The COVID-19 pandemic is (at the time of writing) currently wreaking havoc on the UK fitness industry, in early March 2020 gyms in England were forced to close with around six hours’ notice leaving recreational and professional athletes alike wondering how they could continue with their training and exercise routines. With a countrywide lockdown announced a few days later and no indication of how long it would last, there began a sudden rush to purchase fitness and exercise equipment and even for some gym owners to agree equipment loans to clients.

The benefits of exercise in general are universally accepted, and physical activity has also been demonstrated to be beneficial at improving the health conditions frequently associated with COVID-19 (1). With gyms closed and movement restricted, the only option for many gym-goers and athletes was to continue their exercise regime as best they could at home (2). This, however, was only the beginning of the problem. Not only did the cost of gym equipment suitable for home use skyrocket in price overnight but so did the cost of commercial equipment too, as people tried to get hold of what they could. With equipment also in short supply, many times trainees have been left with little or no equipment to work with. In most cases athletes and trainees who were used to having access to racks of dumbbells, bars, plates, and resistance machines in their gyms have been left with only a small collection of equipment at home, often significantly lighter than they would regularly use.

It is generally accepted that when undertaking a hypertrophy orientated programme, a repetition range of 6-12 repetitions (reps) per set, with 60-90 seconds inter-set rest should be utilised, along with a load that is sufficiently heavy enough to lead to (or almost to) volatile fatigue or concentric (technical) failure during some of the sets (3–5). Maintenance of strength and muscle hypertrophy is an important factor for the majority of gym attending populations, my members and clients included. As a gym owner and coach, what options have been available to me to help my clients and athletes continue their training outside of a formal gym setting, without compromising their results or goals?

Low load vs. high load

As a coach, when prescribing resistance exercises, external load selection is a key variable, with current guidelines suggesting 65%-85% of the trainee’s one-repetition maximum (1-RM) to be the ideal load for favourable increases in muscle hypertrophy (6,7). In my experience, for most trainees in a home environment with limited equipment during lockdown, this is simply not possible to achieve. A number of researchers have recently challenged the view that these high loads are required to elicit muscle hypertrophy (8). Some have suggested that low-load training may even produce greater results in type I muscle fibres (9). One solution worthy of consideration for home training is making use of the smaller weights trainees have available and use a low-load high-rep (LL) strategy, instead of the traditional high-load low-rep (HL) scheme. Although certainly not a new theory, the concept of LL verses HL has received some interest of late with new studies and new review papers very recently published (9–13). So, what does this latest literature tell us that may be of use?

Probably most importantly for us in the scope of this article, is that both LL and HL resistance training protocols, when performed to volatile failure can each elicit significant increases in muscle hypertrophy (9,12). Now as is common, authors will argue that many of the studies were carried out on untrained or recreational individuals. As it is accepted that individuals with less training experience will always exhibit superior levels of hypertrophy in comparison to those with previous experience. However, in contrast, studies on well-trained and older populations have also demonstrated similar increases in muscle hypertrophy using LL compared to HL (8–10,12). What that means for us, is that for home training regardless of training experience, exercising with small weights when performed to volatile fatigue can theoretically produce similar levels of muscle hypertrophy when compared to exercising in a gym environment using a traditional HL protocol.

Before we get carried away, many of the studies have used loads of around 40%-50% of the participants 1-RM as the low-load, with some even demonstrating positive results using 30% 1-RM (14,15). In my experience, the heaviest weight a typical home trainee may have during lockdown is perhaps a 16kg kettlebell. This is potentially good news for some isolation and upper body training, but for compound exercises such as squats, this is not going to be anything close to even 30% 1-RM, meaning we need another solution. Additionally, for strength athletes in particular, the use of LL compared to HL has not been shown to provide any significant increases in strength (12).

Time-under-tension

Another important, yet often underutilised variable in the prescription of resistance training, is the speed or tempo at which the participant executes the exercise (4). I first came across the concept of time-under-tension (TUT) in my early training days, from reading the works of the late Charles Poliquin some years prior to even becoming a coach. Poliquin maintained that TUT, or essentially the total amount of time that a muscle was under tension whilst performing a movement, was one of the most important variables for muscle hypertrophy (16,17). Now, Poliquin’s methods were largely developed from his own experience and in some cases the science to back them up can be scarce. Although there is little to no scientific evidence from the 80s and 90s to back up Poliquin’s claims, TUT has been the subject of some research in the last 5-10 years. 

The good news for us is, this research has confirmed that if we do extend the length of time that a muscle is under tension during an exercise movement, then this does indeed positively impact muscle hypertrophy (18–20). What is even better news for us with respect to this article, is that slowing down the eccentric contractions has been suggested to be superior for hypertrophy, when compared to standard heavy weight training (19). A ‘gold standard’ TUT repetition velocity of (4sec eccentric, 1sec pause, 2sec concentric) has been suggested (18,21). Although some coaches may argue that implementing TUT reduces the volume-load of an exercise (20), for trainees at home in lockdown with limited weights, this actually becomes an ideal scenario, particularly for compound exercises.

Blood-flow restriction

Blood-flow restriction (BFR) is a relatively new exercise strategy. Essentially it involves using a pneumatic tourniquet system to partially restrict arterial blood flow to the muscle being exercised, whilst fully restricting the venous outflow  (22). BFR has repeatedly been demonstrated to produce similar adaptations in terms of strength and muscle hypertrophy, with loads of around 30% of the participants 1-RM shown to be the ideal loading strategy (22,23). Until recently, due to cost and skill requirements, BFR was limited to sports science laboratories, professional sports, and rehabilitation settings. However, I have recently come across a growing number of vendors retailing personal use, cheap ‘BFR training bands’ aimed at recreational athletes. The problem with these, as I see it, is that professional quality BFR equipment automatically calculates, manages, and regulates the pressures the cuffs are inflated to. Whereas, these cheaper bands are literally that, an elastic tourniquet that you tighten around your arm or leg to restrict the blood flow. There are, however, some major issues with this. Firstly, it is not possible to calculate the correct pressure required to restrict the blood flow (this is a crucial variable when prescribing BFR). Secondly, as the bands are manually tightened, it would be impossible to provide a standard pressure to both limbs or repeat that pressure each training session, not to mention the various safety considerations that should be understood before applying BFR (22).

Although the concept of BFR with its use of 30% 1-RM loads producing similar results in hypertrophy and strength as traditional HL training does sound like a very appealing strategy for the home trainee, in my opinion this should be avoided. The only exception would be, if carried out under the supervision of an experienced practitioner using professional equipment. So, the question remains, what strategy would I employ with my clients and athletes?

My thoughts

IThe strategy that I found most effective with my clients and athletes throughout lockdown has been based upon a mix of LL high-reps (HR) and LL with TUT. I found that LL HR worked particularly well in smaller muscle groups, the upper-body musculature and with assistance exercises and LL with TUT to be more beneficial in larger compound movements such as squats and big pressing movements.

Although not scientifically measured, clients and athletes who chose to train with me during rather than follow their own training protocol noticed superior results in hypertrophy and/or maintenance of strength/muscle mass when compared to those who had trained alone.