The questions to ask yourself the next time you're feeling 'stuck'. Krakenimages.com/ ShutterstockIf you train regularly, your progress will eventually slow and personal bests will become harder to beat. When this happens, it’s tempting to start a completely new training programme – but this is usually the wrong move.To understand why, it’s important to know how progress happens in the first place.Exercise causes both immediate responses and long-term changes in your body. The body’s immediate responses to exercise are pretty obvious – an increased heart rate, breathing faster and your muscles feeling warmer. These short-term responses gradually settle back to normal after you finish training. But when an exercise is repeated over weeks, the short-term responses we experience lead to longer-lasting physiological changes (called adaptations). These adaptations make the body stronger and more efficient. This is why a weight that once felt hard to lift feels easier after a few weeks or why you’re able to run a mile 30 seconds faster than you did a month ago. If you continue doing the same training that produced your initial fitness gains, you can maintain the adaptations. However, over time, your progress will plateau because your body needs a greater training stimulus to drive further adaptations.This gradual increase in the demands placed on your body is known as “progressive overload”. The increase can be small – such as adding a little weight or completing a couple more reps. If you find your progress has stalled, the first question to ask yourself is whether you’re truly applying the principle of progressive overload. Here’s how you can figure this out.If you do resistance training, record the weight, repetitions (reps) and sets you perform for each exercise at every session. This gives you a baseline to track your progress against.At your next session, you can start applying progressive overload. Choose a rep range, such as eight to ten reps. Using your records as a guide, select a weight you can lift for eight reps with good technique, while feeling you could still manage another one or two reps.Over the following sessions, gradually add reps using the same weight. Even one extra rep on one set is progress. When you can complete ten reps on every set with good technique, you are ready to increase the weight and drop the rep target back to eight. This is known as double progression, because you progressively increase repetitions before increasing the weight. Increasing the reps before increasing the weight shows that you’re becoming stronger. Progressive overload can also be applied to endurance exercise, such as running, cycling or swimming. To start with, track your distances and pace to get a sense of where your fitness currently is. Progressive overload can then be applied by performing longer sessions, training more often or increasing your pace. It’s a good idea to increase only one of these at a time. This makes it easier to see what’s working and reduces injury risk. Track your workouts to see whether you are progressing. PeopleImages/ Shutterstock A sensible rule of thumb is to limit your weekly increase in distance or time to no more than 10%. For example, if you usually run 25 miles per week, keep the weekly increase to about 2.5 miles.You can track your progress by seeing whether you can cover the same distance in less time, or complete the same session at a lower heart rate or with less perceived effort. Improvements in any of these measures indicates that your fitness is improving.Progress or change?If your progress stalls and you are not seeing small improvements, there are a couple of reasons why this may be happening.Performance naturally fluctuates due to a range of factors including fatigue, stress, illness and lack of sleep. When this happens, doing more isn’t the answer. A large increase in training will only create more fatigue that will cause a drop off in performance. In extreme cases, this decline can take weeks or even months to recover from.As a rule of thumb, if you’ve made no progress for three to four weeks, try doing an easy training week – sometimes called a “deload week”. This involves doing less training than usual to reduce accumulated fatigue. This can be done by doing fewer training sessions that week, or doing less during a session than you normally would do (such as half the number of sets you would usually complete, for example). Athletes often do this before a major competition. If your performance returns to normal or gets better after a reduced training week, fatigue was the problem – not your programme.But if progress has truly stalled after an easier week, try changing one thing at a time. This could involve swapping out one exercise or session in your training plan, rather than starting a completely new programme.Consistency is important whether you’re training for a specific goal or you just want to improve your overall fitness. This is because adaptations happen when a specific exercise is done repeatedly under increasing demands.Changing your training programme entirely makes it difficult to know if you’ve progressed because you can’t make a direct comparison. For example, if you swap your usual strength training session for a body pump class, you won’t know for sure if your strength has truly improved because the exercises and style of training are different.Changing your programme becomes necessary is if you have a new goal or have experienced an injury. If boredom is the problem, consider changing how you train rather than what you train. For example, try doing shorter sessions, working with a personal trainer or updating your playlist. So if you want to keep improving your fitness, don’t throw out your training plan at the first sign of a plateau.Paul Hough does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.