
10) Luboshitzky R , et al. (n.d.). Relationship between rapid eye movement sleep and testosterone secretion in normal men. – PubMed – NCBI. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/10591612
11) The relationship between sleep disorders and testosterone in men Wittert G – Asian J Androl. (2014, March 1). Retrieved from http://www.ajandrology.com/article.asp?issn=1008-682X;year=2014;volume=16;issue=2;spage=262;epage=265;aulast=Wittert
12) The relationship between sleep disorders and testosterone in men Wittert G – Asian J Androl. (2014, March 1). Retrieved from http://www.ajandrology.com/article.asp?issn=1008-682X;year=2014;volume=16;issue=2;spage=262;epage=265;aulast=Wittert
13) https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.1939-4640.1999.tb03378.x