At this time of year, many of us set ourselves resolutions to lose weight. This might be to boost our power-to-weight and therefore sharpen our performance, to stave off middle age’s creeping effects on the scales, or just to slim down after a little hard-earned festive overindulgence. The science of weight loss is an amazingly noisy field, and it is clear that there are a number of methods people have successfully used to drop pounds. In this blog, we cannot possibly cover the entirety of the science on how best to chip away at excess body fat mass. What we will cover, though, is a recent and excellent study published by researchers from the University of Bath in the UK that examined the effects of intermittent fasting on weight loss and body composition. Specifically, in the study the researchers sought to quantify the effects of intermittent fasting on weight loss and body composition that are independent of effects on energy balance – i.e. does intermittent fasting...

by Dr Dan Plews

As we have discussed in several previous blogs, and in our courses, adaptations to endurance training are produced through activation of cellular signalling pathways in response to individual training sessions, with these cellular signalling pathways activated through detection of the physiological stresses generated through exercise. In this blog, we are going to focus on one of the most well-known proteins in the adaptive signalling cascade, the cellular energy sensor AMPK.

AMPK, or to give its full name, 5’adenosine monophosphate-activated protein kinase, is an important protein in the detection of the cellular energy stresses generated during endurance exercise (1). Specifically, AMPK within the muscle is activated by the metabolic stresses generated by exercise, and subsequently activates signalling pathways associated with endurance training adaptation (2). This pathway makes a lot of sense; if our muscle is stressed by exercise, we detect it and then...

As many of you will know, the application of heart rate variability (HRV) to endurance training is one of my major research interests (6–8), and something I consistently integrate into my coaching practice with elite and amateur triathletes. Daily measurements of HRV upon waking to tell us about our autonomic function; specifically, HRV measured as the square root of the mean squared difference between beat-to-beat intervals (rMSSD) is a measure of parasympathetic nervous system activity. The parasympathetic nervous system is the arm of the autonomic system that slows things like your heart rate down, and therefore suppressed parasympathetic activity, and so suppressed HRV measured as rMSSD, is indicative of a state of stress. This is what makes daily HRV measurements useful for informing the training process; trends in HRV can help us to determine when we might need to back off, and when we can be confident in putting the hammer down. Indeed, using HRV measurements to guide...

As the 2021 triathlon season finishes, there are many short course ITU triathletes who are looking to turn their hand to the longer course Ironman triathlon. What’s the carrot? To win the infamous Ironman World Championships (normally) held in Kona Hawaii. Many of these athletes are boasted to have huge engines, and VO2max values, sometimes close to 90 ml.kg.min! But does this really translate to success over the longer distance, particularly in the heat?

The physiological characteristics that define outstanding endurance running performance, particularly in the marathon, have been the subject of considerable research (7–9, 12). The standard models used to explain performance with impressive accuracy in endurance events include three main profiling variables: the maximum rate oxygen can be taken up and consumed (VO2max) (2); the percentage of VO2max that can be sustained, the so-called ‘performance VO2’ that is closely linked to the maximum metabolic...

By Dr Dan Plews 

The act of grounding has undoubtedly become popular recently, at least in the circles I move in. But what is it? Grounding, also called earthing, involves doing activities that “ground” or electrically reconnect you to the Earth. This depends on earthing science and grounding physics to explain how electrical charges from the Earth can positively affect your body.

The Earth’s surface has free electrons (and speculatively); contact with the Earth’s surface may allow electron migration into the body. The electrons can act as antioxidants and neutralise reactive oxygen species (ROS). As I have discussed in the past, ROS accumulates in muscle during high-intensity exercise. ROS appears to have a fatiguing effect on muscle, possibly through effects on calcium handling processes that are critical in muscle contraction (3). Antioxidants help ‘mop up ROS in muscle; so, if we have more antioxidants, we are more able to manage the ROS that...

As readers of our blog and those who have done our courses will know, applied exercise physiologists working with endurance athletes can non-invasively measure what is called the peak fat oxidation rate – PFO for short – during routine profiling assessments. The PFO is the highest rate of fat oxidation measured during an incremental exercise test; that is, an exercise test in which the intensity is progressively increased from very light to maximal. The PFO is thought to give us some insight into the individual athlete’s capacity for fat oxidation during exercise (1, 7).

That makes a lot of sense in theory. However, in practical terms how PFO as a profiling characteristic can be interpreted is still relatively poorly understood. A series of studies performed over the last 15 years or so have identified markers in skeletal muscle that are associated with PFO, including fibre type profile, mitochondrial characteristics, and the abundance or activity of a range of...

We all know that being strong on the bike is critical to the success of any long-distance triathlete. But how do we train for it? In this short blog, we’ll briefly describe the main session types when training for the cycling leg of long-distance triathlon. For much more detail, check out our courses; LDT 102 on training programme fundamentals and LDT 104 on training monitoring.

At EndureIQ, we promote a three-phase model of training planning for Ironman triathlon; a general preparation phase, specific strength phase, and competition phase. In the general preparation phase, our goal is to build a strong aerobic base by accumulating a large overall training volume, whilst also increasing our maximum aerobic capacity with a small number of targeted, high-intensity interval training sessions. We, therefore, aim for a highly polarised overall training intensity distribution, where the vast majority (~85-90%) of our training time is accumulated below the lactate threshold, with...

We all know that the pre-competition taper is one of the fundamental components of the build-up to an endurance event. In this short blog, we will briefly cover some of the science behind the purpose of, and best practices in, tapering. We cover the science and practice of the pre-competition taper in much more detail in LDT102, our course on training programme fundamentals.

 Why do we need to taper?

In order to optimise your taper, it is important to first understand what a taper is trying to achieve. Tapering has been defined as the deliberate reduction in training load in the days prior to competition (4), the purpose of which is to provide the athlete with sufficient rest and recovery to perform at their best, but without reversing the adaptations gained through training (6). Tapering is therefore a balancing act between providing rest and recovery and preventing detraining.

Crucially, tapering has been shown across a number of investigations to be beneficial to endurance...

As we have discussed at length in the past, some of the fundamental physiological adaptations sought by endurance athletes through training occur in the mitochondria. A textbook will tell you that the mitochondria are the ‘aerobic powerhouses’ of cells; the sites of aerobic metabolism, and therefore metabolically where an endurance athlete makes their money. It has long been known that significant mitochondrial remodelling occurs in response to exercise (4), with increased size, number, and functionality of mitochondria observed following endurance training (5). This mitochondrial remodelling, and subsequent useful increase in the mitochondrial respiratory capacity, typically occurs as a result of mitochondrial biogenesis – the building of nice new mitochondria – and mitophagy – the break-down of damaged existing mitochondria.

A couple of recent studies have reported quite startling findings; namely, that short periods of very intense training actually...