‘Weekend warriors’ workout tied to longevity with low risk for CVD, cancer and all-cause mortality.

Courtesy: Pixabay

The standard recommendation by CDC[1] and American Heart Association[2] is 150 minutes of moderate or 75 minutes of vigorous physical activity per week for achieving health benefits for those aged 18 to 64 years. But, very few people can keep up with this routine and most of us just cram the workout of entire week into 1- 2 weekend sessions, 2-3 long runs or participating in our favorite sports like hiking, basketball or Zumba.

Courtesy: Pixabay

Well, although not ideal but, it reduces your risk of dying from cardiovascular, all cause and cancer by 30% according to a new study published in JAMA Internal Medicine online on January 9, 2017.[3] The study was conducted by researchers from the National Centre for Sport and Exercise Medicine–East Midlands at Loughborough University in the United Kingdom.

This study examined whether ‘weekend warriors’ also derive the same benefits as their more active, regularly hitting the gym counterparts.

Gary O’Donovan did a pooled analysis of 63 591 adult respondents (>40 years old) who answered a household based survey in England and Scotland. The survey was conducted between 1994 to 2012 and analyzed in 2016. The survey was prospectively linked to British National Health Service Central Registry which identified participants who died, including the cause of death.

For the purpose of analysis, the respondents very divided into 4 groups depending on their exercise pattern:  Those who  were inactive (reporting no moderate- or vigorous-intensity activities), insufficiently active (reporting <150 min/wk in moderate-intensity and <75 min/wk in vigorous-intensity activities), weekend warrior (reporting ≥150 min/wk in moderate-intensity or ≥75 min/wk in vigorous-intensity activities from 1 or 2 sessions), and regularly active (reporting ≥150 min/wk in moderate-intensity or ≥75 min/wk in vigorous-intensity activities from ≥3 sessions). 

The mean age of the study participants was 58.6 years with nearly equal gender ratio. About 40,000 people did not exercise at all, 14000 were insufficiently active, 2500 were weekend warriors and 7000 people were regularly active.

During the follow up period of 9 years, 8,800 people died, CVD being responsible for 2780 and cancer for 2500 deaths.

A detailed analysis of ‘weekend warriors’ group showed that, men were more likely to work vigorously on weekends, mostly engaging in some sort of sports. Walking briskly was also very popular and reported by 30% of weekend warriors. Weekend warriors spent a total of 300 minutes exercising as compared to 450 minutes spent by those who are regular.

After adjustment for all confounders, as compared to inactive participants risk of all cause death for weekend warriors was 30% less (hazard ratio [HR], 0.70), risk of CVD was 40%( HR=0.60) less and cancer death was 18% less (HR= 0.82).

Similar pattern of risk reduction was found in insufficiently active people too, indicating any exercise is better than being totally inactive.

When analysis was run between inactive group and regular exercise group, the regularly active persons have a 35% decrease in all-cause mortality (HR=0.65),  41% lower CVD death(HR=0.59), and 21% lower cancer death(HR=0.79).

During the follow up period of 9 years, 8,800 people died, CVD being responsible for 2780 and cancer for 2500 deaths.

"These findings suggest that some physical activity in an isolated session, or low activity, is certainly better than no activity for reducing mortality risk," Hannah Arem and Loretta DiPietro, of George Washington University, wrote in a commentary accompanying the new study in the journal.

The study has its own limitations that it is dependent on self-reporting and assessed the activity level only once at the start of the study. The study also did not assess the risk of injury in the weekend warriors.

But, the encouraging new conclusion emerging from the study is for those who exercise less frequently is even 1-2 vigorous activity session per week have health benefits and can lower the mortality.

The recommendations by CDC for regular physical activity can be found here.

The recommendations by American Heart Association ( AHA)  for regular physical activity can be found here.

---

[1] https://www.cdc.gov/physicalactivity/basics/adults/

[2] http://www.heart.org/HEARTORG/HealthyLiving/PhysicalActivity/FitnessBasics/American-Heart-Association-Recommendations-for-Physical-Activity-in-Adults_UCM_307976_Article.jsp#.WIPgqBsrK00

[3] http://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2596007

Moderate intensity physical activity for an hour mitigates the risk of death associated with sedentary lifestyle: A Meta-analysis.

Clinical Pearls:

• Intense to moderate physical activity for 60-75 minutes’ can eliminate the effects of prolonged sitting (> 8 hours).
• This equals to brisk walking at 5.6 km/h or cycling for pleasure at 16 km/h.

The association of sedentary lifestyle and many chronic conditions and colorectal cancer is well known and physical inactivity is an important modifiable risk factors in the causation of many chronic condition.  Prolonged sitting is one of the important cause of premature mortality.

But, according to a Meta-analysis involving about a million people, intense to moderate physical activity for 60-75 minutes’ can undermine the effects of prolonged sitting. This study was published online in the Lancet on July 27, 2016.[1] Examples of physical activity were brisk walking at 5.6 km/h or cycling for pleasure at 16 km/h.

This is a second in the series of articles published on physical inactivity by Lancet, the first was published in 2012, sending a message that physical inactivity is a global pandemic killer-responsible for 5.3 million premature deaths worldwide. The number equals the deaths caused by smoking and twice the deaths caused by obesity.

This is the first harmonized meta-analysis that compares the relationship between all-cause mortality and sedentary life style and different levels of physical inactivity.

A systematic review of literature identified about 16 studies out of which 13 were identified by the researchers as providing data on sitting time and all-cause mortality.

The combined study data generated data on pool of 1,005,791 individuals from different countries, who were followed up for 2-18 years.

The study participants were divided into quartiles according to the time spent being physically active and ranged from less than 5 minutes/day to 60-75 minutes/day. The daily sitting and TV viewing time was also divided into 4 standardized protocol.

It was seen that those who very active (60-75 minutes/day), the amount of sitting time does not increase the mortality. But, the risk of death increases as the activity time decreases. WHO guidelines also recommends at least 150 minutes of physical activity per week, which is far less than what the study recommends.[2]

"A clear dose-response association was observed, with an almost curvilinear augmented risk for all-cause mortality with increased sitting time in combination with lower levels of activity," the researchers noted.

For the purpose of estimating the hazard ratio(HR), the most active individuals were used as the reference group. (HR=1).

People who exercised the least (less than 5 min/day) were at highest risk, even if they did not spend much time sitting (less than 4 h/day). In this group the hazard of premature death was 1.27. This was way higher than those group of individuals who were most active physically (60-75 min/day) but also spent more than 8 hours sitting (HR=1.04). This was very close to the referent group, which led the researchers to conclude that physical inactivity is the root cause of premature deaths, independent of the hours of sitting.

The findings of this study emphasized the importance of physical activity, even if you have a job that demands prolonged sitting.

The study also draws attention towards relationship with TV watching and premature death. Watching TV for more than 3 hours per day is associated with premature death regardless of physical activity except in the most active quartile. In this group the mortality was only increased if you watch more than 5 hours of TV. The benefit of physical activity is not very strong in people watching TV because of “residual confounding”. Dr. Ekelund points that perhaps these people have unhealthy life- style that include snacking or drinking that increases the risks.

Ekelund pointed out in a London press conference [3]  that the average amount of time adults in the United Kingdom spend watching TV is three hours and six minutes. “I don’t know if it’s too much to ask that maybe a little of those three hours be devoted to physical activity,” he said. The general rule of thumb, as Ekelund succinctly advised: “Sit less and move more, and the more the better.”

He also emphasized the message about "moving more," suggesting that people should walk as much as they can and that if they do need to sit for prolonged periods, they should break up those periods with short bursts of activity, such as walking for 5 minutes every hour.

The full Lancet podcast about the series can be heard here.

---

[1] http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)30370-1/fulltext

[2]  http://www.who.int/dietphysicalactivity/factsheet_recommendations/en/

[3] http://press.thelancet.com/PhysicalactivityMEDIA.mp3