When you first start running, if you increase your mileage and speed steadily and give your body enough opportunity to recover, you’ll witness the minor miracle of just how amazing your body is at adapting to new stresses, and becoming stronger and leaner. That’s a very good thing. It helps you achieve paces and distances that at one point you didn’t think you’d ever be capable of. Better still, running at easier paces no longer causes sweat to spill down your face, your heart to pummel your ribcage or your lungs to feel at the point of explosion. And aside from being rather more comfortable, that feels like a huge victory. Which it is.

But adaptation does have a dark side for anyone who wants to ramp up weight loss. Once your body becomes more efficient at a certain distance or pace, your kilojoule burn starts to stall and even decline. ‘If all you do is run the same distance and terrain at the same effort day after day, you will adapt to that,’ says exercise physiologist and running coach Janet Hamilton, founder of Running Strong. The key to building your fitness – and to continue losing weight – is to keep adding intensity to your running routine.

Ramping up the intensity of your workouts, however, doesn’t mean you should run as fast as possible every single day. The cardiovascular system adapts to new stresses much faster than the muscles, bones and joints do. It’s important to balance tougher workouts with rest days and easy running so that your body has a chance to adapt and get stronger. It’s also important to have a variety of more-intense sessions to build full-body fitness.

By mixing up the type of sessions you do, you’re stimulating different parts of your physiology. Use the other days to recover with rest, easy running or low-impact cross-training (such as cycling, yoga or strength training), and you’ll build full-body fitness more effectively and without raising your risk of injury.

Each week, do at least two of the following workouts, designed by Hamilton. On the other days, rest, cross-train or run easy. Don’t do any of these workouts back to back, as that could lead to injury.

1. Tempo run

What it is: Sustaining a faster-than-usual pace without breaking into an all-out sprint.

Why it matters: Tempo work improves running efficiency so you can run faster over a longer distance with less effort.

What to do: Warm up with an easy kilometre and gradually speed up to your 10-K pace for one kilometre. Recover with three easy minutes and repeat twice more. Cool down with an easy kilometre.

How it feels: You should feel like you stepped just outside your comfort zone.

Keep it honest: Every two or three weeks, lengthen the tempo segment.

2. Hill Work

What it is: Any run that incorporates some ascents.

Why it matters: Hills – aka ‘speedwork in disguise’ – build leg and lung strength.

What to do: Once a week, incorporate into your run a variety of hills that take 30-60 seconds to climb. As you run uphill try to stay relaxed. Keep your gaze straight ahead and your shoulders down. Envision your feet pushing up and off the leg and the road rising to meet you. When you’re on the way down, land light and push off quickly – don’t let your feet slap the pavement. Also try to avoid leaning back and braking with your quads, which will put you at risk of injury.

How it feels: Try to maintain an even level of effort as you’re climbing the hill and as you’re descending. Avoid charging up the hill; you don’t want to be totally exhausted when you reach the top.

Keep it honest: As your fitness improves, add to the demands of the session by adding more challenging hills with a variety of gradients and lengths.

3. Speedwork

What it is: Sessions where you’re alternating between bouts of very hard running (at, say, 95 per cent of your maximum effort) and easy recovery. Lots of speedwork sessions revolve around running repeats at your 5-K pace, but you can also run shorter reps at faster paces with longer recovery intervals.

Why it matters: These challenging sessions will improve aerobic capacity and running economy, and help you turn your legs over faster.

What to do: Warm up with 10 minutes of walking, easy running and finally a few sets of strides. Then alternate between running at your 5-K pace for 400m and recovering with an easy 400m.

How it feels: During the bouts of hard work it should feel tough to say more than one or two words at a time. If you can recite the question ‘Am I running fast enough?’ without gasping, the answer is no. The goal is to have enough recovery to be able to do the next speed interval correctly. ‘Focus on matching your target pace, not beating it,’ says Hamilton.

Keep it honest: Start with 2 x 400m repeats, then move up to 4-6 x 400m repeats, alternating that with 400m of easy running to recover. Once you’re comfortable, start cutting the recovery intervals to 200m. If you want to switch things up, keep the recovery intervals at 400m but lengthen the bouts of hard work to 600-800m.

4. Long run

What it is: Any run that’s longer than your typical run.

Why it matters: Long runs build your aerobic foundations, endurance and mental strength. When you push your body further or longer than normal, you stimulate the production of more mitochondria (the energy powerhouses of your cells) and more capillaries (which carry oxygenated blood from the heart to your muscles), and you train your heart to pump blood more efficiently.

What to do: Start with a long run that’s about one-third of your total weekly mileage. So, in case you don’t have your abacus to hand, if you typically run 25 kilometres a week, start with an eight-kilometre long run. If you’re targeting a half marathon, you will ultimately want to be able to tackle an 18-kilometre long run to comfortably complete the race. If you have a time goal, your longest runs should be slightly longer than the race distance, 20-24 kilometres for a half marathon or 14-kilometres for a 10-K.

How it feels: Settle into a comfortable, conversational pace that you can sustain and finish still feeling strong. You should be able to chat, but if you can belt out an X Factor-worthy rendition of your favourite running tune, you need to pick up the pace.

Keep it honest: Add two to five kilometres every three weeks. ‘It’s helpful to hold your long run steady for a couple of weeks before you progress – you should feel you’ve ‘conquered’ the distance,’ says Hamilton.

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