How to minimise muscle mass loss and maximise strength retention during isolation

We’re all going through a challenging period right now with the COVID-19 pandemic, and it’s affecting strength athletes’ normal training routines – even more so than endurance-based athletes, who are still able to go out for a run or cycle in most countries.

One of the main concerns of strength athletes is losing ‘gains’, but there are some key strategies that we can focus on to minimise muscle mass and strength loss.

Minimum effective dose

First, we have training. It is important for strength athletes to focus on exercises specific to their sport. But a key question arises: what is the minimal effective dose? While we don’t want athletes to completely stop training, we also don’t want to push them too hard because know excess training can compromise their immune system (see webinar on exercise immunology). We need to find the balance, so having an idea of the minimal effective dose can be useful in guiding athletes.

One study looked at the effect of detraining on muscle mass and strength in both young and older adults (1). First, participants performed a 16-week resistance training programme that consisted of 27 sets of knee extensions. After the 16 weeks of training, participants were randomised to perform three sets per week (one-ninth of their original training volume), or to cease training for 32 weeks. The researchers found that training one-ninth of their original volume during the 32-week period prevented decrements in muscle mass in young adults, while those who did not train, lost 30 per cent of their original muscle size. In older adults, they needed one-third of their original training volume to maintain muscle mass and one-ninth to maintain strength. The key learning here is that it is possible to attenuate any losses by doing much less volume than normal.

A more recent systematic review suggests that performing a single set of 6-12 repetitions, with loads ranging from 70-85 per cent 1RM, two to three times a week, with a high-intensity effort (9/10 on the RPE scale) for 8-12 weeks, can produce suboptimal but meaningful increases in squat and bench press 1RM strength in resistance-trained men (2). This may also be a good approach if you have equipment and try to maintain maximal strength without pushing your body too much.

If athletes don’t have equipment, body weight movements are good for overall physical fitness and they can be creative in adding load to support strength retention as much as possible; for example, by using heavy packed bags, 5L water bottles, or even bricks.

Compromising muscle mass – the interference effect

Strength-based athletes also need to be mindful of the interference effect of other types of exercise. Some athletes may be training in a way that adversely affects their muscle mass and strength. With the current restrictions, these athletes may not have access to their usual training equipment, but they are able to go outside for a run and may choose to start running as a way to keep active. What they don’t realise is that this can compromise their muscle mass and strength if they don’t do it correctly

From a molecular level (Figure 1), the interference effect of endurance exercise seems to occur through AMPK-mediated phosphorylation of TSC2 Ser 1345 and Raptor Ser 792. These blunt the mechanical and nutritional stimulation of mTORC1 – the key driver for muscle protein synthesis.

mechanisms

Figure 1 – Endurance and resistance training adaptations: molecular signalling pathways (3).

Now, I’m not saying that these athletes can’t go for a run. It really depends how they implement running by considering frequency and duration. A 2012 meta-analysis showed that endurance exercise (more than 20-30 min) performed at a high frequency (more than 3 days per week) can be detrimental to muscle mass and strength (4). Researchers also suggest selecting an endurance-based activity that is performed at very high intensities because this will result in lower muscle mass decrements.

Effects of nutrition

Second, we have nutrition. Specifically for muscle, we know how important it is to maintain a consistent intake of good-quality protein with habitual meals to keep activating mTORC1 and avoid going into a catabolic state. Standard guidelines suggest 1.6 to 2g/kg body weight for strength-based athletes. The upper limit can even be exceeded a little to help maintain muscle mass, but also if an athlete struggles with satiety during this period of isolation.

We can take things a step further and really focus on how athletes are eating their protein. Although not specific to athletes, a nice study showed the effect of chewing on postprandial whole-body protein metabolism in elderly subjects (5). The key findings were that participants who were wearing dentures (poor chewing efficiency) experienced lower protein digestion and absorption rates than those with their normal teeth (good chewing efficiency) after eating a meat-based meal. Postprandial whole-body protein synthesis was also lower in participants wearing dentures than in dentate participants (30 per cent compared with 48 per cent of leucine intake), highlighting the importance of chewing your meat properly! Whether this whole-body protein synthesis translates to an enhanced muscle protein synthesis remains unclear, but we would expect to have seen that if they had measured it.

Now that athletes have more time, they can really focus on how they’re eating. They can incorporate this advice into a pre-eating routine (see below) to really get themselves into a relaxed state, which supports digestion and ensures they’re absorbing nutrients effectively.

pre eating routine

Such a simple mindful practice, but very powerful, especially if an athlete is struggling with gut-related issues.

Relaxation

Talking about relaxation, athletes also need to make sure they’re getting adequate sleep and are managing their stress levels. This is vital because it has been shown that stress (real-life events or perceived) can hugely impact recovery of muscle function after resistance exercise (6).

Even though we do have extra time on our hands, it can be harder to focus on consistent health patterns, and this uncertain situation that we’re in can raise anxiety levels. My recommendation for athletes is to use this extra time to experiment with active, but restorative, strategies like mindfulness, yoga, or deep breathing – this will only benefit them in the long term when they get back to their normal training/competition schedule.

In short, for all strength-based athletes out there: keep training, but be mindful of what and how much you’re doing. Keep it simple and don’t go chasing any new PBs right now (remember we need to keep our immune system happy). Focus on some exercises specific to your sport and view training/exercise as more of a way to maintain your overall health, both mental and physical. It’s also a good time to focus on any weaknesses you may have, like mobility. Keep focusing on nourishing meals, with good-quality protein evenly distributed throughout the day. More importantly, take the time to focus on how you’re eating and make sure you’re taking proactive steps to manage any anxiety or stress.

References

  1. Bickel CS et al (2011). Exercise dosing to retain resistance training adaptations in young and older adults. Med Sci Sports Exerc. 43(7):1177-1187.
  2. Androulakis-Korakakis P et al (2020). The minimum effective training dose required to increase 1RM strength in resistance-trained men: a systematic review and meta-analysis. Sports Med. 50(4):751-765.
  3. Perez-Schindler J et al (2014). Nutritional strategies to support concurrent training. Eur J Sport Sci. 15(1):41-52.
  4. Wilson JM et al (2012). Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. J Strength Cond Res. 26(8):2293-2307.
  5. Rémond D et al (2007). Postprandial whole-body protein metabolism after a meat meal is influenced by chewing efficiency in elderly subjects. Am J Clin Nutr. 85(5):1286:1292.
  6. Stults-Kolehmainen MA et al (2014). Chronic psychological stress impairs recovery of muscular function and somatic sensations over a 96-hour period. J Strength Cond Res. 28(7):2007-2017.