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The Beginners Guide To Fartlek Training

16th April 2021

16th April 2021

By Shivraj Bassi

Looking for a way to spice up your cardio routines?

If it wasn’t obvious, we at Innermost love cardio exercise techniques such as skippingrunning, walking and rowing. Not only for their health benefits such as improved cardiovascular health and increased endurance, but also for the general feel-good factor these workouts provide. However, switching up your workouts every now and then can be a great way to prevent stagnation and keep routines that little bit more exciting.

Case in point Fartlek training

Fartlek training is a great way to bring some variety to your cardio routines, enabling greater flexibility in your routine, and train your muscles.

What is the fartlek training method?

Swedish for “speed play”, Fartlek training refers to a technique used in cardio exercise that consists of varying your time and pace.

The aim of this training exercise is to improve your endurance, stamina and overall fitness levels, by switching up the intensity of your workout in short bursts. Fartlek training also keeps your workout interesting as no 2 exercises will be the same. This could involve switching between walking and running for a set amount of time to get your body used to different levels of aerobic and anaerobic endurance.

How you measure these intervals, the distance, the location, it’s entirely up to you. That’s the unique draw about Fartlek; it’s unpredictable, erratic and random.

Fartlek vs interval training

With this in mind, you might be thinking  ‘this sounds the same as interval training’. And yes, while the 2 share a focus on aerobic and anaerobic fitness, there are some key differences make each form of cardio training unique. Ultimately, the best method depends on individual preferences, goals, and fitness levels.

Fartlek training

Fartlek training involves alternating periods of intense effort with changing recovery lengths, often following a natural terrain like a park or forest as opposed to a treadmill or running circuit. This makes it more unstructured, unpredictable and spontaneous – 1 minute may be a light jog, the next 30 seconds an uphill run, and the next 30 a full-out sprint.

Interval training

Interval training on the other hand, is more structured, with specific intervals of high-intensity work followed by predetermined rest periods. Think 1 minute rest, 1-minute sprint. This allows for better control and progression but lacks the variability of fartlek training that keeps a workout interesting.

What are the benefits of fartlek training?

There are a wealth of benefits involved in the integration of Fartlek training in your routine. From the flexibility of the technique all the way to the science behind the Swedish strategy, we’ve listed some of the main Fartlek benefits that you need to know below...

Improves Your Mental Health

    The benefits of exercise on your mental well-being are indisputable and so the benefits of Fartlek training integration will have a hugely positive impact on your overall health. It also aids in keeping a workout varied, helping to lower the mental fatigue that can come with rigid cardio exercises.

    Extremely Versatile And Less Structured

      Speaking of which - many people hate interval training due to the rigid structure. On the flip side, with one of the Fartlek benefits is that you can do this training whenever, wherever – at home, in the gym and outside. It’s also not limited to running – give it a go with whatever your favourite exercise type is!

      Improves Speed and Endurance

        Unlike interval training, with Fartlek training, you do not stop. This means continuous running, with the aim of conditioning your body to adapt to different speeds. Over time, this means you will be able to run faster for longer, with improved energy and performance levels.

        A study within the International Journal of Physical Education, Fitness and Sports specifically looked at the benefits of Fartlek training for endurance, comparing a control group of those partaking in Fartlek exercises to those that were not.

        Here the study concluded that there was a “significant difference on cardiorespiratory endurance, breathe holding time, and resting pulse rate” among those within the fartlek control group.

        For this reason, many runners use it in the upcoming training for marathons and extended distances – so if you’re currently in training, give Fartlek a go.

        Mix It Up

          If you’re struggling to maintain motivation to engage in cardio and Fartlek training – they key is to mix it up. Engage in different cardio activities: running, swimming, cycling and skipping are all great for toning up and losing weight.

          Builds Muscle

          Fartlek can also be a valuable tool for muscle growth as alternating between these intense bursts of exercise recovery can increase growth hormone production, improve cardiovascular health, and enhance metabolic rate. When combined with resistance training and a balanced diet, fartlek can contribute to muscle gain and overall fitness.

          Is fartlek training good for beginners?

          Like most cardio workouts, fartlek exercises are perfect for beginners as they can be fully tailored to an individual's fitness levels and abilities. They are also a good choice for those looking to realise and improve upon their endurance speed and stamina limits without being overwhelmed by the intensity of HIIT.

          What are the best fartlek routines?

          If you’re interested in trying to add the Fartlek techniques into your workout routines but are a bit stuck with where to start, remember to always warm up adequately and warm down as best as possible to avoid injury, and pair any exercise with a healthy diet and lifestyle choices to get the best results.

          The combinations are endless, but to get you inspired, here are three examples below. Don’t push yourself too much to begin with, though – slow and steady wins the race.

          Free fartlek

          For a free fartlek, start with a warm up and gradually increase your pace when you feel comfortable. As you feel comfortable, increase your pace. After a mile or two, or perhaps a 10 minute interval, increase again. Remember this is your work out – if you need to walk, walk!

          You could also introduce power surges into your routine, where you push yourself to your fastest pace at one minute intervals.

          Landmark fartlek

          The landmark fartlek is a great way of keeping your workout unique and interesting.

          To do this, warm up for around 10 minutes and pick any landmark you see in the distance (anything from a bus stop to a shop). Then sprint to it at a high-intensity speed. Once you reach it, slow back down and search for the next. Rinse and repeat to your heart's content.

          The 5 4 3 2 1 fartlek

          On the other side of the scale, the 5-4-3-2-1 fartlek offers a more structured run whilst maintaining the interval flexibility of the workout. As the name suggests, here you run for 5 minutes followed by a 2:30 minute rest – this then drops by a minute and 30 seconds respectively until you hit the final 1-minute sprint.

          How can I ‘time’ my fartlek training?

          When it comes to timings, this is one of the ways that you can get really creative with Fartlek training. If you want to keep it simple, of course, you can just use a stop watch – maybe through your smart phone or watch. However, many people use more unique techniques to time their Fartlek intervals to ensure that they aren’t getting bored.

          Use Your Playlist

          A great and interactive way to time your Fartlek interviews is through your playlist. Every time the song changes, change pace or exercise to ensure you are regularly switching up your exercise routine and really getting the most out of the training technique.

          Use Television Advertisements

          If you’re lucky enough to have a treadmill set up at home, or even if your gym has a TV set up, get yourself in front of the TV and start your workout during a television programme. Every time an advert comes on, switch it up! Change pace, exercise, incline – you name it. This is a great way to time your Fartlek intervals and you can distract yourself from the struggles of cardio with your favourite binge-worthy Netflix episodes.

          Use Distances 

          This one is ideal for racers. If you’re in training for an upcoming race and want to challenge yourself with your pace for different elements of the race, you can map out your route to make sure you’re mixing up your pace intermittently.

          For long distance, a great way to do this is to change pace every 400m – but it’s up to you!

          Innermost Top Tips

          • As with any exercise tactic, make sure not to overdo it. You need to mix up your workouts – their intensity, duration and technique, to ensure that your body doesn’t become complacent.
          • Don’t partake in Fartlek training for too long at a time. The optimum duration for a workout like this is between 45 and 60 minutes, depending on your fitness level.
          • Involve your friends! This is the perfect workout to do as a group.

          So, we’d say that the Fartlek benefits are pretty solid. For other tips to improve your cardio workouts, up your endurance or increase your energy levels, visit our blog.

          References:

          • NHS. (2021). Benefits of Exercise. Retrieved 8 April 2021.Click here.
          • The Lost Art of Fartlek. (2021). Retrieved 9 April 2021.Click here.
          • Elamaran, M., (2014). Effect of Fartlek Training on Selected Physiological Parameters among College Male Athletes, 3(4): 77-83. Click here.
          • Kumar, P., (2015). Effect of fartlek training for developing endurance ability among athletes, 2(2): 291-293. Click here.

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          Magnesium for Sleep: Here's What You Need to Know
            Sleep is one of the most important parts of the day. Feeling well, training well and moving through the day with enough energy to actually enjoy it, all rely on a good night’s sleep. Yet for many of us, it is also one of the first things to suffer when life gets busy. Late nights. Early starts. Stress. Screens. Training sessions squeezed into already full days. A mind that seems to become suddenly very active the moment your head hits the pillow. It is no surprise, then, that magnesium has become one of the most talked-about supplements for sleep. It is often linked with relaxation, recovery and the ability to switch off at night. But as with most things in wellness, the real answer is a little more nuanced than “take this and sleep better”. So, does research suggest that magnesium helps with sleep? And how do you know whether it is right for you? Let’s take a closer look. Key takeaways Magnesium supports several normal processes linked with rest, including muscle function, nervous system function and energy metabolism. Magnesium may help some people sleep better, particularly where poor sleep is connected to stress, low magnesium intake, muscle tension or poor recovery. Food should always be the foundation, but magnesium supplements can help support a consistent intake when busy lifestyles, training and irregular meals get in the way. Magnesium works best as part of a broader evening routine, alongside sensible caffeine timing, reduced evening stimulation, good nutrition and proper recovery. What is magnesium and why is it linked to sleep Magnesium is an essential mineral found in food, water and supplements that is involved in over 300 bodily processes. It acts as a mandatory helper molecule (coenzyme) for your cells. Some of the key biological functions of magnesium include: Supports energy production by helping the body convert food into usable cellular energy. Contributes to normal muscle function, including the balance between muscle contraction and relaxation. Supports normal nervous system function by helping regulate nerve signalling and neurotransmitter activity. Contributes to normal bone structure, with a significant proportion of the body’s magnesium stored in bone. Supports normal glucose metabolism, with magnesium involved in blood glucose control and insulin-related processes. While by no means an exhaustive list, this gives a wider sense of how widely it is used throughout the body. Magnesium’s connection with sleep comes from the way it supports systems involved in relaxation and recovery. As highlighted, magnesium helps regulate nerve signalling and muscle contraction, which is one reason it is often associated with calmness, reduced tension and post-training recovery. It is also commonly discussed in relation to GABA (or gamma-aminobutyric acid), a neurotransmitter involved in calming nervous system activity. While the relationship between magnesium and sleep is still being studied, the general theory is that healthy magnesium levels may help the body and brain shift away from a heightened, alert state and towards a more relaxed one. This matters because good sleep rarely begins the moment you get into bed. It starts earlier, as your body and mind begin to downshift. For active, busy people, this can be one of the hardest parts of the day. If your evening routine looks like finishing work, replying to messages, doing a late workout, eating quickly and then expecting your brain to instantly power down, you are asking a lot from your body. Magnesium may support the relaxation side of that process, but it works best when the rest of your routine is helping too. Does magnesium help you sleep? Magnesium may help some people sleep better, but it is not a guaranteed solution for everyone. Its value sits more in supporting the body’s normal relaxation and recovery processes than acting like a direct sleep aid. A 2021 systematic review and meta-analysis published in BMC Complementary Medicine and Therapies looked at oral magnesium supplementation for insomnia in older adults. It found that magnesium may help reduce the time it takes to fall asleep. While the results were promising, the sample size was limited. Magnesium is most likely to be helpful when poor sleep is linked to factors such as low magnesium intake, stress, muscle tension, a busy nervous system or poor recovery. Someone who trains several times a week, works long days and struggles to wind down at night may find it more beneficial for sleep specifically than someone whose sleep issue is caused by an untreated medical condition, severe anxiety, chronic insomnia or an inconsistent sleep schedule. It is also worth remembering that “better sleep” can mean different things to different people. Some people want to fall asleep faster. Others wake up during the night. Some sleep for eight hours but still wake feeling flat.  Magnesium is usually discussed in relation to relaxation and sleep onset, rather than acting as a powerful sleep aid that forces deeper or longer sleep. A helpful way to think about it is this: magnesium supports the conditions that may make good sleep more likely. It does not replace the foundations of sleep itself (many of which we have discussed before). Can You Get Magnesium from Food? Yes, and this is a good place to start. Magnesium is found in a range of everyday foods, including: leafy green vegetables, nuts, seeds, legumes, wholegrains and dark chocolate. Pumpkin seeds, almonds, spinach, black beans and wholegrain products are all useful sources. Food Why it helps Pumpkin seeds Naturally rich in magnesium and easy to add to meals or snacks Almonds and cashews Useful sources of magnesium, healthy fats and plant-based protein Spinach and leafy greens Provide magnesium alongside fibre and other micronutrients Black beans and lentils Support magnesium intake while also adding fibre and slow-release carbohydrates Wholegrains A practical everyday source of magnesium and sustained energy Dark chocolate Contains magnesium, although best enjoyed as part of a balanced diet   A food-first approach also supports the bigger picture. Your body does not experience nutrients in isolation. A diet rich in magnesium-containing foods is often also higher in fibre, plant compounds and other micronutrients that support overall wellbeing. That said, busy lives do not always make consistent nutrition easy. Active people may also pay closer attention to magnesium because of its role in muscle function, energy metabolism and recovery. If you train regularly, sweat heavily, experience muscle tension or find yourself relying on convenience meals during busy weeks, your magnesium intake may be worth looking at. This is where effective supplementation can help, especially when it forms part of a wider routine rather than replacing a balanced diet. Where magnesium supplements can help Food should always be the foundation, but supplements can make magnesium intake easier to manage when life is busy. Rather than trying to rebuild your diet overnight, the right supplement can help you add consistent support around the routines you already have: morning training, post-workout recovery, evening wind-downs, or busy workdays where meals are not always as balanced as you would like. With Innermost, magnesium is included as part of wider, goal-led formulations rather than as a standalone quick fix. The Fit Protein contains 250mg of magnesium per serving, alongside vegan protein, maca, rhodiola root, cocomineral and Pink Himalayan sea salt, making it well suited to active lifestyles where performance, energy and recovery all matter. The Strong Protein contains 200mg of magnesium per serving, alongside protein, casein, creatine monohydrate, Montmorency cherries and bilberries. This makes magnesium part of a broader strength and recovery blend, supporting people who train regularly and want their nutrition to work harder around their goals. For evening recovery, The Recover Capsules are another good supplementation option, with magnesium included as part of a wider recovery-focused formula. This makes them a natural fit for people who want to support recovery at the end of the day, particularly when sleep, training and overall performance are closely connected. When should you take magnesium for sleep? Magnesium works best when it becomes part of a routine you can actually stick to. Because magnesium supports relaxation and recovery rather than acting as a sedative, timing does not need to be overly complicated. The most effective approach is usually the one you can repeat consistently. For many people, magnesium fits naturally into the evening. That might mean taking it with dinner, after training, or as part of a wider wind-down routine before bed. The aim is not to wait until you feel wired and then expect magnesium to force sleep. It is to give your body steady support at the point in the day when you want to start slowing down. This is particularly relevant if your days are busy or training-focused. When your body has been under physical or mental demand, sleep is part of the recovery process. Magnesium can support that bigger picture by contributing to normal muscle function, nervous system function and energy metabolism. Final thoughts: magnesium, sleep and recovery Magnesium has earned its place in the sleep conversation, but it deserves to be understood properly. It is an essential mineral with important roles in muscle function, nervous system function and recovery. For some people, particularly those who are active, stressed, low in magnesium-rich foods or struggling to wind down at night, supplementation may be a useful addition to an evening routine. The key is to keep expectations realistic. Magnesium is not a shortcut to perfect sleep. It is a supportive tool that works best alongside consistent habits: sensible caffeine timing, less evening stimulation, good nutrition, proper recovery and a calm bedtime routine. For Innermost, the bigger point is that form matters, but formulation matters too. Magnesium works best when it fits into a wider routine. That might mean supporting your intake through a recovery-focused product, taking supplements with food, and using them consistently rather than expecting an instant effect. References  Magnesium. National Institute for Health Professionals. Click here. Jewett, E., Sharma, S (2023). Physiology, GABA. National Library of Medicine. Click here. Mah, J., Pitre, T (2021).Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis. BMC Complementary Medicine and Therapies. Click here. Read more
          Fibre
          Within the fitness space there can be a tendency to think of fibre as something that’s just functional. Important, of course, but often its impact is only framed around digestion. In reality, fibre plays a far broader role in how your body performs and how you feel day to day, influencing variables like energy stability and appetite regulation through to long-term metabolic health. For anyone already investing in their training, recovery, and overall wellbeing, a high fibre diet matters more than you might think. It’s one of the simplest ways to bring more consistency to your nutrition, without adding complexity. In this guide, we’ll take a closer look at what fibre does, why it matters, and how to build a high fibre diet in a way that fits naturally into your routine. What is fibre and why it matters Fibre is a type of carbohydrate that is naturally sourced from foods like wholegrains, beans, nuts and more. At its core, dietary fibre is the part of plant foods your body can’t fully digest. Rather than being absorbed, it moves through the digestive system, interacting with everything along the way. This process is what makes fibre so valuable. It slows digestion, supports beneficial gut bacteria, and helps regulate how nutrients enter the bloodstream. Over time, these effects compound, influencing energy levels, hunger signals, and metabolic health. It’s worth understanding that fibre isn’t one single thing, and while it is often grouped together, different types have different roles. Broadly, fibre falls into two categories: Soluble fibre: This dissolves in water and forms a gel-like substance, helping to slow digestion and regulate blood sugar and cholesterol. Insoluble fibre: This adds bulk and supports regular movement through the digestive system. Most whole foods contain a combination of both, which is why variety matters more than focusing on a single source. Why intake is often lower than expected You might read this and think you’re easily hitting your daily fibre requirements. Yet, even among people who eat relatively well, fibre intake tends to fall short. In the UK, the recommendation sits at around 30g per day, yet average intake is closer to 18–20g. This isn’t usually down to poor habits. More often, it reflects modern eating patterns: A strong focus on high-protein meals can reduce the variety of plant foods in a diet, lowering fibre intake over time. A reliance on staples like white bread and pasta contain less fibre than wholegrain alternatives, making fibre intake harder to reach. Quick, convenient meals often lack the whole ingredients needed to support adequate fibre intake. The result isn’t a complete absence of fibre, but it does lead to a gradual shortfall below the 30g recommendations. Each meal might seem balanced in isolation, but across a full day or week, intake consistently sits below where it needs to be. The Key Benefits of a High Fibre Diet  A high fibre diet supports several key areas of health at the same time: Gut health and microbiome support As previously mentioned, fibre’s most recognised role is in digestion, but its impact actually goes deeper than that. Certain fibres act as prebiotics, feeding beneficial gut bacteria. These bacteria produce compounds known as short-chain fatty acids (SCFAs), including butyrate, which plays a role in maintaining the integrity of the gut lining and regulating inflammation. A 2019 review published in The Lancet found that higher dietary fibre intake was consistently associated with improved gut health markers and reduced risk of several chronic conditions. The key takeaway wasn’t a single “superfood”, but the cumulative effect of consistent fibre intake over time. There’s also increasing interest in how microbiome diversity influences overall health. A more varied intake of fibre tends to support a more diverse gut environment, which is linked to better resilience and function. For those looking to improve their training routines and hit new PBs, a well-functioning gut is central to recovery. This is because fibre supports the gut environment, which in turn affects how efficiently nutrients are absorbed. More stable energy levels When it comes to your energy, it isn’t just about calorie intake. It’s also key to ensure your body can effectively process these calories. This is where fibre can be highly beneficial. This is because fibre slows the digestion of other carbohydrates, leading to a more gradual release of glucose into the bloodstream. This helps avoid the sharp spikes and dips that can come from highly refined meals. Studies also show that diets higher in fibre are associated with improved glycaemic control, even in otherwise healthy individuals. In practical terms, this often leads to: More consistent energy across the day Fewer mid-afternoon crashes Reduced reliance on quick fixes like sugar or caffeine For those balancing work, training, and recovery, the more stable blood sugar levels provided by fibre mean more consistent energy availability. This can translate into better training sessions, particularly for longer or more demanding workouts. Appetite regulation High fibre foods tend to be more filling due to their volume and slower digestion. At the same time, they influence hormones involved in hunger and fullness, including ghrelin and peptide YY. There’s also a hormonal aspect to this. Fibre-rich foods can influence the release of satiety hormones, helping your body better recognise when it’s full. This creates a more sustainable approach to body composition. Instead of relying on weight loss restriction, your diet supports appetite regulation more naturally. Heart Health and Long-Term Outcomes In addition to the shorter-term health and wellness benefits, fibre intake also has a beneficial impact on long-term health. Soluble fibre, in particular, has been shown to help reduce LDL cholesterol by binding to cholesterol in the digestive system and aiding its removal. Large cohort studies have consistently linked higher fibre intake with a reduced risk of cardiovascular disease and type 2 diabetes. This is partly due to improved blood sugar regulation and partly due to the broader metabolic benefits of a fibre-rich diet. One study in particular by the BMJ found that each additional 7g of fibre per day was associated with a 9% reduction in cardiovascular disease risk. These outcomes aren’t immediate, but they reinforce the role of fibre as a long-term investment in health. High Fibre Diet Foods We’ve written about his previously (see here for our guide on high fibre foods) but in short, building a high fibre lifestyle doesn’t require a complete overhaul of your current diet. It’s instead about increasing variety and making more intentional choices within your existing routine. Below we have outlined some key foods that can help increase fibre intake. Whole grains Oats, brown rice, quinoa, and wholegrain bread provide a steady source of fibre while supporting sustained energy. They’re an easy upgrade from refined grains and tend to be more filling. Fruits and vegetables Eating more fruit and vegetable is one of the simplest ways to raise fibre intake. A useful approach is to focus on variety: Berries and apples for convenience Leafy greens for micronutrient density Root vegetables for more substantial meals Legumes Lentils, chickpeas, and beans are among the most fibre-dense foods available. They also provide plant-based protein, making them particularly useful in meals focused on satiety and recovery. Nuts and Seeds Chia seeds, flaxseeds, and almonds offer a concentrated source of fibre and can be added easily to meals. Even small additions, such as a tablespoon of seeds in a breakfast or smoothie, can make a difference over time. A Smarter Way to Think About Fibre Fibre doesn’t need to be treated as a standalone goal. It works best as part of a balanced, well-structured approach to nutrition - one that supports how you feel day to day, not just how you perform in the odd moment. For most people, that starts with whole foods. Building meals around plant variety, whole grains, and consistent habits. From there, the role of supplementation becomes more effective. The Innermost approach reflects that balance. Products like The Greens Blend can help support daily plant intake and micronutrients, while products such as The Lean Protein fit alongside a diet that prioritises both protein and fibre, rather than one at the expense of the other. Building a high fibre diet isn’t about adding or overhauling, instead It’s about making those small adjustments that bring more consistency to your routine. Over time, those shifts tend to have the biggest impact - not just on digestion, but on how your body feels, performs, and recovers. References Renolds, A., Mann, J., Cummings, J., Winter, N., MDiet, E., Morenga, L. (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet. 393 (10170), 434-445. Click here.  NHS UK. How to get more fibre into your diet. Click here.  Hullings, A., Sinha, R., Liao, L., Freedman, N., Graubard, B., Loftfield, E. (2020). Whole grain and dietary fiber intake and risk of colorectal cancer in the NIH-AARP Diet and Health Study cohort. The American Journal of Clinical Nutrition. 112 (3), 603-612. Click here. Threapleton, D., Greenwood, D., Evans, C., Cleghorn, C., Nykjaer, C., Woodhead, C., Cade, J., Gale, C., Burley, V. (2013). Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ.347. Click here. Read more