HIIT workouts for older adults: A guide to safe and effective high-intensity interval training

Known for its ability to deliver effective results in less time than traditional workouts, HIIT is a big "hit" with younger fitness enthusiasts. But here's the good news: HIIT workouts can benefit older adults too. Here are some tips for older adults to make this style of exercise safe, effective, and rewarding.

What is HIIT?

High-intensity interval training (HIIT) is a workout style that alternates between intervals of intense effort and recovery. The goal of HIIT is to push your body hard during the high-intensity intervals and allow it to recover during intervals of low- to moderate-intensity activity.

During the intense bursts of exercise in a HIIT session, your heart rate rises. A simple way to judge if you are exercising at high intensity is to use the talk test. If you can sing while exercising, you're at low intensity. If you can have a conversation while exercising, your effort is moderate. When you can't say more than a few words without having to take a breath, you're working at high intensity.

During recovery periods, your heart rate dips from that peak, but still stays elevated relative to your baseline. This sustained increase means a HIIT workout burns more calories and improves cardiovascular fitness more efficiently than sustained moderate-intensity exercise. The structure of HIIT makes it highly efficient, helping you gain maximum benefits in minimal time.

A HIIT workout consists of four essential parts:

• a warm-up of lower-intensity movements targeting the same muscles as the main workout
• high-intensity intervals during which you increase speed, resistance, or incline to maximize your effort
• recovery intervals, or active rest periods, equal in length or slightly longer than high intensity intervals
• a cool-down with light activity like walking or marching.

One of the most appealing features of high-intensity interval training is its flexibility. Cardio, strength, or combination workouts can be turned into interval sessions by increasing incline, speed, or resistance to create high-intensity intervals and alternating those with recovery intervals.

Key benefits of HIIT: Boosting cardiovascular health and strength

HIIT workouts offers significant health benefits. Below are some key benefits of incorporating HIIT into your routine:

• Improves aerobic fitness. HIIT has been shown to increase VO2 max, a measure of how much oxygen your body consumes while exercising and the best available measure of aerobic fitness. This increase occurs across age groups.
• Benefits heart health. Interval training strengthens the heart muscle and improves cardiovascular health. The periodic boosts to your heart rate during HIIT sessions promote more efficient oxygen use.
• Boosts metabolic function. HIIT improves the function of mitochondria — tiny energy generators found in every cell of your body.
• Builds muscle. According to studies, HIIT can increase fat-free mass, which includes muscle, by 1% to 3%. This is important for older adults who begin to lose muscle at increased rates as they age.
• Preserves muscle power. HIIT helps maintain fast-twitch muscle fibers, which are essential for quick, explosive movements. This is especially important because fast-twitch fibers naturally decline with age, making activities that require sudden bursts of energy more challenging.
• Fast results. Research shows that HIIT can lead to fitness benefits faster than traditional, steady-state workouts. A 20-minute HIIT session burns more calories and strengthens the heart more than 20 minutes of moderate-intensity exercise.

Modifications and precautions: Adapting HIIT to your abilities

Remember that intensity depends on your fitness level — what feels intense for you might feel different to someone else. Avoid trying to keep up with younger or more experienced athletes. Instead, focus on gradually increasing your own challenge. Even small bursts of effort can boost your fitness.

If you're older, or haven't exercised in a while, modify high-intensity interval training as needed to suit your current fitness level. For example, you may not need to jog as fast or use as much resistance to raise your heart rate as the person next to you at the gym.

Consult your doctor before starting a HIIT program, especially if you have any health conditions. If you have heart disease, diabetes, or high blood pressure, be extra cautious and consult a medical professional before incorporating high-intensity efforts into your routine. Call 911 right away if you experience upper body discomfort including chest pain, shortness of breath, or faintness during or after exercising.

In terms of frequency, you don't have to do HIIT workouts every day, nor should you. In fact, HIIT is only recommended two to three times a week.

Getting started with HIIT

Getting started with HIIT as an older adult doesn't have to be intimidating. You can get all the benefits of HIIT just by tweaking whatever exercise you do today. The key is to begin with manageable intervals and gradually increase the intensity as your fitness improves.

For example, if you're used to walking for 30 minutes, try walking at your normal pace for five minutes, then walk as fast as you can or jog for one minute. Afterward, return to your usual pace for three minutes. Repeat this cycle several times.

If your preferred exercise is swimming, you might try to alternate one leisurely lap with one or two laps swimming at a challenging pace. Work your way up to repeating this pattern for 30 minutes.

As you get stronger, you can increase the time and intensity of the higher-intensity intervals while reducing the recovery periods. Always listen to your body and progress at a pace that feels comfortable.

Some soreness after a workout is normal, but let your doctor know if you experience persistent or intense muscle pain that starts during a workout or right afterward, or if your muscle soreness lasts for more than one to two weeks.