Thirty minutes exercise is enough to start losing weight

If weight loss is your goal, you may have been discouraged by the amount of exercise you might need to commit to in order to make a meaningful difference. It’s the sort if thing that can put you off your workout altogether if you’re not careful. Not any more. This research seems to indicate that 30 minutes of exercise is just as effective as 60 minutes in promoting weight loss.

In a sample of 60 heavy – but healthy – men over 13 weeks, half the group were set to exercise for 60 minutes a day wearing a heart rate monitor and a calorie counter, whereas the half of the group only exercised for 30 minutes per day. Both halves of the group had to exercise enough to raise a sweat.

On average, those who exercised for 30 minutes per day lost 3.6kg over the 13 weeks – the average weight loss in the 60 minutes per day exercise group was 2.7kg. Actual fat mass was reduced by similar amounts for both groups – approximately 4kg. A bonus for the 30 minute a day group was that they seemed to burn more calories than expected for the training programme that was set for them. Another key factor was that there did not seem to be any statistically significant changes found in energy intake or non-exercise physical activity that could explain the different responses between the 30 mins v 60 mins exercise per day groups.

A few explanations were put forward by the Danish researchers, though we can’t be certain about any of them. Amongst them, they suggest that perhaps 30 minutes of exercise felt so ‘doable’ that the participants had energy left over to start exercising more intensely within their 30 minute allocation per day.

A feature of this research is that it focuses on a group of moderately but not severely overweight men – a group that now makes up 40% of the Danish male population. It certainly adds data to the general evidence that 30 minutes of aerobic exercise on most days – even if you break that up into smaller chunks – is a worthwhile and beneficial goal to set yourself.

Midlife is not too late to start exercising and reaping the benefits

An encouraging study led by Dr Mark Hamer at my old College – University College London – suggests that it is never too late to start exercising and accrue the protective benefits against heart problems. In a study of over 4000 men and women with an average age of 49 years from the Whitehall II cohort study, their research showed that those who had been exercising regularly seemed to show lower markers of inflammation in their blood assays over 10 years of follow-up. This is important, because inflammation in the body tends to increase as we get older, and this inflammation has been identified as a risk in developing heart disease. As well as confirming the well-known link between exercise and improved heart health, this study seems to be the first to identify the anti-inflammatory effects of exercise as the possible mediating mechanism for these benefits.

The good news in this study is that the level of exercise needed to receive these protective benefits didn’t seem to be all that taxing. A mere 2.5 hours of moderate activity was all that was required to show the associated reduction in inflammatory markers. That means, you don’t have to be chained to a treadmill at the gym – brisk walks that raise a sweat count, as do activities such as gardening and mowing the lawn etc. Aim for around 120 beats per minute or slightly higher. However, its worth noting that people who stuck to their exercise plan for the full 10 years seemed to get the most benefit. Commitment to exercise as a lifestyle still seems to be the best route to wellbeing.

Some caution is still needed in interpreting the results of the study. The research relies upon people reporting their own levels of physical activity, and we tend to over-report this when asked. And the study also looked more at heart problems rather than heart disease itself. I’d be tempted to say that more research is needed, but there are other views on that. Anyway, my view is these findings are a great launchpad to take action.

So, whatever your age, if you’ve been inspired by the Olympics to become more physically active and to step up your exercise, here’s another good reason to do so. Remember though, if you haven’t been so physically active in a while, take things slow and steady. That way, your muscles, heart and lungs can get used to working a bit harder, you won’t feel so bad in the day or two following exercise, and you’ll be much more likely to feel like giving it another go in the following days, weeks and months.

Have fun!

How taking a break can help you fend off heart disease

When I wrote last week that I was taking a break, foremost in my mind was my birthday. I was trying to practice a little self-compassion, recognizing that posting each weekday was becoming a little more of a challenge than I can handle right now, while trying to balance other commitments to myself and others. The freshness I feel after a few days away means that I think it will be good to me to aim to blog 2-3 times a week instead. I think that helps me to strike a more workable balance.

However, there is another way in which breaks can prove very beneficial: small physical activity breaks when engaged in long spells of desk work. More specifically, light or moderate bouts of walking can help to protect you against the risk of heart disease and diabetes through inactivity. Overweight or obese people who walked for just 2 minutes after a period of uninterrupted sitting for two hours and drinking a standardized test drink lowered their post-consumptions glucose and insulin levels.

It is important to note that the participants were only studied over one day, but the potential is enormous. This really simple intervention looks like it can reduce sugar spikes and potentially add to the evidence base for a public health and clinical intervention strategy for reducing cardiovascular risk.

The really interesting finding from the study was the lack of any large difference between those who did light or more vigorous exercise. This points to the more damaging effects of sitting down all day without any kind of activity.

Just getting up and walking for 2 minutes every 20 minutes. That’s how easy it could be to ward off the damaging effects of remaining on our butts for long periods of time. That should be inspiration enough to get us all on our feet.

Tips for getting through that difficult run

If you are trying to extend out the time or distance that you are running, it can be tricky to break through some limits. You might be running a bit too quickly for the distance you are trying to accomplish. The speed makes a difference – it changes the proportion of fuel you draw from in your body from either carbohydrate or fat sources. A greater proportion of fat sources tend to be drawn from if you run relatively slowly and for periods of 25-30 minutes or more. Quicker, shorter runs tend to draw from your carb stores – which tends to be glycogen.

If you are having trouble breaking through a barrier, try out these three tips:

1. Try some self-talk. If you’re running alone and struggling, give yourself a bit of self-coaching. Tell yourself that you’re mentally fatigues — not physically tired, and that you can push through it. Trying telling yourself things like, “I’ll have some water in five minutes — that will make me feel better.” If you’re extending distance and doing your longest run ever, remind yourself how great you’ll feel when you’re finished.
2. Break up your run into smaller goals. Dividing up your run into smaller chunks will make the distance feel much more manageable. For example, if you’re running 20 km, think, “OK, it’s four 5-km runs.” At the start of each new chunk, visualize yourself just starting out on a new run with fresh legs and attitude and just focus on getting to the end of that section. This works for shorter distances too, and can work on the fly. You can focus on maintaining good form to get to the end of that street, and then focus on speed between those two lampposts.
3. Remember: It’s not always easy. As you’re doing a long run – maybe your weekly long, slow distance run, remind yourself that it’s not so easy to train for a long-distance event. If it were, everyone would be doing it, right? Remind yourself that you’re taking on a challenge and the difficulties you face will make your achievements all the more worthwhile in the end.

Keep getting out there!

The benefits of disconnecting every now and again

I’m a fine one to talk. I am one of the most connected people I know, and I know that I sometimes need to moderate my usage. Here’s why.

In a study presented at the Association for Computing Machinery’s Computer-Human Interaction Conference last week, researchers described how heart rate monitors were attached to computer users in a suburban office setting, while software sensors detected how often they switched windows. People who read email changed screens twice as often and were in a steady “high alert” state, with more constant heart rates. Those removed from email for five days experienced more natural, variable heart rates.

Five days – that’s how long it took to get participants’ heart rate variability to a more naturally occurring state. This is important: other research has shown that people with steady “high alert” heart rates have more cortisol, a hormone linked to stress. Stress on the job, in turn, has been linked to a variety of health problems.

It also seems that when you remove email, people multitask less (although multitasking doesn’t really exist – you actually rapidly switch between tasks), and they experience less stress. Those people who had no email reported that they were more able to do their jobs, stay on task, and experienced fewer time wasting interruptions. And it seems like objective behavioral measurements supported these reports. People with email switched windows an average of 37 times per hour. Those without changed screens half as often – about 18 times in an hour

Participants were happier too, even though it took some convincing for them to take part in the study. They reportedly loved being without email, especially if their manager supported it. The only downside was that people felt somewhat isolated without their email – though they managed to get critical information form those around them who did have email.

So, what can you do to help?

• Email vacations seem like a good idea – if you can still get the information you need
• Perhaps batching your email is a good idea too – turn off that email alert pop-up and sound that means you are tempted to switch screen to check email
• Designate times during the day when you’ll deal with your inbox
• And every now and again, it seems like a good idea to disconnect completely – perhaps an email vacation while still on the job.
• Managers take note – it’s also a good way to take care of your team.

Audio link for The Runners Round Table, episode 124

We did the podcast last night and it was great fun, though I was a bit jet-lagged. We ended up focusing on three topics:

• Do statins degrade muscle performance and / or increase perceived pain on exercise?
• Do you need a multivitamin if you eat a healthy diet?
• And sudden deaths during marathons – should I be worried?

You can find the audio file here, and you can follow all the contributors on twitter:

• @sarb
• @runninglam
• @drjohnm
• And our host, @drdavemd

Enjoy!