diff --git a/apps/wohrm/app.js b/apps/wohrm/app.js
index 30f872066..5a9264f0b 100644
--- a/apps/wohrm/app.js
+++ b/apps/wohrm/app.js
@@ -5,96 +5,29 @@ const Setter = {
     LOWER: 'lower'
 };
     
-const shortBuzzTimeInMs = 100;
+const shortBuzzTimeInMs = 50;
 const longBuzzTimeInMs = 200;
 
-let upperLimit = 130;
-let lowerLimit = 100;
+let upperLimit = 90;
+let upperLimitChanged = true;
+
+let lowerLimit = 50;
+let lowerLimitChanged = true;
+
 let limitSetter = Setter.NONE;
+
 let currentHeartRate = 0;
 let hrConfidence = -1;
+let hrOrConfidenceChanged = true;
+
 
 let setterHighlightTimeout;
 
-function renderUpperLimitBackground() {
-  g.setColor(1,0,0);
-  g.fillRect(125,40, 210, 70);
-  g.fillRect(180,70, 210, 200);
-
-  //Round top left corner
-  g.fillEllipse(115,40,135,70);
-
-  //Round top right corner
-  g.setColor(0,0,0);
-  g.fillRect(205,40, 210, 45);
-  g.setColor(1,0,0);
-  g.fillEllipse(190,40,210,50);
-
-  //Round inner corner
-  g.fillRect(174,71, 179, 76);
-  g.setColor(0,0,0);
-  g.fillEllipse(160,71,179,82);
-
-  //Round bottom
-  g.setColor(1,0,0);
-  g.fillEllipse(180,190, 210, 210);
-}
-
-function renderCurrentHearRateBackground() {
-  g.setColor(1,1,1);
-  g.fillRect(45, 110, 165, 140);
-  g.setColor(0,0,0);
-  g.setFontVector(13);
-  g.drawString("Current:" , 65,117);
-}
-
-function renderLowerLimitBackground() {
-  g.setColor(0,0,1);
-  g.fillRect(10, 180, 100, 210);
-  g.fillRect(10, 50, 40, 180);
-
-  //Rounded top
-  g.setColor(0,0,1);
-  g.fillEllipse(10,40, 40, 60);
-
-  //Round bottom right corner
-  g.setColor(0,0,1);
-  g.fillEllipse(90,180,110,210);
-
-  //Round inner corner
-  g.setColor(0,0,1);
-  g.fillRect(40,175,45,180);
-  g.setColor(0,0,0);
-  g.fillEllipse(41,170,60,179);
-
-  //Round bottom left corner
-  g.setColor(0,0,0);
-  g.fillRect(10,205, 15, 210);
-  g.setColor(0,0,1);
-  g.fillEllipse(10,200,30,210);
-}
-
-function renderButtonIcons() {
-  g.setColor(1,1,1);
-  g.setFontVector(14);
-
-  // + for Btn1
-  g.drawString("+", 222,50);
-
-  // Home for Btn2
-  g.drawLine(220, 118, 227, 110);
-  g.drawLine(227, 110, 234, 118);
-
-  g.drawPoly([222,117,222,125,232,125,232,117], false);
-  g.drawRect(226,120,229,125);
-
-  // - for Btn3
-  g.drawString("-", 222,170);
-}
-
 function drawTrainingHeartRate() {
   //Only redraw if the display is on
   if (Bangle.isLCDOn()) {
+    renderButtonIcons();
+  
     renderUpperLimit();
   
     renderCurrentHeartRate();
@@ -108,18 +41,50 @@ function drawTrainingHeartRate() {
 }
 
 function renderUpperLimit() {
-  if(limitSetter === Setter.UPPER){
-    g.setColor(1, 1, 0);
-  } else {
-    g.setColor(1, 1, 1);
-  }
+  if(!upperLimitChanged) { return; }
+  
+  g.setColor(255,0,0);
+  g.fillRect(125,40, 210, 70);
+  g.fillRect(180,70, 210, 200);
 
+  //Round top left corner
+  g.fillEllipse(115,40,135,70);
+
+  //Round top right corner
+  g.setColor(0,0,0);
+  g.fillRect(205,40, 210, 45);
+  g.setColor(255,0,0);
+  g.fillEllipse(190,40,210,50);
+
+  //Round inner corner
+  g.fillRect(174,71, 179, 76);
+  g.setColor(0,0,0);
+  g.fillEllipse(160,71,179,82);
+
+  //Round bottom
+  g.setColor(255,0,0);
+  g.fillEllipse(180,190, 210, 210);
+
+  if(limitSetter === Setter.UPPER){
+    g.setColor(255,255, 0);
+  } else {
+    g.setColor(255,255,255);
+  }
   g.setFontVector(10);
-  g.drawString("Upper : " + upperLimit, 130,50);
+  g.drawString("Upper  : " + upperLimit, 130,50);
+  
+  upperLimitChanged = false;
 }
   
 function renderCurrentHeartRate() {
+  if(!hrOrConfidenceChanged) { return; }
+  
+  g.setColor(255,255,255);
+  g.fillRect(45, 110, 165, 140);
+  g.setColor(0,0,0);
   g.setFontVector(13);
+
+  g.drawString("Current:" , 65,117);
   g.setFontAlign(1, -1, 0);
   g.drawString(currentHeartRate, 155, 117);
 
@@ -128,6 +93,32 @@ function renderCurrentHeartRate() {
 }
   
 function renderLowerLimit() {
+  if(!lowerLimitChanged) { return; }
+  
+  g.setColor(0,0,255);
+  g.fillRect(10, 180, 100, 210);
+  g.fillRect(10, 50, 40, 180);
+
+  //Rounded top
+  g.setColor(0,0,255);
+  g.fillEllipse(10,40, 40, 60);
+
+  //Round bottom right corner
+  g.setColor(0,0,255);
+  g.fillEllipse(90,180,110,210);
+
+  //Round inner corner
+  g.setColor(0,0,255);
+  g.fillRect(40,175,45,180);
+  g.setColor(0,0,0);
+  g.fillEllipse(41,170,60,179);
+
+  //Round bottom left corner
+  g.setColor(0,0,0);
+  g.fillRect(10,205, 15, 210);
+  g.setColor(0,0,255);
+  g.fillEllipse(10,200,30,210);
+
   if(limitSetter === Setter.LOWER){
     g.setColor(255,255, 0);
   } else {
@@ -135,9 +126,13 @@ function renderLowerLimit() {
   }
   g.setFontVector(10);
   g.drawString("Lower  : " + lowerLimit, 20,190);
+  
+  lowerLimitChanged = false;
 }
   
 function renderConfidenceBars(){
+  if(!hrOrConfidenceChanged) { return; }
+  
   if(hrConfidence >= 85){
       g.setColor(0, 255, 0);
   } else if (hrConfidence >= 50) {
@@ -152,6 +147,24 @@ function renderConfidenceBars(){
   g.fillRect(165, 110, 175, 140);
 }
   
+function renderButtonIcons() {
+  g.setColor(255,255,255);
+  g.setFontVector(14);
+
+  // + for Btn1
+  g.drawString("+", 222,50);
+
+  // Home for Btn2
+  g.drawLine(220, 118, 227, 110);
+  g.drawLine(227, 110, 234, 118);
+
+  g.drawPoly([222,117,222,125,232,125,232,117], false);
+  g.drawRect(226,120,229,125);
+
+  // - for Btn3
+  g.drawString("-", 222,165);
+}
+  
 function buzz()
 {
   if(currentHeartRate > upperLimit)
@@ -161,7 +174,7 @@ function buzz()
      setTimeout(() => { Bangle.buzz(shortBuzzTimeInMs); }, shortBuzzTimeInMs);
   }
 
-  if(currentHeartRate < upperLimit)
+  if(currentHeartRate < lowerLimit)
   {
      Bangle.buzz(longBuzzTimeInMs);
      setTimeout(() => { Bangle.buzz(longBuzzTimeInMs); }, longBuzzTimeInMs);
@@ -169,6 +182,7 @@ function buzz()
 }
   
 function onHrm(hrm){
+  hrOrConfidenceChanged = (currentHeartRate !== hrm.bpm || hrConfidence !== hrm.confidence);
   currentHeartRate = hrm.bpm;
   hrConfidence = hrm.confidence;
 }
@@ -178,6 +192,10 @@ function setLimitSetterToLower() {
 
   limitSetter = Setter.LOWER;
   console.log("Limit setter is lower");
+  
+  upperLimitChanged = true;
+  lowerLimitChanged = true;
+  
   renderUpperLimit();
   renderLowerLimit();
 }
@@ -187,6 +205,10 @@ function setLimitSetterToUpper() {
 
   limitSetter = Setter.UPPER;
   console.log("Limit setter is upper");
+  
+  upperLimitChanged = true;
+  lowerLimitChanged = true;
+  
   renderLowerLimit();
   renderUpperLimit();
 }
@@ -194,6 +216,10 @@ function setLimitSetterToUpper() {
 function setLimitSetterToNone() {
   limitSetter = Setter.NONE;
   console.log("Limit setter is none");
+  
+  upperLimitChanged = true;
+  lowerLimitChanged = true;
+  
   renderLowerLimit();
   renderUpperLimit();
 }
@@ -205,10 +231,12 @@ function incrementLimit(){
     upperLimit++;
     renderUpperLimit();
     console.log("Upper limit: " + upperLimit);
+    upperLimitChanged = true;
   } else if(limitSetter === Setter.LOWER) {
     lowerLimit++;
     renderLowerLimit();
     console.log("Lower limit: " + lowerLimit);
+    lowerLimitChanged = true;
   }
 }
   
@@ -219,10 +247,12 @@ function decrementLimit(){
     upperLimit--;
     renderUpperLimit();
     console.log("Upper limit: " + upperLimit);
+    upperLimitChanged = true;
   } else if(limitSetter === Setter.LOWER) {
     lowerLimit--;
     renderLowerLimit();
     console.log("Lower limit: " + lowerLimit);
+    lowerLimitChanged = true;
   }
 }
   
@@ -246,35 +276,23 @@ Bangle.on('lcdPower', (on) => {
   if (on) {
     Bangle.drawWidgets();
     // call your app function here
-    renderLowerLimitBackground();
-    renderCurrentHearRateBackground();
-    renderUpperLimitBackground();
-    renderButtonIcons();
     drawTrainingHeartRate();
   }
 });
   
-g.clear();
-Bangle.loadWidgets();
-Bangle.drawWidgets();
-
-renderLowerLimitBackground();
-renderCurrentHearRateBackground();
-renderUpperLimitBackground();
-renderButtonIcons();
-  
-setWatch(switchOffApp, BTN2, {repeat:false,edge:"falling"});
-  
-setWatch(incrementLimit, BTN1, {edge:"rising", debounce:50, repeat:true});
-  
-setWatch(decrementLimit, BTN3, {edge:"rising", debounce:50, repeat:true});
-  
-setWatch(setLimitSetterToLower, BTN4, {edge:"rising", debounce:50, repeat:true});
-  
-setWatch(setLimitSetterToUpper, BTN5, { edge: "rising", debounce: 50, repeat: true });
-
 Bangle.setHRMPower(1);
 Bangle.on('HRM', onHrm);
  
+setWatch(incrementLimit, BTN1, {edge:"rising", debounce:50, repeat:true});
+setWatch(switchOffApp, BTN2, {repeat:false,edge:"falling"});
+setWatch(decrementLimit, BTN3, {edge:"rising", debounce:50, repeat:true});
+setWatch(setLimitSetterToLower, BTN4, {edge:"rising", debounce:50, repeat:true});
+setWatch(setLimitSetterToUpper, BTN5, { edge: "rising", debounce: 50, repeat: true });
+
+g.clear();
+Bangle.loadWidgets();
+Bangle.drawWidgets();
+drawTrainingHeartRate();
+
 // refesh every sec
-setInterval(drawTrainingHeartRate, 1000);
\ No newline at end of file
+setInterval(drawTrainingHeartRate, 1000);