Latest News & Research: 29 January 2019

This week: Exercise pre-surgery can aid recovery • Fasting strengthens daily rhythms • Quick bouts of stair climbs boost health

Quick bouts of stair climbs boost health

A few minutes of stair climbing, at short intervals throughout the day, can improve cardiovascular health, according to new research from kinesiologists at McMaster University and UBC Okanagan, published in the journal Applied Physiology, Nutrition and Metabolism.

‘The findings make it even easier for people to incorporate ‘exercise snacks’ into their day’ said senior study author Martin Gibala, a professor of kinesiology at McMaster; ‘Those who work in office towers or live in apartment buildings can vigorously climb a few flights of stairs in the morning, at lunch, and in the evening and know they are getting an effective workout.’

Previous studies have shown that brief bouts of vigorous exercise, or sprint interval training (SIT), are effective when performed as a single session, with a few minutes of recovery between the intense bursts, requiring a total time commitment of 10 minutes or so.

For this study, researchers set out to determine if SIT exercise snacks, or vigorous bouts of stairclimbing performed as single sprints spread throughout the day would be sufficient to improve cardiorespiratory fitness (CRF).

One group of sedentary young adults vigorously climbed a three-flight stairwell, three times per day, separated by one to four hours of recovery. They repeated the protocol three times each week over the course of six weeks. The researchers compared the change in their fitness to a control group which did not exercise.

‘We know that sprint interval training works, but we were a bit surprised to see that the stair snacking approach was also effective’ said study co-author Jonathan Little, assistant professor at UBC’s Okanagan campus; ‘Vigorously climbing a few flights of stairs on your coffee or bathroom break during the day seems to be enough to boost fitness in people who are otherwise sedentary.’

In addition to being more fit, the stair climbers were also stronger compared to their sedentary counterparts at the end of the study, and generated more power during a maximal cycling test.

Source: McMaster University

Fasting strengthens daily rhythms

A study investigating why intermittent fasting can have health and fat loss benefits has found that circadian rhythms are key.

Scientists at the University of California investigated the impact of fasting on the circadian clock, with a particular focus on how fasting influences circadian rhythms in the liver and skeletal muscles.

The study, published in Cell Reports, involved mice adhering to 24-hour periods of fasting, the scientists measured various physiological functions. They saw that while fasting, mice used less oxygen and energy. However, as soon as the mice ate, these gene-driven physiological changes were reversed. This mirrors what researchers have previously seen in humans.

Explaining the study findings, lead study author Professor Paolo Sassone-Corsi said, ‘We discovered [that] fasting influences the circadian clock and fasting-driven cellular responses, which together work to achieve fasting-specific temporal gene regulation.’

He also noted that it influenced different tissue types to different degrees.

Sassone-Corsi concluded: ‘Fasting is able to essentially reprogram a variety of cellular responses. Therefore, optimal fasting in a timed manner would be strategic to positively affect cellular functions, ultimately benefitting health and protecting against ageing-associated diseases.’

Source: Medical News Today

Exercise pre-surgery can aid recovery

Exercise can protect both muscle and nerves from damage caused by the restoration of blood flow after injury or surgery, according to new research.

Zhen Yan, PhD, an expert on the cellular benefits of exercise, and his team from the University of Virginia in the US are working to better understand how the body is damaged by the restoration of blood flow – known as ischemia reperfusion injury – and to find ways to improve outcomes for people who suffer it, including surgery and trauma patients and soldiers injured on the battlefield. Their new finding shows that pre-injury exercise has substantial benefits in terms of preserving both muscle and nerve.

‘Exercise-trained mice had a much better recovery, evidenced by less nerve damage, less muscle damage and less reduction of contractile function [in the muscle] immediately after injury and days later,’ explained Yan, the director of the Center for Skeletal Muscle Research at the university's Robert M. Berne Cardiovascular Research Center.

Yan and his team used a ‘reporter gene’ he developed called the MitoTimer to understand the effects of reperfusion injury on muscle and nerves. The reporter gene allowed them to measure the amount of ‘oxidative stress’ to mitochondria (the cells’ powerhouses) when blood flow was restored.

They found that pre-injury exercise clearly reduced the damage to both muscle and nerve, but it did not significantly reduce the amount of oxidative stress. ‘We know exercise made the muscle and nerve tougher’ Yan said; ‘The protection is very clear.’

Source: University of Virginia