PezCycling News - What's Cool In Road Cycling : Evening Exercise and Sleep Quality?

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Evening Exercise and Sleep Quality?
It can be challenging to fit training in around our busy lives. Some adapt by training in the evening after the rest of “life” gets done. Does hard exercise in the evening, and the attendant stimulus, affect our sleep quality and subsequent recovery?

Mario Cipollini slaapt met de cup na zijn zege in Milano-Sanremo, foto HB/Cor Vos ©2002

Hopefully we are all aware of the classic equation of Stress + Rest = Growth re-popularized by Brad Stulberg and Steve Magness in their book ”Peak Performance.

Applicable to so many aspects of our lives, this simple equation is fundamental to training:
• Do hard hammer rides every day and you’ll stagnate and eventually go slower rather than faster.

• Lift heavy weights and do the same exercises every session and your muscles will break down rather than grow.

A lot of training, therefore, is balancing hard training as sufficient and appropriate stimulus, and then resting/recovering to give your body the chance to adapt and make itself stronger. Most of us find it no challenge at all to train hard. Much more challenging is having the discipline to rest and recover, whether that’d be easier rides, days off the bike, or proper fueling.

Possibly the biggest key to the rest side of the equation is sufficient amounts of quality sleep, with most adults requiring at least 7-8 h nightly and athletes even more.

Thomas et al. 2019
But if we’re busy all day with work and family, and are forced to train in the evening or early night time, does this affect our ability to obtain quality sleep?

We see this all the time in professional ball players, where games are played in the evening and extend into night time. By the time media obligations are done, it’s easily midnight or later before they get home or to the team hotel.

Thus, it’s interesting that sport scientists from the NBA Philadelphia 76ers teamed up with Liverpool John Moores U in the UK to compare the effects of hard intensity training and endurance training in the evenings on sleep quality and heart rate variability (Thomas et al. 2019). Here’s the basic setup of the study, published in the European Journal of Applied Physiology:
• Eight 18-40 year old endurance-trained runners (VO2peak 57 mL/kg/min; best 10 km time 38:06 average) took part in the study. None were night shift workers, were on any sleep medications, nor had travelled across time zones within the prior month.

• 3.5 h before bedtime, the runners performed: 1) 6x5 min @90% VO2peak with 6x5 min @60% VO2peak recovery (HIGH); 2) 60 min @45% VO2peak (LOW); and 3) no exercise (CON).

• Sleep quality was measured using polysomnography, wristwatch activity sensors, and a subjective sleep quality scale.

• Autonomic activity of the cardiovascular system was measured with a 2-lead electrode and heart rate variability (HRV) calculated.

• Each trial, participants arrived in the lab at 1750h, performed the exercise or control, had a standardized shower (duration, water temperature), and ate a standardized snack with free access to water. Sleep monitoring prep began at 1945 h, device use was banned, and sleep time commenced at 2230h.



Wake Up!
I found the study nicely designed with good experimental controls. Besides the standardized post-exercise routine, the bed and bedclothes, along with ambient temperature, were all standardized. Of course, the act of being monitored and sleeping in a different bed are unusual, but there was a familiarization night and this same stress would be present in all trials.

What were the key findings?
• The HIGH exercise was definitely harder, with an average speed of 15.8 km/h, max HR of 176/149 bpm during the on/off intervals, and a RPE of 18 (6-20 scale). In contrast, the LOW exercise values were 7.9 km/h, 114 bpm, and 11, respectively.

• Total time in bed was similar across all 3 conditions. However, total time asleep was higher in HIGH (477 min) and LOW (479 min) compared to CON (463 min). This was matched by lower time awake with HIGH and LOW than with CON.

• Furthermore, sleep onset time for each of the different stages of sleep were similar across all three conditions, and subjective sleep quality were similar.

• HIGH exercise led to a higher (50 bpm) average nightly HR than with either LOW (47 bpm) or CON (47 bpm). No differences was found in heart rate variability.



Summary
One thing not recorded in this study was whether the participants tended towards being morning or night time types. Also, all reported familiarity with evening activity. Finally, 3.5 h between the end of exercise and the start of bed time is still a fairly significant gap.

Given the above caveats, the takeaways from this study appears to be that we shouldn’t necessarily fear or worry about exercise in the evening detracting from getting a good night’s sleep. If anything, it might be a benefit in improving sleep quality. Furthermore, we don’t seem to need to adjust our training away from hard exercise if we are training in the evening.

Sleep well, ride fast and have fun!

References
Thomas C, Jones H, Whitworth-Turner C, Louis J (2019) High-intensity exercise in the evening does not disrupt sleep in endurance runners. Eur J Appl Physiol. https://doi.org/10.1007/s00421-019-04280-w



About Stephen:
Stephen Cheung is a Professor at Brock University, and has published over 120 scientific articles and book chapters dealing with the effects of thermal and hypoxic stress on human physiology and performance. He was recently included in a list of the 100,000 most-cited scientists internationally across all fields of research. Stephen’s book “Cycling Science” with Dr. Mikel Zabala from the Movistar Pro Cycling Team has hit the bookshelves, following up Cutting-Edge Cycling written with Hunter Allen.

Stephen can be reached for comments at [email protected] .

 


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