No Need To Cool Down After Exercise?

Athletes, coaches and physical education teachers have always been told that an active cool down is more effective for promoting post exercise recovery than a passive cool down (no activity). This is assumed to allow for individuals to perform better during subsequent training sessions or competition and perhaps even lower the risk of injury. 

However, there is not much research on whether the above is true. I've written previously how it may be unnecessary to cool down after exercise. What if I say that in some cases an active cool down may even be harmful?

The most widely used post recovery exercise intervention is probably the active cool down. It is commonly referred to as the 'warm down'. This is usually a 5 to 15 minutes of low to moderate intensity exercises after exercise/ competition. Some will do a slow jog, cyclists often ride easy on the bike while it's attached to a stationary trainer.

The following review by Van Hooren and Peake (2018) compares the effects of various types of active cool downs with passive cool downs on sports performance, injuries, long term adaptive responses and markers of post exercise recovery.

Ready for the summary? 

The review shows that an active cool down helps lead to faster removal of lactate in blood. However the practical relevance of this finding is questionable since lactate is not necessarily removed faster from muscles. 

An active cool down can partially prevent the depression of circulating immune cell counts after exercise, although it is unknown if this leads to fewer infections and illnesses.

An active cool down can definitely result in a faster recovery of the cardiovascular and respiratory system after exercise/ competition, but it remains unknown if this reduces post exercise fainting and cardiovascular complications.

Active cool downs does NOT significantly reduce delayed onset of muscle soreness (DOMs) or improve the recovery of indirect markers of muscle damage. It does not significantly alter the recovery of neuromuscular and contractile properties of muscles, it does not improve range of motion of muscles, and does not reduce musculotendinous stiffness following exercise. It may even interfere with glycogen synthesis.

The review also provided evidence that an active cool down generally does not improve and may even negatively affect performance if the time between successive training sessions or competition is > 4 hours.

An active cool down also has no substantial effects on next day(s) sports performance although some beneficial effects have been reported. They do not prevent injuries and preliminary evidence suggests that performing regular cool downs do not reduce the long term adaptive response.

However, most individuals perceive an active cool down as being more beneficial than a passive cool down. The effectiveness of an active cool down may differ depending on each individual's preferences and beliefs. Some athletes may benefit more from an active cool down while others may prefer to perform no cool down at all.

Some general guidelines for those who still wish to perform an active cool down. It should involve aerobic activities performed at low to moderate intensities to increase blood flow, but prevent development of substantial additional fatigue. 

It should involve low to moderate impact to prevent additional muscular damage or DOMs. It should be shorter than 30 minutes to prevent substantial interference with glycogen resynthesis. So make sure you eat/ drink quickly after exercise or competition. 

Some evidence also suggest that an active cool down should involve the same muscles used in the preceding activity. Now you know.

Reference

Van Hooren B, Peake JM (2018). DO We Need A Cool-Down After Exercise? A Narrative Review Of The Psychophysiological Effects And The Effects On Performance, Injuries And The Long-Term Adaptive Response. Sports Med. 48:1575-1595. DOI: 10.1007/s40279-018-0916-2

Cycling Helps Prevent Dementia?

Riding towards the sun

My laptop could not connect to the hotel WIFI network last weekend when I was away, so I'm only posting last week's post now.

Many of you reading this will know that on the Saturdays that I'm not traveling, I do a long bike ride with my usual cycling group. Since I was away, I also missed my Saturday bike ride.

I may have missed my Saturday ride, but I did get to read a very interesting article on cycling. Researchers found that sustained aerobic exercises (like cycling) may reduce the risk of dementia (Hou et al, 2025).

There were 479, 723 participants ( 260,730 females, 54.4 percent) with a mean age of 56.5 years in that study. These data were collected from the UK Biobank with the aim to investigate the long-term association between travel modes and dementia risk and to evaluate whether genetic predisposition can modify the association between travel modes and dementia risk.

To understand the link between brain health and common forms of travel, the participants were asked if they usually used motor vehicles, walking, cycling or public transport.

The researchers found that participants that cycled regularly (not including commuting to work) had a lower risk of developing dementia compared to those who walked, drove or used public transport. They were 19 percent less likely to develop all-cause dementia and 22 percent less likely to develop Alzheimer's disease.

The authors suggest that "this likely stems from cycling's higher aerobic intensity and cognitive engagement (e.g. navigation, coordination), which may enhance neuroplasticity more than walking alone". Other than regular exposure to fresh air from cycling, the physical demands of cycling plus the need to stay alert whilst on the roads or trails may help to maintain brain health.

This is supported by other studies (Erickson et al, 2011) where cycling or other aerobic exercises causes the hippocampus, the part of the brain responsible for memory formation, learning and spatial navigation to grow. Note that typically, the hippocampus reduces in size during late adulthood (from the mid to late 60's).

The authors concluded that the findings "suggest that promoting active travel strategies, particularly cycling, may be associated with lower dementia risk among middle-aged and older adults, which carries substantial public health benefits".

Now, that's a very good reason to keep cycling. Let's make our roads safer for cycling.

References

Erickson KI, Voss MW, Prakash RS et al (2011). Exercise Training Increases Size Of Hippocampus And improves Momory. ProNatl Acad Sci USA. 10897): 3017-3022. DOI: 10.1073/pnas.1015950108

Hou C, Zhang Y, Zhao F et al (2025). Active Travel Mode And Incident Dementia And Brain Structure. JAMA Netw Open. 8(6): e2514316. DOI: jamanetworkopen.2025.14316

Time Of The Day When You Are At Your Best

Picture from Healthyplace.com

I have been out of school for decades and have not sat for any tests or exams in quite a while. But I do see new patients almost every day I am working in our clinics. I do take plenty of "tests" too, since every single patient I see will evaluate my treatment and decide if I made them better.

You must be wondering why I am writing about tests this week, Well, the Singapore primary school leaving exams (PSLE) just ended this past week.  Parents whose children just sat for the exams must heave a collective sigh of relief now that it's all over. 

The typical start times for the PSLE oral exams are at 0800 while written exams generally commence at 0815 hours. That's definitely an early start for those taking exams.

Unlike the students sitting for exams, we usually see new patients in our clinic whenever we can fit them in for an appointment. This may not necessarily be the best according to a group of researchers who analyzed the results of over 100,000 oral exams. They found a clear Gaussian distribution (also know as the Normal distribution or bell curve) in pass rates that peaked at noon. 

Passing rate by hour 

Between 11 am and 1 pm is the best time (pictured above). Any earlier or later the chances of passing significantly decreased. In fact the earlier or later in the day these students took a test, the less likely they were to pass.

The reason being our cognitive (or conscious intellectual ability) performance improves over the course of the morning and then declines in the afternoon. We also may have declining energy levels later in the afternoon. If your exam is scheduled later in the day, you may also stress about it and this usually leads to poorer performance.

According to the author's, the examiner's cognitive performance and fatigue level also matters. Both the examiner and student will be at their peak level of performance during the mid day hours.

This all means that whenever possible if you have to take a test or exam, an important meeting or a job interview, you should schedule it between 11 am and 1 pm. It can be the difference between passing and failing. 

Perhaps we should only see new patients in our clinics between 11 am and 1 pm then. 

Reference

Vicario CM, Nitsche MA, Lucifora C et al (2025). Timing Matters! Academic Assessment Changes Throughout The Day. Frontiers Psychol. 16:1605041. DOI: 10.3389/fpsyg.1605041