When Alyssa Kirby signed up for the 2018 Medtronic Twin Cities Marathon, a 26.2-mile jaunt through Minneapolis and St. Paul, she had high hopes of realizing a lifelong dream. She’d grown up on mile 18 of the course, where her parents held annual marathon-day parties featuring a runners’ water station, music, a bonfire, and snacks for spectators. After years of cheering herself hoarse, she longed to be on the runners’ path.
Kirby had tried and failed to complete the race twice before: Pain from uterine prolapse, a complication from the birth of her first daughter, had sidelined her. In 2017, after her fourth child was born, the 36-year-old underwent a hysterectomy and surgery to repair the damaged tissues. She felt good physically and mentally, so in 2018 she and her younger sister decided to give it another shot.
Training was tough, says Kirby, a small-business owner, and so was the race. Her sister was powering through the tail end of a flu, and 13 miles in, Kirby began feeling pain and pressure in her abdomen. “I started doubting everything I had trained for,” she says. “I started doubting my ability to finish or even continue.”
But thanks to a midrace pep talk from their trainer, who met them at their parents’ house at mile 18 — and a mix of walking and running — the sisters crossed the finish line, holding hands and crying with joy.
In the following days, though, Kirby’s lower-abdominal pressure didn’t let up. She’d pushed her body too far. Luckily, there was no permanent damage to the surgical repairs of the previous year, but her doctor offered two prescriptions: rest to recover — and, going forward, low-impact exercise only. No running. No lifting heavy weights. Nothing strenuous.
This was a setback for the woman who’d found a font of well-being and confidence in running. “I loved how strong my body felt as my feet hit the pavement,” says Kirby. “And I loved how my body transformed. I felt so strong and so powerful. But now I had to be incredibly careful. That meant no running. Of any kind. Even short distances, even at a slow pace.
“So, I stopped doing everything.”
Kirby’s experience, unfortunately, is not unique.
Many people are prescribed low-impact routines, even temporarily, for a variety of reasons, including injury rehabilitation, recovery after surgery, and prevention of joint-related pain, particularly as they age.
“That’s because stress and impact can cause damage to joint cushions, tendons, and muscles, especially if your musculoskeletal frame is not as durable or limber,” says orthopedic surgeon Nicholas DiNubile, MD, author of FrameWork: Your 7-Step Program for Healthy Muscles, Bones, and Joints.
But “low impact” is a loaded term; it may be viewed as overly restrictive and inferior to more rigorous regimens. As a result, many people instructed to perform low-impact training opt out of exercise altogether. DiNubile and other experts argue that this can lead to further immobility, injury, and loss of self-confidence.
In fact, when properly implemented, low-impact exercise includes opportunities to push your body, achieve goals, have fun, and feel good about yourself. It is not a step down from high-impact workouts.
Moreover, the benefits are not limited to people who are older or have injuries. We can all improve our fitness by incorporating low-impact routines.
Understanding Low Impact
Contrary to popular belief, the difference between high- and low-impact training isn’t in the effort each demands or the value it adds to your fitness, explains DiNubile. Rather, it describes the type of muscle contractions elicited and the forces exerted on your body.
Most of us imagine that our muscles operate like light bulbs — that they’re either switched on or switched off. In fact, muscles contract in three distinct ways:
- Concentric contractions occur when you shorten a muscle under a load. This is when your muscles are exerting force.
- Eccentric contractions occur when you lengthen a muscle under tension. This is when your muscles are absorbing force.
- Isometric contractions occur when you tighten a muscle without shortening or lengthening it.
A biceps curl helps illustrate the differences between the three contraction phases, says Mark Schneider, a personal trainer and strength coach specializing in injury rehab and trauma recovery. The concentric phase occurs while you curl the dumbbell up, from open elbow to closed elbow; the biceps muscle shortens. The eccentric phase occurs while you lower the weight; the muscle extends. The isometric phase occurs if you pause and hold the weight at any point in the movement between the completely opened and completely closed elbow.
But this is an oversimplified explanation. While the biceps muscle shortens, lengthens, and holds, other muscles in the arm and elsewhere are also contracting. A controlled biceps curl gives a balanced look at the types of contractions, but some activities emphasize certain phases over others.
Running — particularly running downhill — and doing plyometric work, like box jumps, emphasize eccentric contractions: Your muscles are primarily absorbing force. This amplification of force is incredibly powerful, says DiNubile.
Every time you take a step while running, your knee absorbs 5 to 7 pounds of impact for every pound you weigh. For a 150-pound person, that’s up to 1,050 pounds of force on your knees.
A healthy knee can withstand that force and recover from it. In the process, the tissues in and around that joint can grow stronger. But if that knee is compromised in some way — because of overuse, injury, a sedentary lifestyle, fatigue, aging, or even the wrong kind of footwear — it may be more difficult, or even impossible, to deal with the forces resulting from the eccentric-phase landing, lowering, and decelerating.
The impact reaches farther than the muscles bearing the brunt of the force. Joints, bones, connective tissues (like tendons and ligaments), internal organs (such as those supported by the pelvic-floor muscles), and even muscles that aren’t primarily used in the activity are all affected by that force. For instance, running can aggravate an injured shoulder.
This is where lower-impact training — exercises that emphasize concentric and isometric contractions while minimizing or eliminating eccentric forces — comes into play.
Impact vs. Intensity
Activities that emphasize concentric contractions include walking uphill, bicycling, or pushing a weighted sled — movements where your muscles are primarily producing force. Exercises that involve holding a position — think a plank, the top of a pull-up, or the top of a glute bridge — emphasize isometric muscle action, engaging (and potentially exhausting) the muscles while reducing eccentric force.
These types of movements offer valuable options to anyone with exercise restrictions: By limiting eccentric contractions, they are easy on joints and internal organs while still taxing the muscles and cardiovascular system.
People exercising without restrictions benefit, too. It’s tempting, at a time when plyometrics and boot-camp workouts are de rigueur in training facilities, to go all out with high-impact exercise — mistaking it for high intensity.
But intensity and impact are different things. You can perform high-impact work without engaging in a high-intensity routine. The reverse is also true: “You can have very-high-intensity workouts that are not high impact,” says DiNubile.
Cycling, swimming, rowing, strength training, and yoga are just a few types of exercise that offer virtually unlimited challenges to your muscles and cardiovascular system while producing minimal impact on your joints.
Even if you feel good, incorporating low-impact moves into your higher-impact regimen can act as an insurance policy. Focusing on concentric- and isometric-dominant exercises can shore up muscle strength and endurance. Mixing up muscle-contraction types can also ward off orthopedic problems down the road.
“Sometimes when I’m operating on someone’s knee, I’ll see significant areas of wear that weren’t bothering them,” DiNubile explains. “After the operation, I’ll say to them, ‘You have 50,000 miles left on your knee. Do you want to use it all up this year, or do you want it to last a lifetime?’”
Traditional cardio training is one area where people feel most limited when they receive a low-impact prescription. In large part, that’s because running — convenient, affordable, and effective — is considered by many to be the ultimate cardio workout.
But running is also one of the most high-impact cardio options. Unless you’re already fairly fit, injury-free, and adequately stable throughout the body, the forces incurred by running may sideline you before you can reap the cardio rewards.
“People say, ‘I’m going to run to get in shape,’” DiNubile notes. “It makes more sense to get in shape before you run.”
If running is off the table, as it was for Kirby, there are other ways to develop cardiovascular fitness.
Stationary bikes, elliptical trainers, stepmills, rowers, and other cardio machines are popular and effective indoor options. Lower-impact outdoor activities include hiking, cycling, sculling, ice skating, inline skating, and cross-country skiing.
Many group fitness classes are low impact: By staying in the saddle during indoor cycling classes, for instance, you can reduce shearing forces in the knees. Dance-inspired classes, like Zumba, can often be modified to eliminate jumping. Pool-based group workouts, like water aerobics, are the lowest-impact option. In fact, water workouts can reduce impact to virtually zero, providing “mild compression, joint support, and resistance in all directions,” says trainer Jolie Kobrinsky, CPT, a trainer and functional-fitness expert who works with people of all ages to help them “unstick” themselves from patterns of inactivity.
She recommends a pool or open-water swimming as “your first stop” for incorporating low-impact cardio. Lap swimming — for sprints or longer distances — is a great option on its own, but the pool is also a place to incorporate calisthenics: Jumping and running with the legs and torso underwater can significantly reduce the impact.
Turning up the intensity on almost any low-impact exercise can transform it into a cardio workout. For instance, lifting lighter weights faster and with fewer breaks can produce a notable cardio effect. Kobrinsky suggests the following ways to regulate the intensity of your favorite activity:
- Low-intensity steady-state (LISS) cardio: Perform 20 to 90 minutes of the activity of your choice, “at a pace that allows you to carry on a conversation,” she says.
- High-intensity interval training (HIIT): Try five to 10 rounds of a 30:90 split, meaning you perform 30 seconds of an activity at a high effort (8 to 10 rating of perceived effort, or RPE; heart-rate zone 4 or 5; difficulty holding a conversation), then 90 seconds of recovery at half that effort.
- Every minute on the minute (EMOM): Select a set number of reps to perform or, depending on the activity, a set distance to travel at the top of each minute, as quickly as you can with good form. Rest for the remainder of the minute when you’ve completed your set reps. Repeat for a set number of minutes. For example, perform 20 kettlebell swings at the start of each minute for 20 minutes, resting once you’ve completed the last swing in each round.
Low-Impact Strength Training
One of the most beneficial activities for people with exercise limitations, strength training can limit impact and also make your body more resilient to higher impact in the long term, says Schneider. The wide variety of exercises and variations that can build strength also make this style of training versatile.
Some movements — sled pushes, sled drags, rope pulls, and carries — are almost exclusively concentric, making them naturally low impact.
Most strength exercises, though, involve lowering and lifting, says DiNubile, so you won’t entirely eliminate the eccentric contractions associated with high-impact training.
But in the controlled context of a lifting routine, that’s not a problem: Unlike running or jumping, which can expose your joints to extreme eccentric forces, strength training allows you to practice eccentric movements slowly and deliberately. This can improve bone density, spur muscle growth, and engrain healthy movement patterns.
Schneider emphasizes the importance of building control in the eccentric and the isometric portions of a lift. “The transition from an uncontrolled eccentric to a concentric [contraction] is where the impact is,” he says.
In other words, using our biceps-curl example, don’t haphazardly lower the weight and bounce out of the bottom using momentum. Control the lowering phase, deliberately come to a pause in the transitional isometric phase, and then resume motion for the lifting phase. Schneider advises against increasing weight until you can control your current working weight in all three phases.
“Eccentrics teach control and build resilience. [They] can serve as a bridge to build strength as well as confidence in your strength.”
As with any form of exercise, proper execution is key: “Own each movement,” he says. “At no point during the lifting, lowering, or transition phase of any exercise should your muscles be passive.”
This requires paying attention to your body as you lift — no zoning out. Feel your working muscles contract and extend. Strive for the maximum range of motion you can perform with control and without pain. Focus on the alignment of your entire body, head to toe, on each lift.
Always terminate a set if you feel pain anywhere. Resist the temptation to progress too fast, and never add weight to an exercise until you’re fully comfortable with the lighter weight.
Low-Impact Ancestral Movement
Modalities that involve foundational ancestral movements — think yoga and primal-exercise philosophies such as MovNat, or Natural Movement Fitness — favor concentric and isometric contractions. By improving the body’s ability to work at its best, these training approaches inherently limit impact.
Ancestral movements emphasize a balance of tension and relaxation — never too rigid, never too loose — to enhance efficiency and effectiveness. They can build stability, mobility, balance, and body awareness; they can be modified to promote cardio, strength, or both types of biophysical adaptations without increasing impact.
Again, proper alignment and form are imperative whether you are holding downward-facing dog, pivoting to throw a punch, or crawling across the gym floor, says MovNat master trainer Kimberly Alexander.
“Quality movement is very therapeutic. Pay close attention to your breath” as a signal of compromised movement quality, she advises. “If you’re not breathing, you’re not moving well.”
The key, says Stephen Schilling, a martial arts and yoga instructor, is “leaving your ego at the door.” Foundational movements are inherently a practice: They might be challenging, but they should never be forced.
- Yoga: There are many different styles of yoga; some, like vinyasa and ashtanga, include vigorous, fast-paced flows that can offer high-intensity workouts. To limit impact, focus on alignment, slowing your own pace as needed to execute each asana, or pose, with precision, says Schilling. Other styles, like yin and restorative, operate at a slower pace with longer holds. Although the intensity is lower, relaxing too deeply or forcing your way into a stretch can damage impaired joints. Support yourself as needed with bolsters, blocks, and blankets to control your range of motion and prevent injuries.
- Natural Movement: Crawling, climbing, hanging, throwing, catching, lifting, and carrying are natural-movement patterns that work the full body in a range of planes. One of Alexander’s favorite low-impact combos pairs 30 seconds of crawling with 30 seconds of hand carries (with a kettlebell, dumbbell, sandbag, or other weighted object) for six rounds.
Getting the Most Out of Your Workout
Impact is frequently confused with intensity, but the two are not synonymous. A high-intensity workout can be low impact, and vice versa. These definitions help clarify the difference, so you make smart training choices.
Impact: Describes the forces exerted on, and exerted by, the body. Impact is measured in terms of the emphasis on eccentric, concentric, and isometric muscle contractions.
Low impact: Exercise that minimizes absorption of eccentric forces and emphasizes concentric or isometric muscle contractions. This type of training can help you get and stay fit for the long haul, as well as keep you active and strong while recovering from an injury. Examples include swimming, cycling, pushing a weighted sled, using battle ropes, performing plank holds, and eccentric weight training.
High impact: Exercise that emphasizes eccentric contractions resulting from absorbing external forces. This powerful training can elicit a strong, adaptive, muscle-building response when paired with adequate recovery. When the body can’t recover, the wear and tear can be extreme. Examples include running, jumping, plyometrics, and the lowering phase of strength-training exercises, especially with heavy weight.
Intensity: How much effort a workout requires in terms of heart rate and oxygen expenditure. Intensity is measured as a percentage of your maximum heart rate, a marker reflecting how hard your body is working during
Low intensity: If you have conducted an active metabolic assessment (AMA) and use a heart-rate monitor, low intensity means you are performing within heart-rate zone 1 to 2. On a rate of perceived exertion (RPE) scale (1 corresponding to very easy effort and 10 to very difficult), low intensity falls in the range of 1 to 3. Such a workout would allow you to easily maintain a conversation. Low-intensity training is commonly and beneficially performed in what is known as a “steady state,” in which the heart rate remains fairly low and stable. Called LISS — low intensity, steady state — this type of cardio includes a leisurely walk or bike ride.
High intensity: If you have completed an AMA and use a heart-rate monitor, high intensity means you are performing within zone 4 to 5. On an RPE scale, high intensity pushes you into 8 to 10. High-intensity training is popularly performed in an interval fashion known as HIIT (high-intensity interval training) because the rest intervals give you an opportunity to recover briefly in order to keep your intensity high during work intervals.|A year after completing the marathon, Kirby says her sense of achievement is tempered by the loss she still feels after having to give up running. For her and many others, the psychological effect of changing a routine and embracing low-impact training is more challenging than the physical effect.
DiNubile and Schneider note that going into your training with a beginner’s mindset will make a significant difference.
While the sense of loss you may feel by limiting jumping and running — and potentially giving up an activity you love — is real, it’s helpful to also focus on the new things you can learn and the new ways you can grow. There’s a lot of fitness waiting to be gained, and for every one of us, low impact is a great way forward.
This originally appeared as “Low Impact, High Value” in the October 2019 print issue of Experience Life.