Kilojoule burn in heat vs cold

A pram camper finished her outdoors workout on a warm Spring morning, with a pointed question: "do you burn more calories (or kilojoules) working out on a warm day compared to a cold one?"
"Hmmm, I replied, that's a tricky question." And here's why.

• Cold weather itself doesn't increase kilojoule needs. BUT your body does use a lot of energy to warm and humidify the air you breathe when exercising outside in the cold. According to sport nutritionist and author, Nancy Clark, if you were to burn 600 calories (equivalent to about 2,500 kilojoules) while cross-country skiing for an hour in zero degree weather, you may use an estimated 23 percent of those calories to warm the inspired air. But you use the heat you generate with exercise to warm the air you breathe and help stop your lungs from getting chilled. 

• You don't burn extra kilojoules in cold weather unless your body temperature drops and you start to shiver. And even then, what you may 'burn' depends on a number of different factors. When a person is shivering, the body needs to work harder to maintain body temperature). And studies have shown that shivering can burn about 400 calories (or 1680 kilojoules) per hour and it depletes glycogen stores and leaves you feeling tired. In this situation the energy expenditure in cold weather is greater than in warm weather, but the actual amount of additional calories burned due to shivering depends on the temperature, how long the person was exposed, and the type of clothing. (And considering that at pram camp you're not likely to be wearing a lot of layers or even shivering for much more than a few minutes, the extra 'burn' would probably be non-existent).
  
• If you sweat more, particularly during your workouts in summer, you won't burn extra kilojoules.You burn kilojoules when your muscles perform work. Sweating is just the way your body uses to regulate excess heat.
  
  
  

Tweaking workouts to burn more fat

Some comebacks (like leg warmers) should stay in the past. But your return to exercise, whether it's after a having a baby, or after any long lay-off (including hibernation over winter), is different.

Any break in a regular exercise routine, including after giving birth, can result in a loss of lean muscle mass and cardio strength. Once you do start to ease yourself back into regular exercise, over time you can also start to tweak your workouts to burn more fat. Here's how:

...while walking
Walk your regular route the opposite direction, so your body doesn't know what to expect.

...while running
Typically run for 30 minutes? Try this: day 1 - go slower than usual, but jog for 40 mins. Day 2 - speed up, but jog for only 20 mins. Day 3 - jog fast for 1 min, easy for 2, repeat 6-10 times.

...don't run but want to start?
While out walking add short bursts of running into your routine - run to the next tree or lamppost and walk (recover) for two lamp posts. Repeat 4-6 times. Build on this walking session each week so eventually you're doing more running than walking.

...while resistance or weights training
Stand instead of sitting to use more muscles

...while cycling
Sit when you climb. When you stand, you use body weight for momentum; sitting mean you have to push more weight with less help.

And check out our tip sheet on your number one fat loss solution - interval training - to give your workout an extra boost

Top hero foods for new Mums

Most of us know what we should eat and why we should eat it. But it's often the case we get caught up in work, or running around after our little (or not so little) kids, that we don't. We say it's too hard too eat healthily, we don't have time to cook or plan meals, or even that it costs more to prepare healthy alternatives. And we look for a short-cut or what we think will be a quick fix to good health and fat loss.

And does it work? Maybe in the short term, but so-called 'dieting' isn't the answer when you look at the big picture. Diets mess with your head, your moods, and confidence. How often do you feel guilty about something you ate for instance? 

Diets can create a negative cycle of stress, deprivation, bingeing, guilt, denial, frustration and the biggie – failure. Not exactly what you'd call a great model for a happy, healthy Mum. And like it or not, our kids learn by example and not just from what we say but what we do. A friend of mine was shocked to see her three-year-old mimic her on the bathroom scales, saying she'd “have to try harder” and that she was “too fat”.

So forget dieting – start by throwing away all the junk magazines and crazy diet books – and start eating positively and getting savvy about nutrition. It all comes down to habits and behaviour.

After all, if you take the time now to look at why you're eating certain foods - and looking at the foods that seem to sabotage your health – then you can set yourself up with new, positive, life-long eating habits.

And more importantly, happy, healthy Mums can't help but be an example to their kids.

New Mums - check out our top 12 hero foods especially for you! You need to take extra care of your body so it has a chance to recover and heal from the birth trauma!