icon-account icon-glass

Popular Products

The Lean Protein
Whey protein powder for weight-loss.
The Energy Booster
Pre/intra-workout powder with BCAAs.

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.

          Product Spotlight

          Need Expert Advice?

          Other Insights

          Halal Collagen Cover Image
          Collagen has become a staple in many modern wellness routines, used to support everything from skin health to recovery and joint function. But as its popularity has grown, so too has the need for greater clarity around what’s in these products - and how they’re made. Case in point - halal collagen. Unlike other supplement ingredients, collagen is typically derived from animal sources. This makes its suitability under halal dietary guidelines less straightforward. Two collagen powders may look almost identical on the surface, yet differ significantly in how they are sourced, processed, and certified, meaning that one might be halal compliant and the other not so much. For anyone looking to incorporate collagen supplements into their routine, understanding these differences matters. This guide breaks down what exactly makes collagen halal and non halal, where confusion often comes in, and how to choose a supplement that aligns with both your values and your expectations for quality. What is halal collagen? Halal collagen refers to collagen that has been produced in accordance with Islamic dietary laws. While the term “halal” is often associated with food, the same principles apply to supplements, including collagen powders and capsules. In practice, this means that halal collagen must meet specific criteria across its entire lifecycle - not just in its final ingredient form. What makes collagen halal certified? Determining whether collagen is halal goes far beyond scanning an ingredient label. Collagen itself is most sourced from bovine (cow) or marine (fish) origins. Whether either is considered halal depends not only on the source, but on how it has been handled from extraction through to final production. Halal sourcing The sourcing of collagen is the first step to halal certification. Firstly, for a collagen product to be halal it must be sourced from a halal permissible animal such as cattle (bovine collagen) or fish (marine collagen). For bovine collagen, animals must be raised and slaughtered according to halal principles and Islamic rites collectively known as Zabiha. This includes: Invocation of Allah's name (Tasmiyyah) at the moment of slaughter. A swift cut to the throat to ensure humane treatment. Slaughtering conducted by a sane adult Muslim. The animal must also be healthy at the time of slaughter. Without the above considerations, collagen supplements cannot be considered permissible, regardless of quality. Halal processing Processing is the next critical factor in halal collagen certification. Collagen extraction often involves enzymes or chemical treatments to isolate and refine the protein. This hydrolysis process often uses enzymes to break down collagen into peptides. These enzymes must be plant-based (e.g., papain) or sourced from halal-certified animals; porcine-derived enzymes (like porcine trypsin) are forbidden. If any of these substances are derived from non-halal sources, the integrity of the product is compromised. Any solvents or processing aids used during extraction must also be free from ethanol or other non-halal alcohols. Halal collagen certification also ensures that no prohibited additives, such as non-halal gelatine carriers or animal-based anti-caking agents, were introduced during the manufacturing process. Halal Manufacturing Manufacturing standards are also highly important in making collagen supplements halal certified. Even when ingredients are halal, shared facilities or inadequate controls can introduce cross-contamination. As such, the manufacturing of halal collagen must follow the below guidelines: Non cross contamination: certified products are produced under strict conditions that ensure separation from non-halal substances throughout production, storage, and packaging. Complete surface cleaning: If a facility handles both Halal and non-Halal products, a rigorous, religiously supervised deep cleaning (often called Samak or Taharah) must occur between runs. Auditors must verify that no "Najis" (unclean/prohibited) residues remain. Common Misconceptions About Halal Collagen As collagen has become more widely used, a number of assumptions have emerged around its suitability within a halal diet. These are some of the most common. Collagen is Halal be default: because collagen is a natural protein, it’s easy to assume it meets dietary requirements. In reality, its origin and processing determine whether it is permissible. Marine collagen is always halal: While often suitable, this still depends on how the collagen is produced and whether non-halal substances are introduced during processing. Hydrolysed collagen is always halal: As with other forms of collagen, halal permissibility depends entirely on its source and production. There is also a tendency to equate “clean” or “natural” products with halal compliance. While these qualities can overlap, they are not the same. A supplement may be free from additives and still not meet halal standards. Benefits of halal collagen When halal collagen is produced with quality and integrity in mind, it can support a range of wellness goals. While we’ve spoken about these before, however below are some of the key benefits of halal collagen: It plays a role in maintaining skin structure and elasticity. Supports joint function and contributes to recovery following physical activity. They form part of a broader approach to looking, feeling, and performing at their best. These benefits are closely linked to how the collagen is sourced and formulated. Products that prioritise transparency, clean processing, and effective formats - such as hydrolysed collagen peptides - are more likely to deliver consistent results. For those seeking halal collagen supplements, this alignment between quality and compliance becomes key. How to choose a halal collagen supplement? Choosing a halal collagen powder or supplement should feel straightforward, but in practice it often requires a closer look. Below are some of the key things you should look for when purchasing halal collagen supplements: Certification is the most reliable starting point. A recognised halal certification confirms that the product has been assessed across sourcing, processing, and manufacturing. Clear information about where the collagen is sourced and how it is produced can indicate a more considered approach to formulation. The type of collagen also matters. Hydrolysed collagen peptides are widely used because they integrate easily into daily routines and are readily utilised by the body. The overall experience of the product. Taste, mixability, and ease of use all contribute to whether a supplement becomes part of a consistent routine - which is ultimately where results are seen. Is Innermost halal? In short, yes. Innermost products are halal certified, meaning they meet strict standards across sourcing, processing, and production. This ensures that every stage of development aligns with halal requirements. Innermost’s The Glow Blend contains high quality halal certified hydrolysed bovine collagen peptides and is formulated to support your skin and overall wellbeing, with extra nutrients like hyaluronic acid, vitamin C, biotin and folate. Alongside certification, our Innermost proteins and supplements focuses on clean, effective formulations designed to support real results. We prioritise ingredient quality, avoid unnecessary additives, and create products that fit seamlessly into everyday routines. If you’re looking for a collagen supplement that aligns with both your nutritional goals and your values, explore the Innermost range to find a halal-certified option that fits seamlessly into your routine. References Permadi, S., Ujilestari, T., Hakim, L et al. Characteristics and Applications of Collagen from the Animal By-Product as a Potential Source for Food Ingredients. Permadi et al. Reviews in Agricultural Science. 2024, 327-346. Click here. Aslan., H. The influence of halal awareness, halal certificate, subjective norms, perceived behavioral control, attitude and trust on purchase intention of culinary products among Muslim costumers in Turkey. International Journal of Gastronomy and Food Science. 2023. Click here. Schmidt, M. M. et al. Collagen extraction process. International Food Research Journal. 2016. Click here. Read more
          The Ingredient We Almost Didn't Put In The Energy Booster
          There's a question we ask about every ingredient before it goes into a product. Not "is this trending?" Not "does it look good on the label?" Just: does the evidence actually support putting this in? Most of the time, that question is straightforward. Either the research is there or it isn't. But occasionally you land on an ingredient where the science says yes and something else gives you pause. That's where formulation gets genuinely interesting. Beta alanine was one of those decisions. What Beta Alanine Actually Does Most people who've taken a pre-workout have felt beta alanine without knowing it. It's the ingredient responsible for the tingling sensation you get in your face, your neck, your hands. That feeling has a name: paraesthesia. It's harmless. But it's also the reason we nearly left beta alanine out. Before I get to that, the science. Beta alanine is a non-essential amino acid. On its own, it doesn't do very much. But inside muscle tissue, it binds with another amino acid called histidine to form something called carnosine. And carnosine is where the real work happens. During intense exercise, your muscles produce hydrogen ions as a byproduct of energy production. It's the build-up of those hydrogen ions, not lactic acid as most people think, that causes the burning sensation and the drop-off in performance. Carnosine acts as a buffer. It mops up those hydrogen ions and delays the point at which fatigue kicks in. The research on this is substantial. A 2012 meta-analysis published in the journal Amino Acids, covering over 40 studies, found that beta alanine supplementation consistently improved exercise capacity, particularly in high-intensity efforts lasting between one and four minutes. The effect size was meaningful and reproducible. This wasn't a promising pilot study. It was a decade of accumulated evidence pointing in the same direction. In practical terms: more reps before failure. More output before you hit the wall. Sustained performance over a longer window. So why the hesitation? The decision we almost got wrong The tingling. Not because it's dangerous. It isn't. The paraesthesia from beta alanine is a well-understood pharmacological response and there is no evidence of harm at the doses used in supplementation. But we had a real concern: if someone takes The Workout Blend for the first time and feels an unexpected tingling in their face, and nobody told them it was coming, we've just lost their trust. Possibly permanently. The easy path was to leave it out. Plenty of pre-workout formulas do exactly that, either because they're being cautious or because they want a smoother consumer experience. No ingredient, no explanation required. We talked about it a lot. And the conclusion we kept coming back to was this: removing an ingredient with strong evidence because it might confuse people is not how we want to make formulation decisions. That's the same logic that leads brands to include ingredients with weak evidence because they're more familiar, more comfortable, more sellable. The answer wasn't to remove it. The answer was to be upfront about it. The tingling means the beta alanine is working. It's a real physiological response to a real ingredient doing a real thing. If we believe in the science, we include the ingredient and we explain what's happening. That felt like the right standard to hold ourselves to. What the rest of the market does Most pre-workout formulas fall into one of two categories.The first is the stimulant-heavy formula. Stacked with caffeine at doses that produce a short spike, a noticeable crash, and not much else underneath. These sell well because the immediate sensation of energy feels like evidence that something is working. It often isn't, not in any meaningful physiological sense beyond what caffeine alone would do. The second is the proprietary blend. A long list of ingredients with no disclosed amounts, making it impossible to know whether any of them are present at doses that match the research. Proprietary blends let brands list an ingredient without committing to a dose that would actually work. Both approaches optimise for perception. Neither optimises for performance. What I'd recommend The Energy Booster (soon to be renamed to The Workout Blend) contains beta alanine alongside citrulline malate, which supports nitric oxide production and blood flow during training, BCAAs at a 2:1:1 ratio to safeguard lean muscle, and natural caffeine from guarana for sustained energy without the spike you get from synthetic sources. The formulation is built around what the research supports at doses that match the evidence. If you feel the tingling the first time you take it, that's the beta alanine. It's normal, it fades within 20 minutes or so, and it's a sign the formula is doing what it's supposed to do. Read more