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Science Here’s the Most Impactful Health and Fitness Research of 2021 and What It Means For Your Routine

We asked our experts on the Tonal Advisory Board and in-house Strength Institute to share the most meaningful research and how you can apply it to everyday life.

Image showing three people performing strength training exercises and badge reading "2021 Top Research"

If you’ve ever scoured the internet for new science-backed info that may help you with your fitness journey, you know the sheer volume of research coming out in exercise science every day can be overwhelming. In such a dynamic environment, we asked the Tonal Advisory Board Members, renowned experts in their fields, along with resident performance pros from the Tonal Strength Institute what health and fitness research articles were the most impactful must-reads for you in 2021. 

Here is our line-up:

Brad Schoenfeld, Ph.D., hypertrophy and strength expert and Tonal advisory board member 

Article: Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

While many studies published in 2021 have important implications for training, Schoenfeld’s standout was the systematic review and meta-analysis he co-authored in the Journal of Sport and Health Science on training to failure. The researchers found that if you perform sets that are relatively close to failure, meaning that you have approximately 2 or 3 reps in reserve (RIR), then there’s likely no appreciable difference between strength training and hypertrophy training. So wave goodbye to training to sheer exhaustion. You can see gains without completely emptying the tank.

Schoenfeld discusses opportunities for growth in this field on his blog. Stay tuned for research coming out in partnership with the Tonal Strength Institute and Schoenfeld’s Human Performance Lab at CUNY Lehman College as we explore topics in hypertrophy in 2022.

The takeaway: Always training until failure can lead to serious fatigue, particularly on multi-joint movements (deadlift, squat, bench press). “Alternating periods using very high levels of effort with reduced levels of effort potentially may promote supercompensation of gains without devolving into an overtrained state,” says Schoenfeld. Simply put, there is a time and place for training until failure, but it doesn’t need to be all the time.

Image of a man performing a chest fly exercise on the Tonal trainer.
David T. Martin, Ph.D., Chief Scientist & Director of Performance at Apeiron Life and Tonal advisory board member

Article: Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

If you’re not convinced of the above research’s impact yet, Martin offers some unique perspectives and insights on how the same paper relates to workouts on Tonal. This paper addresses the very important question: Should resistance training be performed to repetition failure if the goal is muscular strength and hypertrophy? 

“After reaching repetition failure, there can be a fatigue residual, which makes it difficult to perform a subsequent high-quality set of exercises,” Martin notes. The rest of your workout may suffer after taking some exercises to failure. 

Martin describes Tonal as a safe and effective approach to lifting with these results in mind. “Put the muscle under tension,” he says, “focus on good technique, and get close to but don’t achieve repetition failure.”

The takeaway: “Working to repetition failure does not seem to be required to promote desirable gains in hypertrophy and strength,” says Martin. “This is nice to know because the final repetitions of an exercise leading to repetition failure are mentally demanding and could be considered riskier from an injury perspective.” 

Louisa Nicola, Ph.D., neuroscientist/ neurophysiologist and Tonal advisory board member

Article: Exercise plasma boosts memory and dampens brain inflammation via clusterin

Nicola cites a study published in Nature, one of the most respected peer-reviewed science journals available. In this study, the researchers found that ‘runner plasma,’ collected from voluntarily running mice and infused into sedentary mice, reduces baseline neuroinflammatory gene expression and experimentally induced brain inflammation. 

Nicola shares this fascinating study because “these findings demonstrate the existence of anti-inflammatory exercise factors that are transferable, target the cerebrovasculature and benefit the brain, and are present in humans who engage in exercise,” she says.

The takeaway: There are vast benefits of exercise on brain health and this study shows that the plasma collected not only lowers inflammatory biomarkers but also could be transferred to other mice for their benefit—important findings that support the growing implications of exercise as medicine in the future.

Image of a woman running
Troy Taylor, Senior Director of the Tonal Strength Institute

Article: Megastudies improve the impact of applied behavioural science

Taylor was also intrigued by a megastudy that came out in Nature. This revolutionary study explored the exercise behaviors of over 60,000 gym-goers in 46 states and the efficacy of different interventions in increasing physical activity levels. Researchers found that out of 53 experimental conditions, 45 percent were successful in increasing exercise participation. Interestingly, there was a 27-percent increase in exercise when gym-goers were rewarded for returning to the gym after a workout, a 25-percent increase in exercise when there was a larger reward involved, and a 24-percent increase in exercise when participants were told that the majority of Americans exercise and that number is growing.

The takeaway: “This is one of the first studies to explore different behavioral interventions across such a large sample size, giving us insights into what we can accomplish at Tonal to help you reach your goals, but it can also give you ideas of how to navigate times when it’s harder to stick to your routine when life takes over,” says Taylor.

Lauren Benson, Ph.D., Senior Manager, Research of the Tonal Strength Institute 

Article: The future of in-field sports biomechanics: wearables plus modelling compute real-time in vivo tissue loading to prevent and repair musculoskeletal injuries

Benson found a review article in Sports Biomechanics to be an excellent example of how wearable technology and artificial intelligence are revolutionizing exercise science for more personalized and real-world outcomes. When we exercise and load our muscles, tendons, and bones, we are hoping for strength gains and better overall fitness. But individual responses to exercise will vary and sometimes injuries occur. 

The takeaway: “This article highlights the ways that monitoring exercise through a combination of connected fitness devices and AI—like Form Feedback on Tonal—will lead to real-world and real-time evaluation of the quality and effectiveness of exercise,” says Benson. We are excited to be a part of this new wave of technology at Tonal that can not only improve your fitness but also protect you from injury. 

Image of woman doing cross body rotation, deadlift, and bench press with form feedback cues of range of motion, positioning, and pacing
Susie Reiner, Ph.D. Candidate, Science Writer at Tonal

Article: Sleep, Sedentary Behavior, Physical Activity, and Cardiovascular Health: MESA

Reiner shares the findings of the epidemiological study published in Medicine & Science in Sport & Exercise. The study explored the impact of sleep and physical activity habits on cardiovascular health. The researchers measured sleep and activity objectively with the use of accelerometers and cardiovascular health through lifestyle behaviors, anthropometric measurements, and biomarkers such as blood pressure and cholesterol—not an easy feat with over 1,700 participants. 

Researchers found that replacing only 30 minutes of sedentary behavior during the day with sleep, light-intensity physical activity, or moderate to vigorous exercise improved cardiovascular health. This article is particularly compelling because it used data from a larger project called the Multi-Ethnic Study on Atherosclerosis (MESA) – sampling a wide, ethnically-diverse population that is not often equally represented in research. 

The takeaway: “Whether it’s fitting in a quick 30-minute nap, a stroll around the block, or a heart-pumping workout on Tonal, that time for yourself is essential in improving longevity and quality of life in the long run,” says Reiner.